[[pp. 59345-59378]] National Primary Drinking Water Regulations; Radon-222

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

[Federal Register: November 2, 1999 (Volume 64, Number 211)]
[Proposed Rules]
[Page 59345-59378]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02no99-37]

[[Continued from page 59344]]

[[Page 59345]]

is included in the preamble for the proposed rule. EPA has conducted a
preliminary analysis on exposure and risks to NTNCWSs and is asking for
public comment on this preliminary analysis and on the proposed
exclusion of NTNCWSs. An analysis of the potential benefits and costs
of radon in drinking water for NTNCWSs is included in the docket for
this proposed rulemaking. (USEPA 1999m)

XIV. Administrative Requirements

A. Executive Order 12866: Regulatory Planning and Review

Under Executive Order 12866, ``Regulatory Planning and Review'' (58
FR 51,735 (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 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 E.O. 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 the proposal in
response to OMB suggestions or recommendations will be documented in
the public record.

B. Regulatory Flexibility Act (RFA)

1. Today's Proposed Rule
Under the Regulatory Flexibility Act (RFA), 5 U.S.C. 601 et seq.,
as amended by the Small Business Regulatory Enforcement Fairness Act
(SBREFA), EPA generally is required to conduct a regulatory flexibility
analysis describing the impact of the regulatory action on small
entities as part of rulemaking. Today's proposed rule may have
significant economic impact on a substantial number of small entities
and EPA has prepared an Initial Regulatory Flexibility Analysis (IRFA).
In addition, when preparing an IRFA, EPA must convene a Small Business
Advocacy Review (SBAR) Panel. A discussion of the Panel's
recommendations and EPA's response to their recommendations is shown in
Section 6.
2. Use of Alternative Small Entity Definition
The EPA is proposing that small CWS serving 10,000 people or less
must comply with the AMCL, and implement a MMM program (if there is no
state MMM program). 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 previously established under the RFA, 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 SBA 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 stated its intent to
establish this alternative definition for regulatory flexibility
assessments under the RFA for all drinking water regulations and has
thus used it for this radon in drinking water rulemaking. Further
information supporting this certification is available in the public
docket for this rule.

3. Background and Analysis

The RFA requires EPA to address the following when completing an
IRFA: (1) describe the reasons why action by the Agency is being
considered; (2) state succinctly the objectives of, and legal basis
for, the proposed rule; (3) describe, and where feasible, estimate the
number of small entities to which the proposed rule will apply; (4)
describe the projected reporting, record keeping, and other compliance
requirements of the rule, including an estimate of the classes of small
entities that will be subject to the requirements and the type of
professional skills necessary for preparation of reports or records;
(5) identify, to the extent practicable, all relevant Federal rules
that may duplicate, overlap, or conflict with the proposed rule; and
(6) describe any significant alternatives to the proposed rule that
accomplish the stated objectives of applicable statutes while
minimizing any significant economic impact of the proposed rule on
small entities. EPA has considered and addressed all of the previously
described requirements. The following is a summary of the IRFA.
The first and second requirements are discussed in Section II of
this Preamble. The third, fourth, and sixth requirements are summarized
as follows. The fifth requirement is discussed under Section VIII.A.2
of this Preamble in a subsection addressing potential interactions
between the radon rule and upcoming and existing rules affecting ground
water systems.
4. Number of Small Entities Affected
EPA estimates that 40,863 ground water systems are potentially
affected by the proposed radon rule, with 96 percent of these systems
serving less than 10,000 persons. Of the 39,420 small systems
potentially affected, EPA estimates that 1,761 (4.4 percent) small
systems will have to modify treatment (install treatment technology) to
comply with the AMCL. The proposed rule recommends that small systems
meet the 4,000 pCi/L AMCL and implement a multimedia mitigation (MMM)
program if their State does not implement a MMM program. Small systems
may also choose to comply with the MCL rather than implement an MMM
program. As Table XIV.1 indicates, water mitigation administration
costs for small systems remain the same under any State MMM program
adoption scenario. However, small systems located in States that do not
implement a MMM program must develop and implement their own MMM
program for the population they serve (unless they choose to comply
with the MCL), thus increasing their costs. Additional MMM
implementation scenarios have been analyzed in the RIA (USEPA 1999f)
which is included in the docket for this proposed rulemaking.

[[Page 59346]]

Table XIV.1.--Annual Water Mitigation and MMM Program Costs to Small
Systems
[$Millions, 1997]
------------------------------------------------------------------------
100% of states 50% of states
Cost description adopt MMM adopt MMM
------------------------------------------------------------------------
Water Mitigation Costs \1\
Total Capital Costs................. 118.5 194.1
Total Annual Costs \2\.............. 31.3 43.2
Water Mitigation Administration Costs... 5.8 5.8
Multimedia Mitigation Program Costs \3\. 0 43.3
Total Small System Costs per Year....... 37.1 92.4
------------------------------------------------------------------------
Notes:
\1\ Costs to small systems to mitigate water to the AMCL of 4,000 pCi/L.

\2\ Includes annual capital costs, monitoring costs, and operation and
maintenance costs.
\3\ Does not include the costs of testing and mitigating homes.

5. Proposed Rule Reporting Requirements for Small Systems
The proposed radon rule requires small systems to maintain records
and to report radon concentration levels at point-of-entry to the water
system's distribution system. Small systems are also required to
provide radon information in the Consumer Confidence Report, and if the
system is implementing its own MMM program, reports on progress to the
goals outlined in the system's MMM program plan. Radon monitoring and
reporting for water mitigation will be required on a quarterly basis
for at least one year, but thereafter the frequency may be reduced to
annually or once every three years depending on the level of radon
present (see Section VIII.E). Other existing information and reporting
requirements, such as Consumer Confidence Reports and (proposed) public
notification requirements, will be marginally expanded to encompass
radon along with other contaminants (see Section X). As is the case for
other contaminants, required information on system radon levels must be
provided by affected systems and is not considered to be confidential.
The professional skills necessary for preparing the reports are the
same skill level required by small systems for current reporting and
monitoring requirements.
The classes of small entities that are subject to the proposed
radon rule include public groundwater systems serving less than 10,000
people. Small systems are further classified into very very small
systems (serving 25-500 persons), very small systems (serving 501-3,300
persons, and small systems (serving 3,301-10,000 persons).
6. Significant Regulatory Alternatives and SBAR Panel Recommendations
In response to the SBAR Panel's recommendations and other small
entity concerns, EPA has included several requirements to help reduce
the impacts of the proposed radon rule on small entities. These
requirements include: (1) Recommendation of small system compliance
with the MMM/AMCL option; (2) less routine monitoring; (3) State
granting of waivers to ground water systems to reduce monitoring
frequency; and (4) encouraging and providing information about the use
of low maintenance treatment technologies. A more complete discussion
of the SBAR Panel recommendations and EPA's responses follow here. EPA
also believes small systems can in some cases reduce their economic
burden by a variety of means, including using the State revolving fund
loans to offset compliance costs. In the development of this proposed
rulemaking, EPA considered several regulatory alternatives to the
proposed requirements for small systems. The proposal includes the
regulatory expectation that they comply with the AMCL of 4,000 pCi/L
and be associated with either a state or local MM program. EPA believes
that this option will provide equivalent or greater health protection
while reducing economic burdens to small systems. For a more detailed
description of the alternatives considered in the development of the
proposed rule see the RIA (USEPA 1999f) or the discussion of regulatory
alternatives in Section XIV.C (Unfunded Mandates Reform Act).
In addition to being summarized here, the public docket for this
proposed rulemaking includes the SBAR Panel's report on the proposed
radon regulation, which outlines background information on the proposed
radon rule and the types of small entities that may be subject to the
proposed rule; a summary of EPA's outreach activities; and the comments
and recommendations of the small entity representatives (SERs) and the
Panel.
(a) Consultations. Consistent with the requirements of the RFA as
amended by SBREFA, EPA has conducted outreach directly to
representatives of small entities that may be affected by the proposed
rule. Anticipating the need to convene a SBAR Panel under Section 609
of the RFA/SBREFA, in consultation with the Small Business
Administration (SBA), EPA identified 23 representatives of small
entities that were most likely to be subject to the proposal. In April,
1998, EPA prepared an outreach document on the radon rule titled
``Information for Small Entity Representatives Regarding the Radon in
Drinking Water Rule'' (USEPA 1998b). EPA distributed this document to
the small entity representatives (SERs), as well as stakeholder meeting
discussion documents and the executive summary of the February 1994
document ``Report to the United States Congress on Radon in Drinking
Water: Multimedia Risk and Cost Assessment of Radon'' (EPA 1994a).
On May 11, 1998, EPA held a small entity conference call from
Washington DC to provide a forum for small entity input on key issues
related to the planned proposal of the radon in drinking water rule.
These issues included: (1) Issues related to the rule development, such
as radon health risks, occurrence of radon in drinking water, treatment
technologies, analytical methods, and monitoring; and (2) issues
related to the development and implementation of the multimedia
mitigation program guidelines. Thirty people participated in the
conference call, including 13 SERs from small water systems from
Arizona, California, Nebraska, New Hampshire, Utah, Washington,
Alabama, Michigan, Wyoming, and New Jersey.
Efforts to identify and incorporate small entity concerns into this
rulemaking culminated with the convening of a SBAR Panel on July 9,
1998, pursuant to Section 609 of RFA/SBREFA. The four person Panel was
headed by EPA's Small Business Advocacy Chairperson and included the
Director of the Standards and Risk Management Division within EPA's

[[Page 59347]]

Office of Ground Water and Drinking Water, the Administrator of the
Office of Information and Regulatory Affairs with the Office of
Management and Budget, and the Chief Counsel for Advocacy of the SBA.
For a 60-day period starting on the convening date, the Panel reviewed
technical background information related to this rulemaking, reviewed
comments provided by the SERs, and met on several occasions. The Panel
also conducted its own outreach to the SERs and held a conference call
on August 10, 1998 with the SERs to identify issues and explore
alternative approaches for accomplishing environmental protection goals
while minimizing impacts to small entities. Details of the Panel
process, along with summaries of the conference calls with the SERs and
the Panel's findings and recommendations, are presented in the
September 1998 document ``Final Report of the SBREFA Small Business
Advocacy Review Panel on EPA's Planned Proposed Rule for National
Primary Drinking Regulation: Radon'' (USEPA 1998c).
(b) Recommendations and Actions.--Today's notice incorporates all
of the recommendations on which the Panel reached consensus. In
particular, the Panel made a number of recommendations regarding the
MMM program guidelines, including that the guidelines be user-friendly
and flexible and provide a viable and realistic alternative to meeting
the MCL, for both States and CWSs. The Panel also agreed that provision
of information to the public and equity are important considerations in
the design of an MMM program.
In response to the Panel's recommendations and concerns heard from
other stakeholders, EPA has developed specific criteria that MMM
programs must meet to be approved by EPA. EPA believes these criteria
are simple and straightforward and provide the flexibility States and
public water systems need to develop programs to meet their different
needs and concerns. The criteria permit States, with public
participation and input, to determine their own prospective indoor
radon risk reduction goals and to design the program strategies they
determine are needed to achieve these goals. The criteria build on the
existing framework of State indoor radon programs that are already
working to get indoor radon risk reduction. EPA also believes that
equity issues can be most effectively discussed and resolved with the
public's participation and involvement in development of goals and
strategies for an MMM program. Providing customers of public water
systems with information about the health risks of radon and on the
AMCL and MMM program option will help to promote understanding of the
significant public health risks from radon in indoor air and help the
public to make informed choices. Section VI of this Preamble discusses
the MMM program in greater detail.
Following is a summary of the other Panel recommendations and EPA's
response to these recommendations, by subject area:
Occurrence: The Panel recommended that EPA continue to refine its
estimates of the number of affected wells. The occurrence section of
the preamble contains an expanded description in regard to how EPA
refined the estimates of the number of affected water supply wells (See
Section XI.C ``EPA's Most Recent Studies of Radon Levels in Ground
Water'').
Water Treatment: The Panel recommended the following: provide clear
guidance for when granular activated carbon (GAC) treatment may be
appropriate as a central or point-of-entry unit treatment technology;
consider and include in its regulatory cost estimates, to the extent
possible, the complete burden and benefits; and carefully consider
effects of radon-off- gassing from aeration towers and potential
permitting requirements in developing regulations or guidance related
to aeration.
In response to these recommendations, the treatment section of the
preamble contains an expanded description regarding conditions under
which granular activated carbon (GAC) treatment may be appropriate as a
central or point-of-entry unit treatment technology (See Section
VIII.A.3 ``Centralized GAC and Point-of-entry GAC''); the RIA and the
treatment sections of the preamble describe the components which
contribute to the regulatory economic analysis (See Section VIII.A.2
``Treatment Costs: BAT, Small Systems Compliance Technologies, and
Other Treatment''); high-end treatment cost estimates have been revised
to include scenarios where air-permitting costs are much higher than
typical cases (see Sections VIII.A.2 ``Treatment Cost Assumptions and
Methodology'' and ``Comparison of Modeled Costs with Real Costs from
Case Studies''); and information and rationale has been added to
support EPA's belief that permitting requirements from off-gassing from
aeration towers will not preclude installation of aeration treatment
(see Section VIII.A.3 ``Evaluation of Radon Off-Gas Emissions Risks'').
In addition, the Panel recommended that EPA fully consider the
relationship of the Radon in Drinking Water Rule with other rules
affecting the same small entities. In response, the treatment section
of the preamble, the Treatment and Cost Document, and the RIA have been
expanded to discuss the relationship of treatment for radon with other
drinking water rules including the Ground Water Rule, Lead and Copper
Rule, and the Disinfection By-Products Rules (see Section VIII.A.2
``Potential Interactions Between the Radon Rule and Upcoming and
Existing Rules Affecting Ground Water Systems'').
Analytical Methods and Monitoring: The Panel recommended the
following: fully consider the availability and capacity of certified
laboratories for radon analysis and consider the costs of monitoring;
consider applying the VOCs sampling method to radon to reduce the need
for additional training; reduce the frequency of monitoring after
initial determination of compliance and consider providing waivers from
monitoring requirements when a system is not at risk of exceeding the
MCL; and develop monitoring requirements that are simple and easy to
interpret to facilitate compliance by small systems.
In response, the analytical methods section of the preamble
includes discussion of the availability and capacity of certified
laboratories for radon analysis (see Section VIII.C ``Laboratory
Capacity--Practical Availability of the Methods''); and a clarification
that the radon sampling method is the same as for the volatile organic
carbons sampling method (see Section VIII.B.2 ``Sampling Collection,
Handling and Preservation''). The RIA and the preamble include more
detailed discussion of regulatory costs estimates including the
monitoring costs estimated (see Section VIII.B.2 ``Cost of Performing
Analysis''). The monitoring section proposed rule provides for a
reduced monitoring frequency to once every three years if the average
of four quarterly samples is less than 1/2 MCL/AMCL, provided that no
sample exceeds the MCL/AMCL (see Section VIII.E.4 ``Increased/decreased
monitoring requirements'' and Section 141.28(b) of the proposed rule).
Section VIII.E.5 ``Grandfathering of Data'' and Section 141.28(b) of
the proposed rule describes the allowance of grandfathered data, i.e.,
data collected after proposal of the rule, that meet specified
requirements. Section VIII.E.4 ``Increased/decreased monitoring
requirements'' of this Preamble discusses the allowance for States to
grant waivers to ground water systems to reduce the frequency of
monitoring, i.e., up to a 9 year

[[Page 59348]]

frequency. Section VIII.E, Table VIII.E.1 of this Preamble also
describes monitoring requirements to facilitate interpretation of the
requirements.
General: The Panel recommended that EPA explore options for
providing technical assistance to small entities to clearly communicate
the risks from radon in drinking water and indoor air, the rationale
supporting the regulation, and actions consumers can take to reduce
their risks. Therefore, this Preamble has been written to clarify to
the public the risks from radon in drinking water and radon in indoor
air, and the rationale supporting the proposed regulation (see Sections
I through V of this Preamble).
Areas in which Panel did not reach consensus: There were also a
number of issues discussed by the Panel on which consensus was not
reached. These included the appropriateness of the Agency's
affordability criteria for determining if affordable small system
compliance technologies are available, the appropriate level at which
to set the MCL, whether EPA should provide a ``model'' MMM program for
use by small systems in states that do not adopt state-wide MMM
programs, and whether information on the risks of radon and options for
reducing it provides ``health risk reduction benefits'' (as referenced
in the SDWA) independent of whether homes are actually mitigated or
built radon resistant. A detailed discussion of these issues is
included in the Panel report. EPA is requesting comment on some of
these issues in other parts of the preamble. To read the full
discussion of the issues on which EPA is requesting comment, see
Sections VII.A ``Requirements for Small Systems Serving 10,000 People
or Less'', VII.D ``Background on Selection of MCL and AMCL'', and VI.F
``Local CWS MMM Programs in Non-MMM States and State Role in Approval
of CWS MMM Program Plans.''

C. Unfunded Mandates Reform Act (UMRA)

Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), P.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 on 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 notification to
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.
1. Summary of UMRA Requirements
EPA has determined that this rule contains 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. Accordingly, EPA has prepared, under Section 202 of the UMRA,
a written statement addressing the following areas: (1) Authorizing
legislation; (2) cost-benefit analysis including an analysis of the
extent to which the costs to State, local, and tribal governments will
be paid for by the Federal government; (3) estimates of future
compliance costs; (4) macro-economic effects; and (5) a summary of
EPA's consultation with State, local, and tribal governments, a summary
of their concerns, and a summary of EPA's evaluation of their concerns.
A summary of this analysis follows and a more detailed description is
presented in EPA's Regulatory Impact Analysis (RIA) of the Radon Rule
(USEPA 1999f) which is included in the docket for this proposed
rulemaking.
(a) Authorizing legislation. Today's proposed rule is proposed
pursuant to Section 1412(b)(13) of the 1996 amendments to the SDWA
which requires EPA to propose and promulgate a national primary
drinking water regulation for radon, establishes a statutory deadline
of August 1999 to propose this rule, and establishes a statutory
deadline of August 2000 to promulgate this rule.
(b) Cost-benefit analysis. Section XIII.B of this preamble,
describing the Regulatory Impact Analysis (RIA) and Revised Health Risk
Reduction and Cost Analysis (HRRCA) for radon, contains a detailed
cost-benefit analysis in support of the radon rule. Today's proposed
rule is expected to have a total annualized cost of approximately $121
million with a range of potential impacts from $60.4 to $407.6 million,
depending on how many States and local PWSs adopt MMM programs and
comply with the AMCL. This total annualized cost consists of total
annual impacts on State, local, and tribal governments, in aggregate,
of approximately $53.5 million and total annual impacts on private
entities of approximately $67.6 million (Note: these estimates are
based on Scenario A which assumes 50 percent of States implement MMM
programs with the remaining 50 percent of States implementing system-
level MMM programs or complying with the MCL. Under Scenario E, total
costs are approximately $60.4 million. Total national costs of full
compliance with an MCL are approximately $407.6 million. Detailed
descriptions of the national costs and MMM scenarios are shown in
Section XIII of this preamble and Sections 9 and 10 of the RIA (USEPA
1999f).
The RIA includes both qualitative and monetized benefits for
improvements in health and safety. EPA estimates the proposed radon
rule will have annual monetized benefits of approximately $17.0 million
if the MCL were to be set at 4,000 pCi/L and $362 million if set at 300
pCi/L. The monetized health benefits of reducing radon exposures in
drinking water are attributable to the reduced incidence of fatal and
non-fatal cancers, primarily of the lung and stomach. Under baseline
assumptions (no control of radon exposure), 168 fatal cancers and 9.7
non-fatal cancers per year are associated with radon exposures through
CWSs. At a radon level of 4,000 pCi/L, an estimated 2.9 fatal cancers
and 0.2 non-fatal cancers per year are prevented. At a level 300 pCi/L,
62.0 fatal and 3.6 non-fatal cancers per year are prevented. The Agency
believes that compliance with an AMCL of 4,000 pCi/L and implementation
of a MMM program would result in health benefits equal to or greater
than those achieved by complying with the proposed MCL (300 pCi/L).

[[Page 59349]]

In addition to quantifiable benefits, EPA has identified several
potential non-quantifiable benefits associated with reducing radon
exposures in drinking water. These potential benefits are difficult to
quantify because of the uncertainty surrounding their estimation. Non-
quantifiable benefits may include any peace-of-mind benefits specific
to reduction of radon risks that may not be adequately captured in the
Value of Statistical Life (VSL) estimate. In addition, if chlorination
is added to the process of treating radon via aeration, arsenic pre-
oxidization will be facilitated. Neither chlorination nor aeration will
remove arsenic, but chlorination will facilitate conversion of Arsenic
(III) to Arsenic (V). Arsenic (V) is a less soluble form that can be
better removed by arsenic removal technologies. In terms of reducing
radon exposures in indoor air, provision of information to households
on the risks of radon in indoor air and the availability of options to
reduce exposure may be a non-quantifiable benefit that can be
attributed to some components of a MMM program. Providing such
information might allow households to make more informed choices about
the need for risk reduction given their specific circumstances and
concerns than they would have in the absence of a MMM program.
(i) State and Local Administrative Costs. States will incur a range
of administrative costs with the MCL and MMM/AMCL options in complying
with the radon rule. Administrative costs associated with water
mitigation can include costs associated with program management,
inspections, and enforcement activities. EPA estimates the total annual
costs of administrative activities for compliance with the MCL to be
approximately $2.5 million.
Additional administrative costs will be incurred by those States
who comply with the AMCL and develop an MMM program plan. In this case,
States will need to satisfy the four criteria for an acceptable MMM
program which include: (1) Involve the public in developing the MMM
program plan; (2) set quantitative State-wide goals for reducing radon
levels in indoor air; (3) submit and implement plans on existing and
new homes; and (4) develop and implement plans for tracking and
reporting results. The administrative costs will consist of the various
activities necessary to satisfy these four criteria. Because EPA is
unable to specify the number of States that will implement an MMM
program, administrative costs were estimated under two assumptions: (1)
50 percent of States (all water systems in those States) implement an
MMM program; and (2) 100 percent of States implement an MMM program,
since we expect that most States will choose this option.
If a State does not develop an MMM program plan, any local water
system may chose to meet the AMCL and prepare an MMM program plan for
State approval. Administrative costs to the State would consist
primarily of reviewing local program plans and overseeing compliance.
However, local water systems would bear administrative costs that
resemble the State costs to administer an MMM program. To estimate
costs for local water systems in these States, EPA assumed that all
local systems that exceeded 300 pCi/L but were less than 4,000 pCi/L
would choose to administer an MMM program rather than achieve the 300
pCi/L level through water mitigation. It is assumed that, on average,
water mitigation costs will exceed MMM program administrative costs for
local water systems.
EPA estimates that total annual costs of approximately $13.2
million are expected if half the States elect to administer an MMM
program and all local water systems in the remaining States undertake
MMM programs. In this case, costs to 50 percent of the States to
administer the MMM program ($2.9 million), and costs to 50 percent of
the States to approve MMM programs developed by local water systems
($7.8 million) are added to water mitigation costs ($2.5 million). In
this latter case there would also be costs to local water systems of
$45 million to develop and implement local MMM programs. This is the
total cost per year across all system sizes to develop and implement
system-level MMM programs and assumes approximately 45 percent of CWSs
will do a system-level MMM plan. The total costs across all system
sizes under Scenario E for system-level MMM programs is approximately
$5 million.
Various Federal financial assistance programs exist to help State,
local, and tribal governments comply with this rule. To fund
development and implementation of a MMM program, States have the option
of using Public Water Systems Supervision (PWSS) Program Assistance
Grant funds [SDWA Section 1443(a)(1)] and Program Management Set-Aside
funds from the Drinking Water State Revolving Fund (DWSRF) program.
Infrastructure funding to provide the equipment needed to ensure
compliance is available from the DWSRF program and may be available
from other Federal agencies, including the Housing and Urban
Development's Community Development Block Grant Program or the
Department of Agriculture's Rural Utilities Service.
EPA provides funding to States that have a primary enforcement
responsibility for their drinking water programs through the PWSS
grants program. States may use PWSS grant funds to establish and
administer new requirements under their primacy programs, including MMM
programs. PWSS grant funds may be used by a State to set-up and
administer a State MMM program.
States may also ``contract'' to other State agencies to assist in
the development or implementation of their primacy program, including
an MMM program for radon. However, States may not use grant funds to
contract to regulated entities (i.e., water systems) for MMM program
implementation.
An additional source of EPA funding to develop and implement a MMM
program is through the DWSRF program. The program awards capitalization
grants to States, which in turn use funds to provide low cost loans and
other types of assistance to eligible public water systems to assist in
financing the costs of infrastructure needed to achieve or maintain
compliance with SDWA requirements. The DWSRF program also allows a
State to set aside a portion of its capitalization grant to support
other activities that result in protection of public health and
compliance with the SDWA. The State Program Management set-aside (SDWA
Section 1452(g)(2)) allows a State to reserve up to ten percent of its
DWSRF allotment to assist in implementation of the drinking water
program. States must match expenditures under this set-aside dollar for
dollar. DWSRF State Program Management set-aside funds can be used to
fund activities to develop and run an MMM program, similar to those
eligible for funding from PWSS grant funds.
States may also use State Indoor Radon Grant (SIRG) funds to assist
States in funding their MMM programs. The Agency has determined that
activities that implement MMM activities and that meet current SIRG
eligibility requirements can be carried out with SIRG funds because the
goals of the MMM program reinforce and enhance the goals, strategies,
and priorities of the existing State indoor radon programs that rely on
funding through the SIRG program. However, expenditure of SIRG will not
be permitted to fund strictly water-related activities, such as testing
or monitoring of water by CWSs.

[[Page 59350]]

(c) Estimates of future compliance costs. To meet the requirement
in Section 202 of the UMRA, EPA analyzed future compliance costs and
possible disproportionate budgetary effects of both the MCL and MMM/
AMCL options. The Agency believes that the cost estimates, indicated
previously and discussed in more detail in Section XIII.B of today's
preamble accurately characterize future compliance costs of the
proposed rule.
(d) Macroeconomic effects. As required under UMRA Section 202, EPA
is required to estimate the potential macro-economic effects of the
regulation. These types of effects include those on productivity,
economic growth, full employment, creation of productive jobs, and
international competitiveness. Macro-economic effects tend to be
measurable in nationwide econometric models only if the economic impact
of the regulation reaches 0.25 percent to 0.5 percent of Gross Domestic
Product (GDP). In 1998, real GDP was $7,552 billion so a rule would
have to cost at least $18 billion annually to have a measurable effect.
A regulation with a smaller aggregate effect is unlikely to have any
measurable impact unless it is highly focused on a particular
geographic region or economic sector. The macro-economic effects on the
national economy from the radon rule should be negligible based on the
fact that, assuming full compliance with an MCL, the total annual costs
are approximately $43.1 million at the 4,000 pCi/L level and about
$407.6 million at the 300 pCi/L level (at a 7 percent discount rate)
and the costs are not expected to be highly focused on a particular
geographic region or industry sector.
(e) Summary of EPA's consultation with State, local, and tribal
governments and their concerns. Consistent with the intergovernmental
consultation provisions of section 204 of the UMRA and Executive Order
12875 ``Enhancing Intergovernmental Partnership,'' EPA has already
initiated consultations with the governmental entities affected by this
rule. EPA initiated consultations with governmental entities and the
private sector affected by this rulemaking through various means. This
included four stakeholder meetings, and presentations at meetings of
the American Water Works Association, the Association of State Drinking
Water Administrators, the Association of State and Territorial Health
Officials, and the Conference of Radiation Control Program Directors.
Participants in EPA's stakeholder meetings also included
representatives from National Rural Water Association, National
Association of Water Companies, Association of Metropolitan Water
Agencies, State department of environmental protection representatives,
State health department representatives, State water utility
representatives, the Inter Tribal Council of Arizona, and
representatives of other tribes. EPA also made presentations at tribal
meetings in Nevada, Alaska, and California. To address the proposed
rule's impact on small entities, the Agency convened a Small Business
Advocacy Review Panel in accordance with the Regulatory Flexibility Act
(RFA) as amended by the Small Business Regulatory Enforcement Fairness
Act (SBREFA). EPA also held two series of three conference calls with
representatives of State drinking water and State radon programs. In
addition to these consultations, EPA made presentations on the proposed
Radon Rule to the Association of California Water Agencies, the
National Association of Towns and Townships, the National League of
Cities, and the National Association of Counties. Several State
drinking water representatives also participated in AWWA's Technical
Workgroup for Radon.
The Agency also notified governmental entities and the private
sector of opportunities to provide input on the Health Risk Reduction
and Cost Analysis (HRRCA) for radon in drinking water in the Federal
Register on February 26, 1999 (64 FR 9559). The HRRCA was published six
months in advance of this proposal and illustrated preliminary cost and
benefit estimates for various MCL options under consideration for the
proposed rule. The comment period on the HRRCA ended on April 12, 1999,
and EPA received approximately 26 written comments. Of the 26 comments
received concerning the HRRCA, 42 percent were from States and 4
percent were from local governments.
The public docket for this proposed rulemaking contains meeting
summaries for EPA's four stakeholder meetings on radon in drinking
water, all comments received by the Agency, and provides details about
the nature of State, local, and tribal governments' concerns. A summary
of State, local, and tribal government concerns on this proposed
rulemaking is provided in the following section.
In order to 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 persons 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 a
brief overview on the forthcoming radon rule at the meeting. The
presentation included the health concerns associated with radon, EPA's
current position on radon in drinking water, the distinction between an
MCL and AMCL, the multimedia mitigation (MMM) program, and specific
issues for tribes. The following questions were posed to the tribal
representatives to begin discussion on radon in drinking water: (1)
Will tribal governments be interested in substituting MMM for drinking
water control; (2) what types of MMM could tribes reasonably implement;
and (3) what resources are available to fund MMM? 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.

[[Page 59351]]

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. Tribal representatives were generally supportive of
regulations which would ensure a high level of water quality, but
raised concerns over funding for regulations. With regard to the
forthcoming proposed radon rule, many tribal representatives saw the
multimedia mitigation option as highly desirable, but felt that this
option may not be adapted unless funds were made available for home
mitigation. Meeting summaries for EPA's tribal consultations are
available in the public docket for this proposed rulemaking.
(f) Nature of state, local, and tribal government concerns and how
EPA addressed these concerns. State and local governments raised
several concerns, including the high costs of the rule to small
systems; the high degree of uncertainty associated with the benefits;
the high costs of including Non-Transient Non-Community Water Systems
(NTNCWSs); and the inclusion of risks to both smokers and non-smokers
in the proposed regulation. Tribal governments raised several concerns
with the MMM program, including where the funding to mitigate homes
would come from; the number of homes that would require testing; and
the frequency of home testing.
EPA understands the State, local, and tribal government concerns
with the issues described previously. The Agency believes that the
options for small systems, proposed for public comment in this
rulemaking, will address stakeholder concerns pertaining to small
systems and will help to reduce the financial burden to these systems.
Non-Transient Non-Community Water Systems (NTNCWSs) are not subject
to this proposed rulemaking. A detailed discussion of the exposure to
radon in NTNCWSs is shown in Section XII.D of this preamble. EPA has
conducted a preliminary analysis on exposure and risks to NTNCWSs and
is soliciting public comment on this preliminary analysis. An analysis
of the potential benefits and costs of radon in drinking water for
NTNCWSs is included in the docket for this proposed rulemaking. (USEPA
1999m)
EPA has included the risks to both ever-smokers and never-smokers
in this proposed rulemaking. The Agency is basing this regulation on
the risks to the general population and is not excluding any particular
segments of the population. For a more complete discussion on the risks
of radon in drinking water and air, see Section XII of this preamble.
EPA understands tribal governments' concerns with funding for the
MMM program. To assist State, local, and tribal governments with the
implementation of an MMM program, EPA is making available Public Water
Supply Supervision (PWSS) Program Assistance Grant Funds, Drinking
Water State Revolving Fund (DWSRF) funds, and State Indoor Air Grant
(SIRG) funds. A more complete discussion of the funding available to
State, local, and tribal governments for MMM program implementation is
shown in Section XIV.C.1(b) of this preamble.
(g) Regulatory Alternatives Considered. As required under Section
205 of the UMRA, EPA considered several regulatory alternatives in
developing an MCL for radon in drinking water. In preparation for this
consideration, the Regulatory Impact Analysis and Health Risk Reduction
and Cost Analysis (HRRCA) for Radon evaluated radon levels of 100, 300,
500, 700, 1,000, 2,000, and 4,000 pCi/L.
The Regulatory Impact Analysis and HRRCA also evaluated national
costs and benefits of MMM implementation, with States choosing to
reduce radon exposure in drinking water through an Alternative Maximum
Contaminant Level (AMCL) and radon risks in indoor air through MMM
programs. Based on the National Academy of Sciences recommendations,
the AMCL level that was evaluated is 4,000 pCi/L. For further
discussion on the regulatory alternatives considered in this proposed
rulemaking, see Section XIII.B of this preamble.
EPA believes that the regulatory approaches proposed in today's
notice are the most cost-effective options for radon that achieve the
objectives of the rule, including strong public health protection. For
a complete discussion of this issue, see EPA's Regulatory Impact
Analysis and Revised HRRCA for Radon (USEPA 1999f).
2. Impacts on Small Governments
In preparation for the proposed radon rule, EPA conducted analysis
on small government impacts. This rule may significantly impact small
governments. EPA included small government officials or their
designated representatives in the rule making process. EPA conducted
four stakeholder meetings on the development of the radon rule which
gave a variety of stakeholders, including small governments, the
opportunity for timely and meaningful participation in the regulatory
development process. Groups such as the National Association of Towns
and Townships, the National League of Cities, and the National
Association of Counties participated in the proposed rulemaking
process. Through such participation and exchange, EPA notified
potentially affected small governments of requirements under
consideration and provided officials of affected small governments with
an opportunity to have meaningful and timely input into the development
of the regulatory proposal.
EPA also held a conference call on May 11, 1998, to consult
directly with representatives of small entities that may be affected by
the proposed rule. This conference call provided a forum for Small
Entity Representative (SER) input on key issues related to the proposed
radon rule. These issues included: (1) Issues related to the rule
development, such as radon health risks, occurrence of radon in
drinking water, treatment technologies, analytical methods, and
monitoring; and (2) issues related to the development and
implementation of the MMM program guidelines.
As required by SBREFA, EPA also convened a Small Business Advocacy
Review (SBAR) Panel to help further identify and incorporate small
entity concerns into this proposed rulemaking. For a sixty-day period
starting in July 1998, the Panel reviewed technical background
information related to this rulemaking, reviewed comments provided by
the SERs, and met on several occasions with EPA and on one occasion
with the SERs to identify issues and explore alternative approaches for
accomplishing environmental goals while minimizing impacts to small
entities. The SBAR final report on the proposed radon rule, which
includes a description of the SBAR Panel process and the Panel's
findings and recommendations, is available in the public docket for
this proposed rulemaking. For a more detailed discussion of the Panel
report, see Section XIV.B of this preamble.
In addition, EPA will educate, inform, and advise small systems,
including those run by small governments, about the radon rule
requirements. One of the most important components of this process is
the Small Entity Compliance Guide, required by the Small Business
Regulatory Enforcement Fairness Act of 1996 after the rule is
promulgated. This plain-English guide will explain what actions a small
entity must take to comply with the rule. Also, the Agency is
developing fact sheets that concisely describe various aspects and
requirements of the radon rule.

[[Page 59352]]

D. Paperwork Reduction Act (PRA)

The information collection requirements in this proposed rule have
been submitted for approval to the Office of Management and Budget
(OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. An
Information Collection Request (ICR) document has been prepared by EPA
(ICR, No. 1923.01) and a copy may be obtained from Sandy Farmer by mail
at OP Regulatory Information Division, U.S. Environmental Protection
Agency (2137), 401 M St., SW, Washington, DC 20460; by email at
farmer.sandy@epa.gov; or by calling (202) 260-2740. A copy may also be
downloaded off the Internet at http://www.epa.gov/icr.
Two types of information will be collected under the proposed radon
rule. First, information on individual water systems and their radon
levels will enable the States and EPA to evaluate compliance with the
applicable MCL or AMCL. This information, most of which consists of
monitoring results, corresponds to information routinely collected from
water systems for other types of drinking water contaminants. Radon
monitoring and reporting will initially be required on a quarterly
basis for at least one year, but thereafter the frequency may be
reduced to annually or once every three years depending on the level of
radon present (see Section VIII.E). Other existing information and
reporting requirements, such as Consumer Confidence Reports and
(proposed) public notification requirements, will be marginally
expanded to encompass radon along with other contaminants. As is the
case for other contaminants, required information on system radon
levels must be provided by affected systems and is not considered to be
confidential.
The second type of information relates to the MMM program, which is
EPA's recommended approach for small systems under the proposed radon
rule. Information of this type includes MMM plans prepared by States as
well as MMM plans prepared by community ground water systems in States
that do not develop a MMM plan. The proposed rule allows States to
prepare MMM plans regardless of whether they are primacy States with
respect to drinking water programs. EPA will review the MMM plans
developed by States, and States will review system-level MMM plans.
These reviews will help ensure that MMM programs are likely to achieve
meaningful reductions in human health risks from radon exposure.
Acceptable MMM plans will include a plan for the collection of data to
track the progress of the MMM program relative to goals established in
the plans (e.g., data on the number or rate of mitigated homes and the
number or rate of new homes built radon resistant). EPA will review
State-level MMM programs at least every five years, and States will
review system-level programs at least every five years. Information
related to MMM programs (i.e., the MMM plans and tracking data) is
mandatory for States that choose to implement an EPA-approved MMM
program and enforce the AMCL for radon rather than the MCL. Similarly,
information related to system-level MMM programs is required only from
systems that comply with the AMCL rather than the MCL and are in States
that do not have a MMM program in place.
EPA believes the information discussed previously, on compliance
with the MCL or AMCL and on MMM programs, is essential to achieving the
radon-related health risk reductions anticipated by EPA under the
proposed rule.
EPA has estimated the burden associated with the specific record
keeping and reporting requirements of the proposed rule in an
accompanying Information Collection Request (ICR), which is available
in the public docket for this proposed rulemaking. 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 ways 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.
EPA has estimated a range of administrative costs for the proposed
rule. These costs do not include testing and mitigating water or
testing and mitigating households in the MMM program. The PRA requires
that average annual cost and labor for administrative costs be
calculated over a three-year period. These costs are presented next.
However, because the full implementation of the proposed rule does not
occur until later years, average annual cost and labor for a 20-year
period are also presented. These 20-year average annual costs are
presented by scenarios defined by the proportions of systems that elect
to develop system-level MMM programs and the proportions of states that
elect to implement state-wide MMM programs. These scenarios are
described in detail in Section XIII.G and Section 9 of the RIA (USEPA
1999f). Based on these analyses, EPA's burden estimates for the
proposed rule, in both costs and hours, are as follows:
Administrative costs to community groundwater systems for
mitigation-related activities are estimated to be $14.6 million per
year ($357 per system) or 267,625 hours, distributed by system size as
shown in Table XIV.2. All 40,863 community groundwater systems will
bear these costs under all scenarios evaluated.
In the first three years of the rule, there are no
administrative costs to community groundwater systems for MMM program
activities.

Table XIV.2.--Administrative Costs to Community Water Systems Associated
With Water Mitigation and System-Level MMM Programs (Excluding MMM
Testing and Mitigation)
------------------------------------------------------------------------
Administrative
Administrative costs of
System size (customers served) costs of water system-level
mitigation ($ MMM programs
per year) ($ per year)
------------------------------------------------------------------------
VVS (25-100)............................ 4,485,485 0
VVS (101-500)........................... 4,958,735 0
VS (501-3,300).......................... 3,430,387 0
S (3,301-10,000)........................ 848,487 0
M (10,001-100K)......................... 491,944 0

[[Page 59353]]

L (>100K)............................... 23,579 0
-------------------------------
Total For All Systems........... 14,598,617 0
------------------------------------------------------------------------

Administrative costs to States for water mitigation-
related activities are to be approximately $3 million per year (Table
XIV.3) and 119,625 hours, or approximately $65,400 per year per state
and 2,600 hours per year per state. Forty-six states bear these costs
under all scenarios.
Table XIV.3 presents the costs if 100 percent of all states were to
incur the specific administrative costs listed. However, no state will
bear 100 percent of state-wide MMM program costs and 100 percent of
system-level MMM program costs. These costs will be borne in an inverse
relationship; e.g., 95 percent of the states will bear administrative
costs associated with state-wide MMM programs and 5 percent of states
will bear administrative costs associated with system-level MMM
programs.

Table XIV.3.--State Administrative Costs for Water Mitigation and MMM
Programs
------------------------------------------------------------------------
($ per
year)
------------------------------------------------------------------------
Water Mitigation........................................... 3,009,713
State-Wide MMM Programs.................................... 6,346
System-Level MMM Programs.................................. 5,909
Total State Administrative Costs....................... 3,021,968
------------------------------------------------------------------------

State administrative costs associated with state-wide MMM
programs are estimated up to $6,300 per year and up to 140 hours per
year for the first three years of the rule.
State administrative costs to review system-level MMM
programs and related activities are estimated up to $5,900 per year and
up to 123 hours per year for the first three years of the rule.
The total State administrative costs (water mitigation,
state-wide, and system-level MMM programs) are estimated up to
approximately $3 million per year and 119,887 hours per year.
Because much of the activity required under the proposed rule
occurs in later years, this analysis presents average administrative
costs borne by systems and states over a 20 year period. Again, these
costs do not include water testing and mitigation or testing and
mitigating households in MMM programs. In addition, these costs are
presented by scenarios that are defined by the proportions of systems
that elect to develop system-level MMM programs and the proportions of
states that elect to implement state-wide MMM programs.
Administrative costs to community groundwater systems for
mitigation-related activities are estimated to be $8.6 million per year
($211 per system) or 145,547 hours per year, distributed by system size
as shown in Table XIV.4. All 40,863 community groundwater systems will
bear these costs under all scenarios evaluated.
Under Scenario A, administrative costs to community
groundwater systems for MMM program activities are approximately $45.1
million per year ($2,452 per system) or 174,000 hours per year for the
18,388 systems (45 percent of all community groundwater systems) that
develop and file an MMM plan. The costs are distributed across the
system size categories as shown in Table XIV.4. Under Scenario E,
administrative costs to systems are $5.0 million per year or 19,333
hours per year. The per-system cost is the same as Scenario A, but only
five percent of systems (2,042) bear these costs.

Table XIV.4.--Administrative Costs to Community Water Systems Associated With Water Mitigation and System-Level
MMM Programs
[Excluding MMM Testing and Mitigation]
----------------------------------------------------------------------------------------------------------------
Administrative Administrative
Administrative costs of costs of
costs of water system-level system-level
System size (customers served) mitigation ($ MMM programs MMM programs
per year) under scenario under scenario
A ($ per year E ($ per year
----------------------------------------------------------------------------------------------------------------
VVS (25-100).................................................... 2,857,190 14,978,142 1,664,238
VVS (101-500)................................................... 2,923,970 15,328,217 1,703,135
VS (501-3,300).................................................. 2,022,764 10,603,857 1,178,206
S (3,301-10,000)................................................ 500,319 2,622,804 291,423
M (10,001-100K)................................................. 290,080 1,520,674 168,964
L (>100K)....................................................... 13,904 72,886 8,097
-----------------------------------------------
Total for All Systems................................... 8,608,226 45,126,581 5,014,065
----------------------------------------------------------------------------------------------------------------

[[Page 59354]]

Total administrative costs to community water systems
(water mitigation plus MMM programs) range from $11 million per year
under Scenario E to $51.2 million under Scenario A or 165,000 hours
under Scenario E to 320,000 hours under Scenario A. The costs are
distributed across the various system sizes as shown in Table XIV.5.

Table XIV.5.--Total Administrative Costs Water Mitigation and MMM
Programs to Community Groundwater Systems
------------------------------------------------------------------------
Total Total
administrative administrative
System size (customers served) costs under costs under
scenario A ($ scenario E ($
per year) per year)
------------------------------------------------------------------------
VVS (25-100)............................ 16,990,791 3,676,887
VVS (101-500)........................... 17,387,906 3,762,824
VS (501-3,300).......................... 11,238,829 1,813,178
S (3,001-10,000)........................ 3,412,697 1,081,316
M (10,001-100,000)...................... 1,873,106 521,396
L (100,000)............................. 256,893 192,105
-------------------------------
Total for All Systems........... 51,160,223 11,047,707
------------------------------------------------------------------------

Administrative costs to States for water mitigation-
related activities are estimated to be approximately $2.5 million per
year (Table XIV.6) or approximately $53,900 per year per state. Total
state burden is approximately 100,000 hours per year. Forty-six states
bear these costs under all scenarios.

Table XIV.6.--State Administrative Costs for Water Mitigation and MMM
Programs
[$ per year]
------------------------------------------------------------------------
Scenario A Scenario E
------------------------------------------------------------------------
Water Mitigation........................ 2,477,299 2,477,299
State-Wide MMM Programs................. 2,926,691 5,560,713
System-Level MMM Programs............... 7,830,995 870,111
-------------------------------
Total State Administrative Costs 13,234,985 8,908,123
------------------------------------------------------------------------

State administrative costs associated with state-wide MMM
programs are estimated to be $2.9 million dollars ($127,200 per state
across 23 states) or 123,000 hours per year under Scenario A. Under
Scenario E, estimated state administrative costs of state-level MMM
programs are estimated to be $5.6 million (again $126,400 per state,
but under this scenario, 44 states bear the costs) or 233,000 hours per
year for all 44 states.
State administrative costs to review system-level MMM
programs and related activities are estimated to be $7.8 million per
year or 316,410 hours per year under Scenario A and approximately
$870,000 per year or 35,157 hours per year under Scenario E. In both
cases the cost per state is approximately $371,000 per year, with 21
states affected under Scenario A and two states affected under Scenario
E.
The total State administrative costs (water mitigation,
state-wide, and system-level MMM programs) are estimated to be $13.2
million per year or 538,845 hours per year under Scenario A and $8.9
million per year or 367,878 hours per year under Scenario E.
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.
Comments are requested on the Agency's need for this information,
the accuracy of the provided burden estimates, and any suggested
methods for minimizing respondent burden, including through the use of
automated collection techniques. Send comments on the ICR to the
Director, OP Regulatory Information Division, U.S. Environmental
Protection Agency (2137), 401 M St., SW., Washington, DC 20460 and to
the Office of Management and Budget, 725 17th St., NW., Washington, DC
20503, marked ``Attention: Desk Officer for EPA''. Include the ICR
number (1923.01) in any correspondence. Since OMB is required to make a
decision concerning the ICR between 30 and 60 days after November 2,
1999, a comment to OMB is best assured of having its full effect if OMB
receives it by December 2, 1999. The final rule will respond to any OMB
or public comments on the information collection requirements contained
in this proposal.

E. National Technology Transfer and Advancement Act (NTTAA)

Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (``NTTAA''), Public Law 104-113, Sec. 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., materials specifications, test methods,
sampling procedures, and business practices) that are developed or
adopted by voluntary consensus standard bodies. The NTTAA directs EPA
to provide Congress, through OMB, explanations when the Agency decides
not to use available and applicable voluntary consensus standards.
EPA's process for selecting the analytical test methods is
consistent with Section 12(d) of the NTTAA. EPA performed literature
searches to identify analytical methods from industry, academia,
voluntary consensus standard bodies, and other parties that could be

[[Page 59355]]

used to measure radon in drinking water.
This proposed rulemaking involves technical standards. EPA proposes
to use Standard Method 7500-Rn, which is specific for radon 222 (radon)
in drinking water, for both the MCL and AMCL for radon in drinking
water. This method meets the objectives of the rule because it
accurately and reliably detects radon in drinking water below 100 pCi/
L. Standard Method 7500-Rn was approved by the Standard Methods
Committee in 1996 and is described in the ``Standard Methods for the
Examination of Water and Wastewater (19th Edition Supplement)'' which
was prepared and published jointly by the American Public Health
Association, American Water Works Association, and Water Environment
Federation. Additional information on this method is shown in Section
VIII.B.2 of today's preamble.
EPA is also proposing the use of the American Society for Testing
and Materials (ASTM) Standard Test Method for Radon in Drinking Water
(designation: D5072-92) for the AMCL for radon in drinking water. This
method is specific for radon in drinking water, but has been shown to
accurately and reliably detect radon only at concentrations above 1,500
pCi/L and thus is only useful for the AMCL. ASTM's Standard Test Method
for Radon in Drinking Water was adopted by ASTM in 1992 and is
described in the Annual Book of ASTM Standards. Additional information
on this method is shown in Section VIII.B.2 of this preamble.
As discussed in Section VIII.B (Analytical Methods) of this
preamble, EPA is in the process of adopting the Performance-Based
Measurement System (PBMS) to allow greater flexibility in compliance
monitoring for this proposed rule and for future rules. For further
information on PBMS, see Section VIII.D.
EPA welcomes comments on this aspect of the proposed rulemaking
and, specifically, invites the public to identify potentially-
applicable voluntary consensus standards and to explain why such
standards should be used in this regulation.

F. Executive Order 12898: Environmental Justice

Executive Order 12898 ``Federal Actions To Address
EnviroPopulations 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 address various 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 March 12, 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 regulation. A meeting summary for the March
12, 1998, stakeholder meeting is available in the public docket for
this proposed rulemaking.
Stakeholders have raised concerns that this action may have a
disproportionate impact on low-income and minority populations. The
rule framework and in particular, the MMM program coupled with a 4,000
pCi/L AMCL, were discussed with EJ stakeholders at the March 12, 1998,
meeting. Key issues of concern with the MMM/AMCL approach included: (1)
The potential for an uneven distribution of benefits across water
systems and society; (2) the cost of air remediation to apartment
dwellers; and (3) the concern that the approach could provide water
systems and State governments a ``loophole'' through which they could
escape the responsibility of providing appropriate protection from
radon exposures.
The Agency considered equity-related issues concerning the
potential impacts of MMM program implementation. There is no factual
basis to indicate that minority and low income or other communities are
more or less exposed to radon in drinking water than the general
public. However, some stakeholders expressed more general concerns
about equity in radon risk reduction that could arise from the MMM/AMCL
framework outlined in SDWA. One concern is the potential for an uneven
distribution of risk reduction benefits across water systems and
society. Under the proposed framework for the rule, customers of CWSs
complying with the AMCL could be exposed to a higher level of radon in
drinking water than if the MCL were implemented, though this level
would not be higher than the background concentration of radon in
ambient air. However, these CWS customers could also save the cost,
through lower water rates, of installing treatment technology to comply
with the MCL. Under the proposed regulation, CWSs and their customers
have the option of complying with either the AMCL (associated with a
State or local MMM program) or the MCL.
EPA believes it is important that these issues and choices be
considered in an open public process as part of the development of MMM
program plans. Therefore, EPA has incorporated requirements into the
proposed rule that provide a framework for consideration of equity
concerns with the MMM/AMCL. The proposed rule includes requirements for
public participation in the development of MMM program plans, as well
as for notice and opportunity for public comment. EPA believes that the
requirement for public participation will result in State and CWS
program plans that reflect and meet their different constituents needs
and concerns and that equity issues can be most effectively dealt with
at the State and local levels with the participation of the public. In
developing their MMM program plans, States and CWSs are required to
document and consider all significant issues and concerns raised by the
public. EPA expects and strongly recommends that States and CWSs pay
particular attention to addressing any equity concerns that may be
raised during the public participation process. In addition, EPA
believes that providing CWS customers with information about the health
risks of radon and on the

[[Page 59356]]

AMCL and MMM program option will help to promote understanding of the
health risks of radon in indoor air, as well as in drinking water, and
help the public to make informed choices. To this end, EPA is requiring
CWSs to alert consumers to the MMM approach in their State in consumer
confidence reports issued between publication of the final radon rule
and the compliance dates for implementation of MMM programs. This will
include information about radon in indoor air and drinking water and
where consumers can get additional information.
The proposed requirements include the following: (1) A description
of processes the State used to provide for public participation in the
development of its MMM program plan; (2) a description of the nature
and extent of public participation that occurred, including a list of
groups and organizations that participated; (3) a summary describing
the recommendations, issues, and concerns arising from the public
participation process and how these were considered in developing the
State's MMM program plan; (4) a description of how the State made
information available to the public to support informed public
participation, including information on the State's existing indoor
radon program activities and radon risk reductions achieved, and on
options considered for the MMM program plan along with any analyses
supporting the development of such options; and (5) the State must
provide notice and opportunity for public comment on the plan prior to
submitting it to EPA.
The public is invited to comment on this aspect of the proposed
rulemaking and, specifically, to recommend additional methods to
address EJ concerns with the MMM/AMCL approach for treating radon in
drinking water.

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) Is determined to be ``economically significant''
as defined under E.O. 12866, and (2) 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
both 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 proposed rule is not subject to the Executive Order because
the Agency does not have reason to believe the environmental health
risks or safety risks addressed by this action present a
disproportionate risk to children. Based on the risk assessment for
radon in drinking water developed by the NAS, children were not
identified as being disproportionately impacted by radon. The Committee
on Risk Assessment of Exposure to Radon in Drinking Water that
conducted the National Research Council Risk Assessment of Radon in
Drinking Water Study (NAS 1999b) concluded, except for the lung cancer
risk to smokers, there is insufficient scientific information to permit
quantitative evaluation of radon risks to susceptible subpopulations
such as infants, children, pregnant women, elderly, and seriously ill
persons.
The National Academy of Sciences Committee on the Biological
Effects of Ionizing Radiation (BEIR VI) (NAS 1999a) noted that there is
only one study (tin miners in China) that provides data on whether
risks from radon progeny are different for children, adolescents, and
adults. Based on this study, the committee concluded that there was no
clear indication of an effect of age at exposure, and the committee
made no adjustments in the model for exposures received at early ages
(NAS 1999a). Nonetheless, we evaluated the environmental health or
safety effects of radon in drinking water on children. The results of
this evaluation are contained in Section XII of this preamble. Copies
of the documents used to evaluate the environmental health or safety
effects of radon in drinking water on children, including the NAS
Reports, have been placed in the public docket for this proposed
rulemaking.
The public is invited to submit or identify peer-reviewed studies
and data, of which EPA may not be aware, that assessed results of early
life exposure to radon in drinking water.

H. Executive Orders on Federalism

Under Executive Order 12875, ``Enhancing the Intergovernmental
Partnership,'' 58 FR 58093 (October 28, 1993) EPA may not issue a
regulation that is not required by statute and that creates a mandate
upon State, local, or tribal government, unless the Federal government
provides the funds necessary to pay the direct compliance costs
incurred by those governments, or EPA consults with those governments.
If EPA complies by consulting, E.O. 12875 requires EPA to provide to
the Office of Management and Budget a description of the extent of
EPA's prior consultation with representatives of affected State, local,
and tribal governments, the nature of their concerns, any written
communications from the governments, and a statement supporting the
need to issue the regulation. In addition, E.O. 12875 requires EPA to
develop an effective process permitting elected officials and other
representatives of State, local, and tribal governments ``to provide
meaningful and timely input in the development of regulatory proposals
containing significant unfunded mandates.''
EPA has concluded that this rule will create a mandate on State,
local, and tribal governments and the Federal government will not
provide the funds necessary to pay the direct costs incurred by State,
local, and tribal governments in complying with the mandate. In
developing this rule, EPA consulted with State, local, and tribal
governments to enable them to provide meaningful and timely input in
the development of this rule.
As described in Section XIV.C.1.e, EPA held extensive meetings with
a variety of State and local representatives, who provided meaningful
and timely input in the development of the proposed rule. Summaries of
the meetings have been included in the public docket for this proposed
rulemaking. See Sections XIV.C.1.e and XIV.C.1.f for summaries of the
extent of EPA's consultation with State, local, and tribal governments;
the nature of the governments' concerns; and EPA's position supporting
the need to issue this rule.
On August 4, 1999, President Clinton issued a new executive order
on federalism, Executive Order 13132 [64 FR 43255 (August 10, 1999)],
which will take effect on November 2, 1999. In the interim, the current
Executive Order 12612 [52 FR 41685 (October 30, 1987)], on federalism
still applies. This rule will not have a substantial direct effect on
States, on the relationship between the national government and the
States, or on the distribution of power and responsibilities among
various levels of government, as specified in Executive Order 12612.
``This proposed rule establishes a National Primary Drinking Water
Regulation (NPDWR) for the control of radon. This regulation is
required by section 1412(b)(13) of the Safe Drinking Water Act, as
amended. EPA conducted extensive discussions with States and local
governments in developing this proposal, and significant flexibility is
provided in implementing these regulations.''

[[Page 59357]]

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

Under Executive Order 13084, ``Consultation and Coordination with
Indian Tribal Governments,'' 63 FR 27655 (May 19, 1998) EPA may not
issue a regulation that is not required by statute, that significantly
or uniquely affects the communities of Indian tribal governments, and
that 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 EPA
consults with those governments. If EPA complies by consulting, E.O.
13084 requires EPA to provide 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, E.O. 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 has concluded that this rule will significantly or uniquely
affect communities of Indian tribal governments. It will impose
substantial direct compliance costs on such communities, and the
Federal government will not provide the funds necessary to pay the
direct costs incurred by the tribal governments in complying with the
rule. In developing this rule, EPA consulted with representatives of
tribal governments pursuant to both E.O. 12875 and E.O. 13084.
Summaries of the meetings have been included in the public docket for
this proposed rulemaking. EPA's consultation, the nature of the
governments' concerns, and EPA's position supporting the need for this
rule are discussed in Section XIV.C.2 of this preamble.

J. Request for Comments on Use of Plain Language

Executive Order 12866 and the President's memorandum of June 1,
1998, require each agency to write all rules in plain language. We
invite your comments on how to make this proposed rule easier to
understand. For example:
Have we organized the material to suit your needs?
Are the requirements in the rule clearly stated?
Does the rule contain technical language or jargon that
isn't clear?
Would a different format (grouping and order of sections,
use of headings, paragraphing) make the rule easier to understand?
Would more (but shorter) sections be better?
Could we improve clarity by adding tables, lists, or
diagrams?
What else could we do to make the rule easier to
understand?

Stakeholder Involvement

XV. How Has the EPA Provided Information to Stakeholders in
Development of This NPRM?

A. Office of Ground Water and Drinking Water Website

EPA's Office of Ground Water and Drinking Water maintains a website
on radon at the following address: http://www.epa.gov/safewater/
radon.html. Documents are placed on the website for public access.

B. Public Meetings

EPA has consulted with a broad range of stakeholders and technical
experts. Participants in a series of stakeholder meetings held in 1997
and 1998 included representatives of public water systems, State
drinking water and indoor air programs, tribal water utilities and
governments, environmental and public health groups, and other Federal
agencies. EPA convened an expert panel in Denver in November, 1997, to
review treatment technology costing approaches. The panel made a number
of recommendations for modification to EPA cost estimating protocols
that have been incorporated into the radon cost estimates. EPA also
consulted with a subgroup of the National Drinking Water Advisory
Council (NDWAC) on evaluating the benefits of drinking water
regulations. The NDWAC was formed in accordance with the Federal
Advisory Committee Act (FACA) to assist and advise EPA. A variety of
stakeholders participated in the NDWAC benefits working group,
including utility company staff, environmentalists, health
professionals, State water program staff, a local elected official,
economists, and members of the general public.
EPA conducted one-day public meetings in Washington, D.C. on June
26, 1997; in San Francisco, California on September 2, 1997; and in
Boston, Massachusetts on October 30, 1997, to discuss its plans for
developing a proposed NPDWR for radon-222. EPA presented information on
issues related to developing the proposed NPDWR and solicited
stakeholder comments at each meeting. EPA also held a series of
conference calls in 1998 and 1999 with State drinking water and indoor
air programs, to discuss issues related to developing guidelines for
multiedia mitigation programs. EPA also held a public meeting in
Washington, DC. on March 16, 1999, to discuss the HRRCA published on
February 26, 1999, and the multimedia mitigation framework.

C. Small Entity Outreach

EPA has conducted outreach directly to representatives of small
entities that may be affected by the proposed rule, as part of SBREFA.
A full discussion of the small entity outreach is in Section XIV.B.6
``Significant Regulatory Alternatives and SBAR Panel Recommendations.''

D. Environmental Justice Initiatives

In order to uphold Executive Order 12898, ``Federal Actions to
Address Environmental Justice in Minority Populations and Low-Income
Populations,'' EPA's Office of Ground Water and Drinking Water convened
a public meeting in Washington, DC in March 1998 to discuss ways to
involve minority, low-income, and other sensitive subgroups in the
stakeholder process and to obtain input on the proposed radon rule. The
meeting was held in a video-conference format linking EPA Regions I
through IX to involve as many stakeholders as possible. EPA has taken
the concerns and issues raised by the environmental justice community
into account while setting the MCL, MCLG, and AMCL for radon. For more
information on the March 1998 environmental justice meeting, and on EPA
proposals to address concerns of stakeholders, see Section XIV.F of
this Preamble.

E. AWWA Radon Technical Work Group

The American Water Works Association (AWWA) convened a ``Radon
Technical Work Group,'' in 1998 that provided technical input on EPA's
update of technical analyses (occurrence, analytical methods, and
treatment technology), and discussed conceptual issues related to
developing guidelines for multimedia mitigation programs. Members of
the Radon Technical Work Group included representatives from State
drinking water and indoor air programs, public water systems, drinking
water testing laboratories, environmental groups and the U.S.
Geological Survey.

[[Page 59358]]

Background

XVI. How Does EPA Develop Regulations to Protect Drinking Water?

A. Setting Maximum Contaminant Level Goal and Maximum Contaminant Level

EPA sets an MCLG and MCL or treatment technology for each regulated
contaminant. The MCLG is based on analysis of health effects of the
contaminant. Based on the carcinogenicity of ionizing radiation, and
the NAS' current recommendation for a linear, non-threshold
relationship between exposure to radon and cancer in humans (NAS
1999a), the Agency is proposing an MCLG of zero for radon in drinking
water.
A drinking water MCL applies to finished (treated) drinking water
as supplied to customers. The SDWA generally requires that EPA set the
MCL for each contaminant as close as feasible to the corresponding
MCLG, based on available technology and taking costs into account. For
example, if the analytical methods will only allow a relatively
confident measure of a contaminant at a certain level, then the MCL
cannot practically be set below that level. In addition, the cost of
water treatment technologies is considered. If treatment capabilities
are limited then the MCL must be set at a level that is found to be
feasible. The MCL set by EPA must be protective of public health.
The 1996 amendments to SDWA require the Administrator to do a cost-
benefit analysis of the MCLs under consideration and to make a
determination as to whether the benefits of an MCL under consideration
justify the costs (1412(b)(3)(C)). The Administrator may set an MCL at
a level less stringent than the feasible level if he/she finds that the
benefits of the feasible MCL do not justify the costs (1412(b)(6)(A)).
There are certain exceptions to the use of this authority
(1412(b)(6)(B) and (C)).

B. Identifying Best Available Treatment Technology

As discussed also in Section VIII of this preamble, EPA identifies
one or more water treatment technologies (i.e., best available
treatment (BAT)) found to be effective in removing the contaminant from
drinking water and capable of meeting the MCL. There are a number of
physical, chemical, and other means used by such treatment technologies
for removing the contaminant, or in some cases destroying the
contaminant or otherwise changing the contaminant's composition. In
assessing potential BATs, EPA examines removal efficiency, cost to
purchase and maintain, compatibility with other processes, and other
factors. Most of the information cited by EPA in this context is
gleaned from technical literature, including research studies covering
pilot or full scale treatments. If some of the treatments identified
are found to be most efficient, practical and economical, EPA places
these on the BAT list and on occasion may provide guidance on other
treatments that may have certain limitations.

C. Identifying Affordable Treatment Technologies for Small Systems

The 1996 Amendments to the SDWA directed EPA to identify treatment
technologies that are affordable for small water systems. EPA is
charged with identifying affordable treatments for three small system
population categories: systems serving from 25 to 500, 501 to 3,300,
and 3,301 to 10,000 persons. A designated ``compliance technology'' for
these small systems may be a technology that is affordable and that
achieves compliance with the MCL or a treatment technique requirement.
Possible compliance technologies may include packaged or modular
systems, and point-of-entry (POE) or point-of-use (POU) type treatment
units. As with BAT designations, the compliance technology(ies)
selected by EPA must be based upon available information from technical
journals and/or qualified research studies.
EPA must also identify affordable ``variance technologies'' which
are to be installed by a public water system after the system has
applied to the responsible primacy agency for a variance, i.e., a
``small system variance.'' This variance applies only to systems
serving fewer than 10,000 people. It also applies only in cases where
an affordable technology is not available to achieve compliance with an
MCL (or treatment technique requirement) yet still will be protective
of public health. One of the requirements for systems that have
obtained a variance is to install and maintain the variance technology
in accordance with the listing by EPA, which may be specific to system
size and/or dependent upon source water quality. A small system
variance may only be obtained if compliance with the MCL through
alternate source, treatment, or restructuring options are deemed not to
be affordable for that system.
Small system variances are not available to meet MCL or treatment
technique requirements promulgated prior to 1986, nor for regulations
addressing microbiological contamination of water.

D. Requirements for Monitoring, Quality Control, and Record Keeping

Water systems are responsible for conducting monitoring of drinking
water to ensure that it meets all drinking water standards. To do this,
water systems and States use analytical methods set out in EPA
regulations.
EPA is responsible for evaluating analytical methods developed for
drinking water and approves those methods that it determines meet
Agency requirements. Laboratories analyzing drinking water compliance
samples must be certified by the EPA or the State.
Whether addressing regulated or unregulated contaminants, EPA
establishes requirements as to how often water systems must monitor for
the presence of the subject contaminant. Water systems serving larger
populations generally must conduct more monitoring (temporally and
spatially) because there is a greater potential human health impact of
any violation, and because of the physical extent of larger water
systems (e.g., miles of pipeline carrying water). Small water systems
can receive variances or exemptions from monitoring in limited
circumstances. In addition, under certain conditions, a State may have
the option to modify monitoring requirements on an interim or a
permanent basis for regulated contaminants, with a few exceptions.
States may use this flexibility to reduce monitoring requirements for
systems with low risk of incurring a violation.

E. Requirements for Water Systems to Notify Customers of Test Results
if Not in Compliance

Each owner or operator of a public water system must notify
customers if the system has failed to comply with an MCL or treatment
technique requirement, or a testing procedure required by EPA
regulation. A system must notify its customers if the system is subject
to a variance (due to an inability to comply with an MCL).
The form of this notification must be readily understood and
delivered via mail or direct delivery, through an annual report, or in
the first water billing cycle following such a drinking water
violation. The notification must also contain important information
about the contaminant so that consumers will be aware of any particular
hazards involved; the notification may indicate whether water can/
cannot be consumed or used for bathing, whether boiling drinking water

[[Page 59359]]

will make it safe; or whether storing water before use may be
advisable.

F. Approval of State Drinking Water Programs to Enforce Federal
Regulations

Section 1413 of the SDWA sets requirements that a State or eligible
Indian tribe must meet in order 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; (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; (5) adopting and being capable
of implementing an adequate plan for the provision of safe drinking
water under emergency situations, and (6) adopting authority for
administrative penalties.
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 40 CFR 142.12 to
include these regulation-specific provisions in an application for
approval of their program revisions.

XVII. Important Technical Terms

Adsorption: In the case of the water/solid interface, the
accumulation of a dissolved chemical species at the interface between a
solid material (e.g., granular activated carbon) and water.
Alpha particle: A radioactivity decay product consisting of the
charged helium-4 nucleus (two protons and two neutrons with a positive
ionic charge of two, +2). Alpha particles are relatively heavy (8000
times as heavy as the beta particle) and are quickly absorbed by
surrounding matter. The properties of alpha particles are such that
they are only a health hazard if the emitter is in contact with living
tissue. When outside the body, they do not penetrate the skin and are
stopped by a few centimeters of air. However, when inside the body
(breathed in or ingested), the alpha particle may ionize molecules
within cells or may form ``free radicals'' (an atom or chemical group
that contains an unpaired electron and which is very chemically
reactive), either of which may result in the disruption of normal
cellular metabolism and produce changes that affect cell replication
which may induce cancerous cellular growth.
Bq (becquerel): An alternative unit of radioactivity is the Bq,
which is equal to 1 disintegration per second. One pCi is equal to
0.037 Bq, and one Bq is equal to 27 pCi.
cpm/dpm: Counts per minute divided by radioactive disintegrations
per minute; counting efficiency as determined by the counts per minute
detected relative to the predicted disintegrations per minute in a
well-characterized standard.
Half-life: The time required for one-half of a population of
radioactive isotopes to decay; in the case of radioactive contaminants
dissolved in water, it is the time for the concentration of the
radioactive contaminant to decrease by a factor of two due to
radioactive decay.
Heterotrophic Plate Count: A laboratory procedure for estimating
the total bacterial count in a water sample (or ``bacterial density'').
Individual Risk: The risk to a person from exposure to radon in
water is calculated by multiplying the concentration of radon in the
water (pCi/L) by the unit risk factor (risk per pCi/L) for the exposure
pathway of concern (ingestion, inhalation).
Isotopes: Two or more forms of an atomic element having the same
number of protons, but differing in the number of neutrons. Some
isotopes are stable (not radioactive) and some are radioactive,
depending upon the ratio of neutrons and protons.
Monte Carlo Analysis:: Method of approximating a distribution of
model solutions by sampling from simulated ``random picks'' from
distributions of model input values.
pCi (picocurie):: a unit of radioactivity equal to 0.037
radioactive disintegrations per second.
Percentile: For any set of observations, the ``pth percentile
value'' is the value such that p% of the observations fall below the
pth percentile value and (100-p)% fall above it.
pH: Numerical scale for measuring the relative acidity or basicity
of an aqueous solution; values less than 7 are acidic (becoming
increasingly so as they decrease) and above 7 are basic (becoming
increasing so as they increase).
Radioactivity: The spontaneous disintegration of unstable atomic
nuclei (central core of an atom), resulting in the formation of new
atomic elements (daughter products), which may or may not themselves be
radioactive, and the discharge of alpha particles, beta particles, or
photons (other decay particles are known, but their parent isotopes do
not occur in drinking water).
Removal efficiency: A measure of the ability of a particular water
treatment process to remove a contaminant of interest; defined as the
concentration of the contaminant in the treated water (effluent)
divided by the concentration of the contaminant in the source water
(influent).
WL (working level): Any combination of radioactive chemicals that
result in an emission of 1.3 x 10⁵ MeV of alpha particle
energy. One WL is approximately the total amount of energy released by
the short-lived progeny in equilibrium with 100 pCi of radon.
Working Level Month (WLM): 170 hours of exposure to one Working
Level (WL) of radon progeny.
Unit Risk: The risk from lifetime exposure, via the inhalation and
ingestion exposure routes, to water containing an unit concentration (1
pCi/L) of radon.

XVIII. References

American Society for Testing and Materials. 1992 Annual Book of ASTM
Standards, Standard Test Method for Radon in Drinking Water.
Designation: D 5072-92. Vol. 11.01, Philadelphia, PA. [1992] [ASTM
1992]
American Water Works Association. Water:/Stats: The Water Utility
Database, 1996 Survey: Water Quality, Denver, CO. [1997] [AWWA 1997]
American Water Works Association. Existing Volatile Organic Chemical
Treatment Installations: Design, Operations, and Costs, Report of
the Organic Contaminants Control Committee. Denver, CO. [1991] [AWWA
1990]
American Water Works Association Research Foundation. Assessment of
GAC Absorption for Radon Removal, Denver, CO. [November 1998]
[AWWARF 1998a]
American Water Works Association Research Foundation. Critical
Assessment of Radon Removal Systems for Drinking Water Supplies,
Denver, CO. [December 1998] [AWWARF 1998b]
California Department of Health Services. Letter with Attachment
Regarding Radon Sampling Protocol from Jane Jensen of the CA DHS
Environmental Laboratory Accreditation Program to William Labiosa,
USEPA, Office of Ground Water and Drinking Water, [September 3,
1997] [CA DHS 1997]
Centers for Disease Control. Morbidity and Mortality Weekly Report,
Cigarette smoking among adults--United States 1993. [1995] [CDC
1995]
Cornwell, D.A. Air Stripping and Aeration. In Water Quality and
Treatment, 4th Edition, F. Pointius, ed. American Water Works
Association. McGraw-Hill, Inc. New York, NY. 1990. [Cornwell 1990]
Davis, R.M.S. and Watson, J.E. Jr. The Influence of Radium
Concentration in

[[Page 59360]]

Surrounding Rock on Radon Concentration in Ground Water, University
of North Carolina, Chapel Hill. [March 13, 1989] [Davis and Watson
1989]
Dell'Orco M.J., Chadik, P., Bitton, G., and Neumann, R. Sulfide-
Oxidizing Bacteria: Their Role During Air-Stripping. J. of the
American Water Works Association. (90:107-115). [October 1998]
[Dell'Orco et al. 1998]
Dihm, H. and Carr, F.R. Air Stripping Tower Fouling Control for a
Groundwater Treatment System in Florida. In Air Stripping of
Volatile Organic Contaminant Removal. AWWA. Denver, CO. [1988] [Dihm
and Carr 1988]
Dixon, K. and Lee, R. Radon Survey of the American Water Works
System. In Radon in Ground Water. Barbara Graves, ed. Lewis
Publishers, Inc. Chelsea, MI. [1987] [Dixon and Lee 1987]
Dyksen, J.E., Raczko, R.F., and Cline, G.C. Operating Experiences at
VOC Treatment Facilities. In Proc. of the 1995 AWWA Annual
Conference. Anaheim, CA. [June 1995] [Dyksen et al. 1995]
Ershow, A.G. and Cantor K.P. Total Water and Tapwater Intake in the
United States: Population-based Estimates of Quantities and Sources.
Report prepared under National Cancer Institute Order #263-MD-
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[[Page 59362]]

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[September 1993] [Wade Miller 1993]

Appendix 1 to the Preamble: What Were the Major Public Comments on
the 1991 NPRM and How Has EPA Addressed Them in This Proposal?

EPA received more than 600 comments on the Notice of Proposed
Rulemaking (NPRM) of July 18, 1991 (56 FR 33050). Of the comments
received, 289 were from public water suppliers, 89 were from
individuals, 76 were from local governments, 52 were from States, 48
were from companies, 43 were from trade/professional organizations,
12 were from Federal agencies, 10 were from health/environmental
organizations, 3 were from Members of Congress, and 2 were from
universities. EPA received additional comments at public hearings on
September 6, 1991, in Washington, DC and on September 12, 1991, in
Chicago, Illinois.
Those commenting raised several concerns, including cost of rule
implementation, especially for small public water systems, and the
larger risk to public health from radon in indoor air from soil
under buildings. The next sections summarize major public comments
on the 1991 NPRM and provide brief responses in the following areas
of most concern: (1) General issues; (2) statutory authority and
requirements; (3) radon occurrence; (4) radon exposure and health
effects; (5) maximum contaminant level; (6) analytical methods; (7)
treatment technologies and costs; and (8) compliance monitoring. In
many instances the following sections refer the reader to applicable
sections in today's preamble where many of the issues have been
fully discussed.

A. General Issues

Additional regulation: Some public comments opposed additional
regulation in general, and additional drinking water regulation in
particular. Some comments also suggested EPA proceed with a more
integrated approach to environmental regulation, i.e., that
mitigation programs be designed to provide control over major
exposure routes, which in the case of radon must take the soil gas
source into account.
EPA Response: At the time of the 1991 proposal, EPA did not have
authority under SDWA for a broader radon rule. However, the SDWA as
amended in 1996 provides such authority. In addition to requiring
EPA to promulgate a regulation for radon in drinking water, the SDWA
radon provision also includes a less stringent alternative maximum
contaminant level (AMCL) and a multimedia approach to address radon
in indoor air. Much of the health threat is associated with radon
emanating from soil gas into indoor air. Risk from drinking water
particularly through the inhalation pathway is also a significant
and preventable risk. Today's proposal addresses all major routes of
exposure and is intended to promote multimedia mitigation (MMM)
programs and implementation of the AMCL. Thus, the Agency expects to
provide more cost-effective reductions in the health risks
associated with radon.
Federal funding for compliance and phased implementation:
Commenters asked the Agency for increased flexibility in complying
with the proposed regulation through phased compliance; cheaper
removal technologies; and/or additional Federal funding. Industry
and other groups also recommended a phased implementation of radon
removal, focusing first on priority water sources with the highest
radon levels.
EPA Response: Today's proposal provides different compliance
dates for compliance with the MCL and with the AMCL/MMM program,
such that there will be sufficient time to implement the MMM
program.
The Agency recognizes that the SDWA regulations will continue to
place a significant burden on some small communities with limited
tax bases and resources with which to attain compliance. The EPA
drinking water State Revolving Fund provides support to the States
and public and private water suppliers, in particular to small
public water suppliers. This fund offers capitalization grants to
the States for low-interest loans to help water systems comply with
the SDWA (For more information refer to Section XIV.C.1 of today's
preamble.)
In addition, EPA surveys of public and private water suppliers
have been initiated to understand more clearly their needs in
particular in terms of funding to support capital improvements in
the context of implementing SDWA-related plans.

B. Statutory Authority and Requirements

Applicability to non-transient, non-community (NTNC) systems:
Ten commenters stated that EPA must provide better justification for
regulating non-transient, non-community water systems along with
community water systems. The indoor occupancy factors and exposure
rates are different for persons in the workplace (i.e., school and
hospital) than in the home. EPA should state clearly how the final
rule will apply to this group.
EPA Response: About one-third of the systems estimated in 1991
as being affected by the final regulation were NTNC water systems.
The Agency requested data in 1991 on NTNC system exposure patterns
but received none; subsequently, the Agency conducted analysis on
limited data on NTNC occurrence and exposure patterns and found the
attendant exposures and risks to be relatively small in comparison
to those estimated for community water supplies. (For more
information refer to Section XI.D of today's preamble.)
In keeping with the flexibility accorded the Agency by SDWA to
focus on areas of cognizable public health risk, EPA proposes that
NTNC water systems not be required to comply with the proposed radon
regulation. At the same time, EPA is soliciting comment and data
related to this issue and has left open its options in terms of the
final radon regulation.
State authority: Commenters felt that the Federal drinking water
regulations should

[[Page 59363]]

not be uniform across the nation's drinking water supply. Many
drinking water issues, including those which involve unique
circumstances in the State and the necessary resources to implement
programs, remain unresolved and perhaps are not resolvable by the
Federal government. As a result, States will need to carry more of
the responsibility in regulating drinking water given their
familiarity with local circumstances.
EPA Response: The Agency acknowledges the unique circumstances
faced by State primacy programs and public water systems. According
to the framework set forth in the SDWA Amendments, States will have
the option of adopting the MCL or the higher AMCL and the MMM
program to address radon in indoor air. State programs in this area
are expected to vary, in part due to radon occurrence patterns
locally and in part due to State resources as they apply to
monitoring public water systems; also States will have flexibility
in MMM program implementation, and through consideration of
variances and exemptions as allowed under SWDA.

C. Radon Occurrence

Radon in PWS (Nationwide): The American Water Works Association
(AWWA) suggested that EPA's 1991 national occurrence estimates for
radon were low compared to actual levels, i.e., greater than 20
percent low, resulting in an inaccurate EPA cost impact estimate.
The Association suggested EPA consider the following changes to the
radon occurrence analysis:
Disaggregation of the National Inorganics and
Radionuclides Survey (NIRS) occurrence data for the smallest public
systems, i.e., those serving fewer than 500 persons, into two
subsets of systems;
An accounting in the radon occurrence analysis for
geologic conditions in various regions by applying NIRS data in an
area-specific manner;
Updating and increasing the inventory (including NTNCs)
based upon FRDS data;
Inclusion of State radon data in the national
occurrence analysis;
EPA analyses may have underestimated radon in water
levels because the location of sampling in NIRS was in the
distribution systems (where natural decay of radon-222 may have been
significant, thereby lowering occurrence estimates).
EPA Response: EPA analyses of these issues addressed the
concerns described previously to the extent feasible (USEPA 1999c).
The EPA analyses have incorporated the referenced issues as data
allowed; the analyses also addressed newer data collected and/or
submitted to EPA.
The Agency used State radon in drinking water data to refine the
previous analysis that were based solely on the NIRS data. The
Agency identified and obtained data from a number of States that
supplement the geographic coverage, representativeness, and utility
of the NIRS data in predicting the occurrence of radon in drinking
water in the U.S. Additional data sets were obtained that, while not
addressing radon distributions in States or regions, provided
significant data related to the sampling, analytical, temporal and
intra-system variability of radon measurements. The data from the
NIRS and from the supplementary data sources were subjected to
extensive statistical analysis to characterize their distribution
and compare data sets.
These analyses are discussed and referenced in today's preamble
Section XI.C. The results indicate that: radon levels seen in the
NIRS data sets were generally slightly lower than those seen in the
wellhead and point-of-entry data provided by the same States (with
radon levels being more comparable in the very small systems due to
short residence times); previous results were verified that radon
levels in the U.S. are the highest in New England, the Appalachian
uplands and other Western and Midwest regions; the levels of radon
seen in the supplemental State data sets were similar to those seen
in the NIRS data for the same regions; and, due to procedures used
to adjust the NIRS data, the proportions of systems exceeding the
various levels in the current study are greater than those seen in
previous analyses.
However, best estimates of the numbers of systems exceeding
regulatory levels in EPA's 1993 estimate for the 1994 EPA Report to
Congress (USEPA 1994) and the central tendency estimates in the
current analysis are quite similar. This is because the total
estimated number of community and non-community non-transient
systems that are believed to be active in the U.S. has decreased
approximately 17 percent between 1993 and the Agency's current
estimates. Part of this difference is due to system consolidation,
and part may be due to improved methods for differentiating active
from inactive systems, although the relative importance of these two
factors is not known.
Occurrence of radon in California: A California drinking water
industry association provided a number of resources including the
following: a survey of its member agencies; a California Department
of Health Services (DHS) Groundwater Study; and the Metropolitan
Water District's (MWD) Southern California Radon Survey. The
commenter produced estimated radon occurrence figures which far
exceeded EPA's California and national occurrence profiles. The
commenter's estimate predicted 75 percent to 97 percent of
California public water systems out of compliance with a radon
standard of 300 pCi/L. The commenter submitted to EPA additional
methods and source data necessary for a complete EPA evaluation of
this comment.
EPA Response: EPA studied the commenter's methodology for
determining radon occurrence in California, proposed water system
categorization scheme, and the sources of radon data (surveys
mentioned previously), and has concluded the following:
That sampling in the California surveys biased the
results towards higher radon levels since data were apparently
collected at the wellhead;
The methods used in combining data sources (and in
substitutions within data sets) resulted in substantial
overestimation of radon occurrence in California ground water
supplies.
The commenter assumed 23 percent more public water
supplies in California than indicated in then-current EPA FRDS
records;
The use of commenter's GIS-predicted radon levels for
California systems was also problematic (USEPA 1999c).
EPA believes that EPA NIRS survey did not under represent the
levels of radon in California. A comparison by EPA of the NIRS-
California data and other California data reveals a similarity in
results. Furthermore, EPA results are more in accord with California
State predictions submitted to EPA during the same comment period.
Variability of radon levels in water: The American Water Works
Service Company (AWWSC) provided technical information on the issue
of radon variability in well water. AWWSC said that the variability
of radon levels in well water is a phenomenon that could affect the
compliance status of systems. AWWA and the Association of California
Water Agencies also echoed concerns about the seasonal and diurnal
variability in groundwater.
EPA Response: EPA analyzed this issue to determine if radon
variability may or may not have any influence on national occurrence
profiles. EPA reviewed the two available sources of information on
radon variability (Kinner et al. 1990), and data supplied by the
American Water Works Service Co. (AWWSC). The Kinner report was
limited to four sites in New Hampshire that exhibited short-term and
long-term variability of radon. The AWWSC data were drawn from 400
wells, nationwide, in 1986 and 1987. Kinner's data appear to
indicate a radon fluctuation of 20 to 50 percent in well water over
long-term intervals, weekly or biweekly. The short-term variability
(15 to 180 minute intervals during a three month test at one site)
showed a fluctuation of 50 percent as observed in the long-term
test. These studies did not try to correlate any of the variability
observed with well yield and water table level to account for the
inconsistent patterns. The data provided were too limited to
independently analyze factors that may have influenced radon level
fluctuations. However, EPA notes that the short-term and long-term
variabilities of radon observed at a single site were similar. This
suggests that the long-term variability may be a reflection of
random sampling where short-term influences are influencing radon
levels.
The AWWSC analysis of radon in well water included sampling in
the fall of 1986 and January 1987. A decrease of 29 percent on
average was found over the two-month period. A change in analytical
procedure accounted for about 10 percent of that difference. The
remaining 19 percent difference was not explained. AWWSC also
conducted a test of the effect of pumping time on radon levels over
a short period (five days then two days), beginning with an idle
period. AWWSC inferred that an observed initial increase in radon
level (about 25 percent) was due to radon decay in water that had
been sitting near the well casing. According to AWWSC, a subsequent
decrease (much smaller) over two days was due to the drawing of less
enriched water from beyond a potential geologic radon source yet
within the cone of depression.

[[Page 59364]]

EPA believes that local geologic and operating conditions may
produce temporal variations in radon levels in ground water sources.
However, data are too limited to permit drawing of any conclusions.
Also, since the Kinner and AWWSC reports cited water that generally
contained radon in the high levels, 2,500 to 200,000 pCi/L, and
1,200 to 1,700 pCi/L, respectively, EPA cannot draw any conclusions
on the effect(s) of short or long-term variability on radon in water
at 300 pCi/L. Because EPA NIRS data represents single, one-time
values for systems sampled, it produces no basis for a bias
conclusion (i.e., over- or under-estimates). On the contrary, the
random nature of the NIRS survey would cancel any differences
between the NIRS level and the ``true average'' radon level in
public supplies.
Radon Emanation from Pipe Scale Deposits: Data received after
the comment period, and subsequently reviewed by EPA, suggested that
due to an existing radon source (radium-226) in some systems, levels
of radon-222 may in some instances increase as water passes through
water distribution systems.
EPA Response: A paper by Valentine et al. (Valentine 1992)
contained data on the phenomenon of radon levels increasing in water
distribution pipelines. In three of five distribution systems
studied in Iowa, the paper's authors found what they refer to as
radon ``hot spots.'' These systems have more radon in delivered
water than at the entry to distribution. However, more
geographically diverse data generally show that natural radon decay
is a more influential factor as water is distributed. In other
words, without nationally-relevant data to the contrary, it would be
expected that within-distribution system radon decay supercedes
radon production, except in very specific circumstances.
A more recent article by Field et al. (1995) reported that a
case study of an Iowa water system with an average of 2.2 mg/L
dissolved iron and 2.5 pCi/L of radium-226. The finished water
entering the distribution system had a mean radon level of 432
54 pCi/L (one standard deviation). Field et al.
measured radon levels at the taps of 25 homes and measured radon
levels ranging from 81 pCi/L to 2,675 pCi/L, with a mean of 1,108
648 pCi/L. The authors concluded that iron scale
deposits were sorbing radium-226, the parent of radon-222. In the
case study reported, greater than 80% of the surface pipe-scale was
comprised by iron oxides, with traces of scales containing calcium
and silicon. Since iron oxides have been shown to selectively
scavenge radium, it is plausible that a co-occurrence of high iron
and radium levels may result in the production of significant levels
of radon within the distribution system. Other factors that would
determine the level of radon produced include concentration of
radium-226 sorbed to the pipe scale, the quantity, distribution, and
surface area of the scale, the composition of the scale, all of
which are determined by the average finished water quality, and the
length of time the water is in contact with the scale. All case
studies were confined to the state of Iowa.
It remains to be shown that the confluence of conditions that
result in significant radon production within distribution systems
exists commonly at the national level or is confined to specific
locales (e.g., areas with high average levels of iron, radium-226,
and other site-specific factors).
Regarding this issue, information available at the present time
does not support a determination as to the extent to which this
phenomenon may occur in the U.S. The Agency is, however, soliciting
comments in today's proposal on the advisability of requiring
additional monitoring for radon as a source of consumer exposure
from the distribution system, and on other radon occurrence issues.

D. Radon Exposure and Health Effects

Approximately 400 public comments were submitted on the
assessments of exposure to and health effects of radon in the 1991
NPRM. The major issues raised in these comments, including comments
regarding the proposed MCLG, are addressed next.
Linear no-threshold dose response model: Many commenters were
concerned that EPA only used a linear no-threshold dose-response
model in projecting cancer risk associated with low level exposure
to radon in the domestic environment.
EPA Response: The shape of the dose-response curve for radon has
been evaluated in detail by the NAS (1999a, 1999b), who concluded
that essentially all available data are consistent with a linear
non-threshold mechanism. This includes data on the effects of a wide
range of ionizing radiation, as well as direct dose-response
relationships observed for radon in animals studies and in studies
of cohorts of underground miners. The EPA concurs with the NAS
evaluation and conclusion.
Age dependence on risk from radon exposure: A few commenters
stated that EPA should consider the effect of exposure at young
ages. According to these commenters, the additional risks in
children were not well addressed.
EPA Response: Data on the relative sensitivity of children to
radon are sparse. In general, the NAS Radon in Drinking Water
Committee concluded that there is insufficient scientific
information to permit quantitative evaluation of the risks of lung
cancer death from inhalation exposure to radon progeny in
susceptible sub-populations such as infants, children, pregnant
women, and elderly and seriously ill persons. However, the BEIR VI
committee (NAS 1999a) noted that there is one study (tin miners in
China) that provides data on whether risks from radon progeny are
different for children, adolescents, and adults. Based on this
study, the committee concluded that there was no clear indication of
an effect of age at exposure, and the committee made no adjustments
in the model for exposures received at early ages. This indicates
that children are not an especially susceptible sub-group. With
respect to cancer risk from ingestion of radon, NAS (1999b)
performed an analysis to investigate the relative contribution of
radon ingestion as a child to the total risk. This analysis
considered the age dependence of water consumption, of the behavior
of radon and its decay products in the body, of organ size, and of
risk. The results indicated that dose coefficients are somewhat
higher in younger people than adults. NAS (1999b) estimated that
about 30 percent of a lifetime risk was due to exposures occurring
during the first 10 years of life.
Uncertainty of radon risk estimates: Several commenters said EPA
needs to provide a more in-depth discussion of the uncertainty
associated with the risk estimates for radon.
EPA Response: EPA has performed a very detailed two-dimensional
Monte Carlo evaluation of variability and uncertainty in exposure
and risk from water-borne radon (USEPA 1993, 1995). The methods and
inputs used by EPA were reviewed by the SAB and by NAS, and the
results were judged to be appropriate and sound, subject to some
refinements in the uncertainty bounds on some of the inputs. Based
on the most recent recommendations from the NAS regarding the
uncertainty in the risk coefficient for ingestion and inhalation
exposure, EPA (1999d) has recalculated the uncertainty bounds around
each risk estimate. In brief, the credible interval around the best
estimate of individual and population risks from inhalation and
ingestion exposure pathways are about four-fold and fourteen-fold,
respectively.
Extrapolation of high dose in mines to lower dose in homes: Many
commenters stated that the differences in dose between the mines and
homes in the 1991 NAS report Comparative Dosimetry of Radon in Mines
and Homes needs to be incorporated into the Agency's radon progeny
inhalation risk calculation.
EPA Response: EPA and NAS both recognize the importance of
potential differences between dose and risk per unit exposure in
mines and in homes. The ratio of the dose to lung cells per WLM in
the home compared to that in a mine is described by the K factor.
Based on the best data available at the time, NAS (1991) had
previously concluded that the dose to target cells in the lung was
typically about 30 percent lower for a residential exposure compared
to an equal WLM exposure in mines (i.e., K=0.7). The BEIR VI
committee re-examined the issue of the relative dosimetry in homes
and mines. In light of new information regarding exposure conditions
in home and mine environments, the committee concluded that, when
all factors are taken into account, the dose per WLM is nearly the
same in the two environments (i.e., a best estimate for the K-factor
is about 1) (NAS 1999a). The major factor contributing to the change
was a downward revision in breathing rates for miners. Thus, NAS has
concluded that the risk coefficient based on miners is appropriate
for use in residences without adjustment.
Possible confounding factors in mine studies: Some commenters
raised questions about the possible confounding factors in the miner
epidemiological studies EPA used to project lung cancer risks.
Commenters stated that, besides radon, exposure to other
contaminants not found at home can produce synergistic effects. Such
other contaminants could include diesel fumes, excessive dust

[[Page 59365]]

(which may be a problem in poorly constructed mines without adequate
ventilation), and other radionuclides like uranium in the mine air.
EPA Response: The effects on radon risk estimates from
potentially toxic exposures to substances such as silica, uranium
dust, blasting fumes, and engine exhaust to underground miner
cohorts were carefully examined in the NAS reports on radon risks
(NAS 1988, 1999a) and other studies. For example, in the Malmberget
iron miner study, Radford and St. Clair Renard (1984) investigated
and determined that the risk from confounders such as tuberculosis,
dust, silica, diesel exhaust, metals and asbestos is negligible.
Edling and Axelson (1983) found the Grangeberg mine atmosphere clean
of arsenic, asbestos and carcinogenic metals. In the Eldorado miner
cohort (NAS 1988), potential confounders were investigated and
exposures to silica and diesel exhaust were very low. In the
Czechoslovakian uranium miners' study, Sevc et al. (1984, 1988)
found that cigarette smoking was the only risk factor other than
radon that was a significant exogenic carcinogenic agent. Two of the
studies (China and Ontario) have quantitative data on arsenic, and
there was no significant variation in excess relative risk per unit
radon exposure across different levels of arsenic exposure (NAS
1999a). Despite the variety of exposures to potentially toxic agents
other than radon, the dose-response between radon and lung cancer
death was approximately consistent across the mining cohorts. NAS
(1988) also noted that animal studies show no evidence of a
synergistic effect of these agents on lung cancer risk from radon.
Taken together, these findings indicate that the effect of
confounding factors on observed lung cancer rates in miners is
likely to be small.
Radon-smoking interaction: Several commenters stated that EPA's
analysis shows that smoking acts synergistically with radon to
induce lung cancer. The risk from radon is, on average, ten times
higher for smokers than for the rest of the population, and over 20
times higher for heavy smokers. Several commenters asked why they
should spend resources to remove a natural contaminant from water
while more than \2/3\ of the related cancer risk is attributable to
the subpopulation who smoke.
EPA Response: Because of the strong influence of smoking on the
risk from radon, the BEIR VI committee (NAS 1999a) evaluated risk to
ever-smokers and never-smokers separately. The BEIR VI committee had
smoking information on five of the miner cohorts, from which they
concluded that there was a submultiplicative interaction between
radon and smoking in causing lung cancer. Based on current smoking
prevalence rates, it is estimated that about 84 percent of all
radon-induced lung cancers will occur in ever-smokers, with only 16
percent in never-smokers. Thus, it is true that a reduction in radon
exposure will save more cancer cases in the cohort of smokers than
nonsmokers, but the relative amount of risk reduction is actually
greater for nonsmokers than smokers.
Epidemiological studies of lung cancer in the home environment.
Some commenters stated that in estimating risk associated with
exposure to radon, EPA should consider health risk data associated
with the exposure to low levels of radon in the domestic
environment.
EPA Response: The NAS (1999a) has recently performed a careful
analysis of epidemiological data on the risk of cancer in residents
from radon. The NAS committee concluded that because of numerous
design and experimental limitations, these studies do not constitute
an adequate data base from which quantitative risk estimates can be
derived. However, the data from studies in residents are considered
to be generally consistent with the predictions based on the miner
data.
Lack of experimental or epidemiological data link exposure via
ingestion to increased cancer rates: Several commenters stated that
no experimental or epidemiologic data link exposure via ingestion to
increased cancer rates. The basis for ingestion risk data was a
surrogate gas, xenon-133, that behaves similarly to radon.
EPA Response: Although no human or animal data directly
demonstrate cancer risk from ingestion of radon, it is certain that
ingested radon is absorbed from the gastrointestinal tract into the
body, that this absorbed radon is distributed to internal tissues
which are then irradiated with alpha particles as the radon and its
progeny undergo decay. That alpha irradiation increases cancer risk
is well established (UNSCEAR 1988; NAS 1990).
EPA's ingestion risk estimate is based on the conclusions from
the NAS Radon in Drinking Water committee (NAS 1999b). The NAS
committee performed a re-evaluation of the risks from ingestion of
radon in direct tap water using the basic approach described in
Federal Guidance Document 13 (USEPA 1998). This involved developing
a new pharmacokinetic model of the behavior of ingested radon, based
primarily on observations of the behavior of ingested radon in
humans, as well as studies using xenon and other noble gases. NAS
also addressed the uncertainties (within an order of magnitude) of
the risk estimates for oral exposure associated with dose estimate
to the stomach and in the epidemiologic data used to estimate the
risk (NAS 1999b). Because the magnitude of the risk posed by
ingestion is about 10 percent of the risk from inhalation of radon
progeny, these uncertainties are not most critical in evaluating the
overall hazards from water-borne radon.
Air-water transfer factor and episodic exposure: As for
inhalation exposure, most commenters supported EPA's proposed radon
water-to-air transfer ratio of 10,000:1. Two commenters regarded
this transfer factor as too conservative.
EPA Response: EPA has performed a detailed evaluation of radon
gas transfer from water to air (USEPA 1993, 1995). Values are highly
variable between buildings, with an average value of about 1E-04.
The NAS has recently performed an independent review of both
measured and modeled values, and the NAS committee also concluded
that a value of 1E-04 is the best point estimate available (NAS
1999b).
Outdoor versus indoor radon concentrations: Some commenters
asserted that the concentration of radon in outdoor air is higher
than the indoor air concentration resulting from the proposed MCL of
300
pCi/L.
EPA Response: EPA agrees. The NAS committee reviewed all the
ambient radon concentration data that are available, and based on
these data concluded that the best estimate of the average ambient
(outdoor) radon concentration in the United States is 0.4 pCi/L of
air. In contrast, based on a transfer factor of 1 x 10^-4,
the contribution to indoor air from an average radon concentration
in water (about 213 pCi/L) is only about 0.021 pCi/L. However, some
groundwater systems have much higher radon concentrations, and
increments in indoor air from water-borne radon may be much higher
in those cases. As required by the Congress. EPA is implementing the
MMM program to address the issue of relative radon risk from water
and air.
Direct tap water ingestion rate: Concerning ingestion intake,
few commenters expressed an opinion on the direct tap water
ingestion rate of 1 L/day. One commenter suggested that the intake
assumption should be 0.7 L/day, and another, 0.25 L/day.
EPA Response: EPA has based its current assessment of this issue
on reports by the National Academy of Sciences and others. The
reader is referred to a fuller discussion in the preamble to today's
proposed radon in drinking water regulation and to references cited
therein (see Section XII).
Radon loss via volatilization prior to ingestion: Two commenters
felt that the 20 percent radon loss from direct tap water before
ingestion is conservative.
EPA Response: Data are limited on the amount of radon lost from
direct tap water before ingestion. Several studies (von Doblin and
Lindell 1964; Hursh 1965; Suomela and Kahlos 1972; Gesell and
Prichard 1980; Horton 1982) suggest a value of about 20 percent as
the central estimate of radon lost before direct ingestion. Because
of the lack of data, the NAS (1999b) recommended that a value of 0
percent (i.e., no loss) be assumed. It is important to note that
this applies only to ``direct tap water'', and that radon loss is
assumed to be nearly complete from other types of water (coffee,
juice, that in foods, etc.).
Concerning the potential additional loss from the stomach prior
to absorption, EPA believes that radon does not escape from the
esophagus. An available study (Correia et al. 1987) conducted by the
Massachusetts General Hospital specifically measured exhaled air
following ingestion of radioactive xenon in drinking water. Gas did
not immediately escape through the mouth. However, the absorption
through the stomach and small intestine transferred xenon to the
bloodstream and lungs. The pharmacokinetic model used to evaluate
risk from ingested radon utilizes this absorption mechanism.
New studies indicating reduced lung cancer risk: Some commenters
asserted that the lung cancer risk estimates will be reduced based
on new studies.
EPA Response: The risk coefficients for lung cancer derived by
NAS (1999a, 1999b) are based on a detailed analysis of all of the
currently available studies.

[[Page 59366]]

Relative risk of radon from soil versus radon from drinking
water: Many commenters stated that the risks posed by radon in water
are small compared to the risk of radon from soil, and that
regulation of radon in water will have very little effect in
reducing the total risk of cancer from radon exposure.
EPA Response: EPA recognizes that the risk to residents
contributed by radon in household water is a relatively small
fraction of the risk contributed by radon released into indoor air
from soil. Based on the most recent quantitative analysis, NAS
estimates that this fraction is only about 1 percent. Nevertheless,
it is still true that radon in water is one of the most hazardous
substances in public water systems, contributing a total of about
160-170 cancer deaths per year. Thus, regulation of radon in water
is appropriate.
Cancer risk posed by radon in drinking water: Radon in drinking
water is one of the water contaminants with the highest estimated
cancer risk.
EPA Response: EPA agrees, and it is for this reason that EPA
believes that regulation of radon in water is necessary and
appropriate. By definition, because radon is a known human
carcinogen, the MCLG is zero.

E. Maximum Contaminant Level

Opposition to a radon MCL of 300 pCi/L: More than 300 commenters
representing trade associations, Federal and State agencies, and
regional and community water suppliers disagreed with a standard of
300 pCi/L for radon in drinking water. The strongest opposition came
from California, Nebraska, and the northeastern region of the United
States. Other commenters suggested the MCL be set at 1,000 pCi/L or
at 2,000 pCi/L.
EPA Response: As referenced in Section A of this Appendix, the
SDWA as amended in 1996 provides EPA authority to utilize an
alternative approach (AMCL with MMM programs), which is expected to
significantly allay concerns of stakeholders and commenters on the
1991 proposal.
Use of cost-effectiveness in standard setting: Local water
agencies throughout California and elsewhere in the United States
insisted that water rates would double, resulting in economic
problems. State and local water agencies were in almost unanimous
agreement that the proposed standard may not be cost-effective,
posing significant financial and administrative burdens on agencies
and customers.
EPA Response: In the past, EPA generally limited consideration
of economic costs under the SDWA to whether a treatment technology
was affordable for large public water systems. Under the SDWA as
amended in 1996, the Agency has conducted considerable analysis in
the areas of cost and technologies for small systems implementing
the radon MCL and on small system compliance technologies. (For more
information on related EPA analyses refer to today's proposal.)
The MCL as proposed in 1991 and in today's action was set within
the EPA regulatory target range of approximately 10^-4 to
10^-6 individual lifetime fatal cancer risk level, to
ensure the health and safety of the country's drinking water supply.
Although this level will prevent numerous fatal cancer cases per
year, the Agency recognizes that this benefit would affect only
radon in ground water or 5 percent of the total radon exposure. The
Agency expects the proposed AMCL/ multimedia approach will result in
greater radon risk reduction at lower cost. (The multimedia
mitigation program and the projected costs and benefits are
described in greater detail in today's proposal.)
Impact on private wells: Several commenters expressed concern
over the potential impact of the proposed standards on private
wells.
EPA Response: The Agency cannot comment on the impact of an
NPDWR (radon standard) on private wells. EPA currently possesses
some data from State surveys that indicate relatively high levels of
radon in private wells. However, the data are distinct from Public
Water System data collected by EPA and others. The statute regulates
public water systems that provide piped water for human consumption
to at least 15 service connections or that serve an average of at
least 25 people for at least 60 days each year. Public water systems
can be community; non-transient, non-community; or transient non-
community systems. As a supplement to Federal coverage, some States
extend their authority by regulating systems serving 10 people or
fewer.

F. Analytical Methods

Availability of qualified laboratories and personnel: Commenters
stressed the impact the proposed regulation may have on requirements
for analytical laboratory certification and training of laboratory
technicians. For example, one State wrote that it has no
certification process through which laboratories can receive State
certification for radionuclide analyses. Another commenter stressed
the need for a strategy to work with individual States to ensure
sufficient certified analytical laboratory capacity.
EPA Response: The current situation and expected changes in the
processes governing laboratory approval and certification are
discussed in some detail in today's preamble (Section VIII.B). One
of the changes since 1991 is the formation of the National
Environmental Laboratory Accreditation Conference (NELAC) in 1995.
NELAC serves as a voluntary national standards-setting body for
environmental laboratory accreditation, and includes members from
both state and Federal regulatory and non-regulatory programs having
environmental laboratory oversight, certification, or accreditation
functions. The members of NELAC meet bi-annually to develop
consensus standards through its committee structure. These consensus
standards are adopted by participants for use in their own programs
in order to achieve a uniform national program in which
environmental testing laboratories will be able to receive one
annual accreditation that is accepted nationwide. The intent of the
NELAC standards setting process is to ensure that the needs of EPA
and State regulatory programs are satisfied in the context of a
uniform national laboratory accreditation program. EPA shares
NELAC's goal of encouraging uniformity in standards between primacy
States regarding laboratory proficiency testing and accreditation.
Four-day holding period between sampling and analysis: Several
commenters contended that for laboratories to cope with the
increased number of samples, the holding period should increase to
eight days. A State agency suggested a holding period of seven days.
Another commenter stated that the proposed four-day holding period
was not possible because many ground water systems have sources
distributed over large areas that may need sampling. Certified
personnel will collect, record, package, and send the samples to
analytical laboratories within four days. Also, with a 100-minute
counting time requirement, commercial laboratories may be ill-
equipped to analyze samples from 28,000 systems. Another State
commented that the four-day holding period was not compatible with a
standard work week.
Response: Standard Method 7500-Rn reports a 50 minute counting
time (not 100 minutes) and a four day sample holding time. This
combination of counting time and holding time has been determined to
be a good trade-off, given the limitation of the 3.8 day half-life
of radon. Doubling the sample holding time (i.e., eight days) would
approximately triple the counting time (i.e., to 150 minutes)
necessary to achieve the same level of certainty in the analytical
results, which would probably result in much higher analytical
costs. Since the sample counting procedure is capable of being
highly automated, EPA believes that certified laboratories will be
able to process the required samples with a four-day holding time.
As an example, one laboratory contacted by EPA currently analyzes
radon in 12,000 water samples per year as part of a ground water
monitoring study, providing evidence that a demand for radon
analytical capacity will result in the required laboratory capacity.
Based on an evaluation of the potential for laboratory
certification, performance testing, and analytical procedures, which
included input from stakeholders, the four day holding time has been
determined to be feasible, and should result in lower analytical
costs than a longer holding time and a longer counting time.
Proposed analytical techniques: A commenter representing a group
of utilities approved of direct, low-volume liquid scintillation for
measurement of radon as proposed, but recommended the use of Lucas
Cell de-emanation for measurement of Ra-226 (not also for radon, as
proposed). According to this commenter, the liquid scintillation
method for radon measurement is straightforward and efficient
compared with the Lucas Cell method that requires a high degree of
specialized skill. Also, equipment cost for the Lucas Cell method
may be prohibitive. The Conference of Radiation Control Program
Directors stated that liquid scintillation, while able to detect
radon in water at low levels, may provide laboratory results that
are not reliable.
EPA Response: EPA agrees that LSC has the stated advantages
relative to de-

[[Page 59367]]

emanation. EPA also expects that the vast majority of nationwide
radon analysis will be done using LSC. However, some laboratories
are already equipped to perform the de-emanation method. Since the
de-emanation method performs acceptably well, there is no reason to
refuse the possibility of the added laboratory capacity afforded by
the approval of this method.
Precision variability: A local water agency and an engineering
company representative stated that the 30% precision variability is
inadequate for determining compliance because of the extensive
natural variability in radon levels over time. The combination of
counting error, sampling error, and holding time variability demands
a precision of 20%, which would lead to more consistent
data.
EPA Response: EPA agrees that the 1991 proposal of an acceptance
level of 30%, based on a radon ``practical quantitation
level'' (PQL) of 300 pCi/L is not supportable. This conclusion is
based on an extensive collaborative study of the liquid
scintillation method and the de-emanation method for radon published
by EPA in 1993, as described in the methods section (VIII.b) of the
preamble to this proposal. Today's proposal contains several options
for ensuring that compliance monitoring is performed using radon
methods with acceptable accuracy and precision. Based on other
comments to the 1991 radionuclides proposal, EPA's preferred option
is that the method detection limit (MDL) be used as the measure of
sensitivity for radon, and not a PQL, consistent with the use of the
MDL as the basis for sensitivity in the current radionuclides rule.
EPA is proposing a value of 12 12 pCi/L as the MDL for
radon.
Based on the collaborative study data, EPA's best recommendation
for acceptance limits for performance evaluations is 5%
for single measurements, and for triplicate measurements,
6% at the 95% confidence level, and 9% at
the 99% confidence level.

G. Treatment Technologies and Cost

Water Treatment Costs: Industry groups and several utilities
provided detailed analyses of unit treatment costs for removal of
radon in water. Water treatment cost estimates prepared by a
consultant were up to five times the costs estimated by EPA. An
analysis produced by a consultant showed that among the different
factors influencing annual compliance costs estimated by them, unit
treatment costs have the largest impact.
EPA Response: EPA disagrees that its radon aeration treatment
estimates supporting the 1991 radionuclides proposal were under-
estimates. EPA analyzed the aeration cost model and the cost
elements put forward by the industry commenters and summarized the
major differences between the EPA and industry models. This summary
may be obtained from the docket supporting today's proposal (USEPA
1992). While this summary accounts for the differences in cost
estimates between EPA and the industry and utility estimates, it is
not necessary to go into detail regarding these differences since
overwhelming evidence suggests that EPA's 1992 cost estimates were
much closer to actual unit costs, based on costs reported in case
studies collected since 1991 (USEPA 1999a, AWWARF 1998a) than the
commenter's estimates. A comparison of EPA's current unit capital
cost estimates to actual capital costs reported in published case
studies can be found in Figure VIII.A.1 of this preamble. The
consultant's 1991 estimates are compared against case studies and
against EPA's current estimates in an EPA memorandum dated July 28,
1999 (USEPA 1999b). In summary, the consultant's estimates over-
estimated the small systems case studies by factors ranging from
three for small systems with design flows of around 1 MGD down to
around 0.3 MGD. For the smallest systems case studies (systems
serving around 0.015 MGD), the consultant's estimates were high by a
factor of more than twenty. For large systems, the consultant's
estimates were two to three times higher than the best fit for the
large system case studies. As can be seen in Figure VIII.A.1
(``Total Capital Costs: Aeration Cost Case Studies''), EPA's current
unit capital cost estimates appear to be very conservative compared
to small systems case studies (systems with design flows less than 1
MGD) and are typical of case studies for larger flows (design flows
greater than 1 MGD). It should be noted the costs reported for these
case studies are total capital costs and include all process costs,
as well as pre- and post-treatment capital costs, land, buildings,
and permits. Figures VIII.A.1 through VIII.A.3 shown in the preamble
provide strong evidence that EPA's assumptions affecting its unit
cost estimates are realistic for large systems and are conservative
for small systems.
Additional Treatment--Disinfection: Commenters asserted that
some systems may need to add disinfection treatment to protect
aerated water supplies from biological contamination. It was also
stated that about 58 percent of small systems and 12 percent of
large systems may need to add disinfection technology.
EPA Response: The current cost analysis assumes that all systems
adding aeration and GAC will disinfect. For those systems not
already disinfecting (proportions estimated from the EPA 1997
Community Water System Survey), it was assumed that systems adding
treatment would also add disinfection.
Pretreatment for Iron and Manganese: A commenter also challenged
EPA's position on the minimal pretreatment of a ground water supply
before air stripping of radon. The commenter presumed that iron and
manganese fouling will require additional treatment. While the
comment did not address the costs to pre-treat water for iron and
manganese removal, it was mentioned this pretreatment would result
in high potential costs to water systems.
EPA Response: EPA has re-evaluated its assumptions regarding
iron and manganese (Fe/Mn) fouling and has included costs for
chemical stabilization (sequestration) of Fe/Mn for 25% of small
systems and 15% of large systems. Based on an analysis of the
occurrence of Fe/Mn in raw and finished ground water, EPA believes
that this is adequate to account for Fe/Mn control. Data sources for
this evaluation were: ``National Inorganics and Radionuclides
Survey'' (NIRS); American Water Works Association, ``Water:/Stats,
1996 Survey: Water Quality''. and U.S. Geological Survey, ``National
Water Information System''). This analysis is more fully discussed
in Section VIII of the preamble. EPA reiterates that if its Fe/Mn
cost assumptions were invalid, this fact would be demonstrated in
comparisons of its estimates of capital and O&M costs against those
reported in the case studies cited in the preamble. As described
previously, EPA's unit cost estimates are apparently conservative
for small systems and seem to be typical of large systems.
Aeration as BAT and Use of Carbon Treatment: A major commenter
and a city in California asserted that aeration treatment for radon
could potentially create a problem in air emissions permitting.
Also, a major commenter commented that systems with high radon
levels in water could produce high levels of radon in off-gas,
potentially creating a shift among utilities to activated carbon
treatment and waste (radioactive) disposal problems.
EPA Response: EPA discusses this concern in some detail in
Section VIII of the preamble, including an evaluation of the
estimates of the potential risks. Results from a survey of nine
California air permitting agencies regarding permitting requirements
and costs for radon treatment is also described in the preamble. The
full text of this survey is reported in EPA 1999a.
Centralized Treatment Assumption: Commenters from the regulated
community challenged EPA's cost analysis assumption involving
centralized water treatment for radon. These associations cited the
then-current EPA Community Water Supply Survey of 1986 and the then-
current Water Industry Database. They suggested centralized
treatment facilities were unrealistic and under predicts the costs
to public water systems. The industry asserted that the number of
wells and well groupings per system (with numbers increasing with
increasing system size) will likely determine the number of
treatment sites. An industry group produced estimated distributions
of the percent of systems that would require treatment sites.
EPA Response: Centralized treatment was not assumed in the
current radon cost analysis. EPA's current estimate of national
compliance costs for the proposed radon rule uses the distribution
of wells (treatment sites) per ground water system as a function of
water system size from the 1997 Community Water System Survey (USEPA
1997). EPA assumed that a given system's total flow would be evenly
distributed between the total number of wells at the system. To
estimate the radon occurrence at a particular well within a system
with multiple wells, EPA used its evaluation of intra-system
occurrence variability (the variability of radon occurrence between
wells within a given system) to estimate individual well radon
levels. If multiple wells were predicted to be impacted at a given
system, the cost model assumes that treatment is installed at each
well requiring treatment.
Integrated approach to waste management: Three commenters
declared that compliance with the radionuclides rule will create
radioactive waste that may or may not be

[[Page 59368]]

disposable. They recommended an integrated environmental management
approach in addressing this waste issue.
EPA Response: The Agency used an integrated environmental
management approach to determine BAT in removing contaminants from
drinking water. While Packed Tower Aeration (PTA), the BAT for
radon, does not generate waste requiring disposal, granular
activated carbon is of concern. While not BAT, granular activated
carbon may be used by very small systems to remove radon. Waste
disposal issues regarding GAC treatment for radon are discussed in
some detail in Section VIII of this preamble. For more information,
see NAS 1999b and AWWARF 1998a and AWWARF 1998b.

H. Compliance Monitoring

Sampling location: Four State environmental/health agencies, one
private non-environmental firm, eight public water suppliers, and
one water association suggested that radon sampling of the
distribution system at the point of entry does not allow systems to
account for decay and aeration of radon during distribution.
According to these commenters, sampling is more effective closer to
the point of use.
EPA Response: EPA's proposal requires sampling at the entry
points to the distribution system to assure compliance with the MCL
for the water delivered to every customer. All samples will be
required to be finished water, as it enters the distribution system
after any treatment and storage. This approach allows systems to
account for the decay and aeration of radon during treatment and
storage before it enters the distribution system and at the same
time offers maximum protection to the consumer. It is expected that
radon levels would progressively decrease within the distribution
system, downstream from the point of entry. Therefore, consumers who
are located closest to the point of entry are exposed to higher
levels of radon that those further downstream. In order to assure
maximum protection to all of the consumers, EPA requires sampling at
the entry points to the distribution system.
Compliance period: Clarification concerning the frequency of
compliance periods, specifically in regards to the specific timing
for the commencement of water systems monitoring is warranted.
EPA Response: The proposed monitoring requirements for radon are
consistent with the monitoring requirements for regulated drinking
water contaminants, as described in the Standardized Monitoring
Framework (SMF) promulgated by EPA under the Phase II Rule of the
National Primary Drinking Water Regulations (NPDWR) and revised
under Phases IIB and V. The goal of the SMF is to streamline the
drinking water monitoring requirements by standardizing them within
contaminant groups and by synchronizing monitoring schedules across
contaminant groups.
Systems already on-line must begin initial monitoring for
compliance with the MCL/AMCL by the compliance dates specified in
the rule (i.e., 3 years after the date of promulgation or 4.5 years
after the date of promulgation). New sources connected on-line must
satisfy initial monitoring requirements.
Initial compliance with the MCL/AMCL will be determined based on
an average of 4 quarterly samples taken at individual sampling
points in the initial year of monitoring. Systems with averages
exceeding the MCL/AMCL at any well or sampling point will be deemed
to be out of compliance. Systems exceeding the MCL/AMCL will be
required to monitor quarterly until the average of 4 consecutive
samples are less than the MCL/AMCL. Systems will then be allowed to
collect one sample annually if the average from four consecutive
quarterly samples is less than the MCL/AMCL and if the State
determines that the system is reliably and consistently below MCL/
AMCL.
Systems that primarily use surface water, supplemented with
ground water: One water association suggested that public water
systems supplementing their surface water supply with ground water
are not in violation. Since the actual lifetime risk involved is
significantly lower than those systems using 100 percent ground
water supply, an equitable method of compliance for this type of
combined systems should be administered.
EPA Response: In today's proposal, systems relying exclusively
on surface water as their water source are not required to sample
for radon. Systems that rely in part on ground water during low-flow
periods about one quarter of the year are considered public ground
water systems. According to the ground water monitoring
requirements, systems are subject to monitor finished water at each
entry point to the distribution system for radon during periods of
ground water use. For the purpose of determining compliance, systems
supplementing their surface water during part of the year will use a
value of \1/2\ the detection limit for radon for averaging purposes
for the quarters when the water system is not supplemented by ground
water. The water system having ground water samples supplementing
surface water with a radon detection level above the MCL would not
be out of compliance provided that these samples do not cause the
average to exceed the MCL when averaged with the value of \1/2\ the
detection limit during the quarters the ground water source is not
in use.
Averaging quarterly samples: Commenters recommended clarifying
the discussion concerning the averaging of initial measurements to
determine compliance. They stated that averaging the first year
quarterly samples with the annual second and third compliance years
will defeat the purpose of quarterly samples detecting signs of
seasonal variability.
EPA Response: EPA is retaining the quarterly monitoring
requirement for radon as proposed initially in the 1991 proposal to
account for variations such as sampling, analytical and temporal
variability in radon levels. Results of analysis of data obtained
since 1991, estimating contributions of individual sources of
variability to overall variance in the radon data sets evaluated,
indicated that sampling and analytical variance contributes less
than 1 percent to the overall variance. Temporal variability within
single wells accounts for between 13 and 18 percent of the variance
in the data sets evaluated, and a similar proportion (12-17 percent)
accounts for variation in radon levels among wells within systems
(USEPA 1999c).
For today's proposal, the Agency performed additional analyses
to determine whether the requirement of initial quarterly monitoring
for radon was adequate to account for seasonal variations in radon
levels and to identify non-compliance with the MCL/AMCL. Results of
analysis based on radon levels modeled for radon distribution for
ground water sources and systems (USEPA 1999c) in the U.S. show that
the average of the first four quarterly samples provides a good
indication of the probability that the long-term average radon level
in a given source would exceed an MCL or AMCL. Tables A.1 and A.2
show the probability of the long-term average radon level exceeding
the MCL and AMCL at various averages obtained from the first four
quarterly samples from a source.

Table A.1.--The Relationship Between the First-Year Average Radon Level
and the Probability of the Long-Term Radon Average Radon Levels
Exceeding the MCL
------------------------------------------------------------------------
Then the probability that the
If the average of the first four long-term average radon level
quarterly samples from a source is: in that source exceeds 300
pCi/L is:
------------------------------------------------------------------------
Less than 50 pCi/L....................... 0 percent
Between 50 and 100 pCi/L................. 0.5 percent
Between 100 and 150 pCi/L................ 0.4 percent
Between 150 and 200 pCi/L................ 7.2 percent
Between 200 and 300 pCi/L................ 26.8 percent
------------------------------------------------------------------------

Table A.2.--The Relationship Between the First-Year Average Radon Level
and the Probability of the Long-Term Radon Average Radon Levels
Exceeding the AMCL
------------------------------------------------------------------------
Then the probability that the
If the average of the first four long-term average radon level
quarterly samples from a source is: in that source exceeds 4000
pCi/L is:
------------------------------------------------------------------------
Less than 2,000 pCi/L.................... Less than 0.1 percent
Between 2,000 and 2,500 pCi/L..... 9.9 percent
Between 2,500 and 3,000 pCi/L..... 15.1 percent
Between 3,000 and 4,000 pCi/L..... 32.9 percent
------------------------------------------------------------------------

[[Page 59369]]

Water systems with a history of compliance: EPA has provided for
the grandfathering of prior monitoring data for granting waivers.
Monitoring data collected after January 1, 1985, that are generally
consistent with the requirements of the section, and includes at
least one sample taken on or after January 1, 1993, may be accepted
by the State to satisfy the initial monitoring requirements. Many
systems meeting the current monitoring requirements should qualify
for this grandfathering provision because each sampling point or
source water intake will be monitored within the preceding four-year
period. New sampling points, or sampling points with new sources,
must take an initial sample within the year the new source or
sampling point begins operation.
EPA Response: Today's proposal provides that at a State's
discretion, sampling data collected after the proposal could be used
to satisfy the initial sampling requirements for radon, provided
that the system has conducted a monitoring program not less
stringent than that specified in the regulation and used analytical
methods specified in the proposed regulation. The Agency wants to
provide water suppliers with the opportunity to synchronize their
monitoring program with other contaminants and to get an early start
on their monitoring program if they wish to do so.
The proposed regulation provides for the States to grant
monitoring waiver reducing monitoring frequency to once every nine
years (once per compliance cycle) provided the system demonstrates
that it is unlikely that radon levels in drinking water will occur
above the MCL/AMCL. In granting the waiver, the State must take into
consideration factors such as the geological area where the water
source is located, and previous analytical results which demonstrate
that radon levels do not occur above the MCL/AMCL. The waiver will
be granted for up to a nine year period. (Given that all previous
samples are less than \1/2\ the MCL/AMCL, then it is highly unlikely
that the long-term average radon levels would exceed the MCL/AMCL.)

References Cited in Appendix 1 to the Preamble

American Water Works Association Research Foundation. Critical
Assessment of Radon Removal Systems for Drinking Water Supplies,
Denver, CO. [December 1998] [AWWARF 1998a]
American Water Works Association Research Foundation. Assessment of
GAC Adsorption for Radon Removal. Final Draft, Denver, CO. [April
1998] [AWWARF 1998b]
Correia, J.A., Weise, S.B., Callahan, R.J., and Strauss, H.W. The
Kinetics of Ingested Rn-222 in Humans Determined from Measurements
with Xe-133. Massachusetts General Hospital, Boston, MA, unpublished
report (As cited in Crawford-Brown 1990). [1987] [Correia, et al.
1987]
Crawford-Brown, D.J. Final Report: Risk and Uncertainty Analysis for
Radon in Drinking Water. American Water Works Association, Denver,
CO. [1992] [Crawford-Brown 1992]
Edling, C. and Axelson, O. Quantitative Aspects of Radon Daughter
Exposure and Lung Cancer in Underground Miners, Br. J. Ind. Med.
(40:182-187) [1983] [Edling and Axelson 1983]
Ershow, A.G. and Cantor, K.P. Total Water and Tapwater Intake in the
United States: Population-based Estimates of Quantities and Sources.
Report prepared under National Cancer Institute Order #263-MD-
810264. [1989] [Ershow and Cantor 1989]
Federal Register, Vol. 64, No. 38. Health Risk Reduction and Cost
Analysis (HRRCA) for Radon in Drinking Water: Notice, Request for
Comments and Announcement of Stakeholder Meeting. (Feb. 26, 1999)
9559-9599. [64 FR 9559]
Field, R.W., Fisher, E.L., Valentine, R.L., and Kross, B.C. Radium-
Bearing Pipe Scale Deposits: Implications for National Waterborne
Radon Sampling Methods. Am.J. Public Health (85:567-570) [April
1995] [Field et al. 1995]
Gesell, T.F. and Prichard, H.M. The Contribution of Radon in Tap
Water to Indoor Radon Concentrations. In: Gesell T.F. and W.M.
Lowder, eds. Natural radiation environment III, Vol. 2. Washington,
DC: U.S. Department of Energy, Technical Information Center, pp.
1347-1363. CONF-780422 (Vol. 2). [1980] [Gesell and Prichard 1980]
Horton, T.R. Results of Drinking Water Experiment. Memorandum from
T.R. Horton of the Environmental Studies Branch to Charles R.
Phillips. [1982] [Horton 1982]
Hursh, J.B., Morken, D.A. Davis, T.P., and Lovaas, A. The Fate of
Radon Ingested by Man. Health Phys. (11:465-476). [1965] [Hursh, et
al. 1965]
Kinner, N.E., Malley, J.P., and Clement, J.A. Radon Removal Using
Point-of-Entry Water Treatment Techniques. EPA/600/2-90/047.
Cincinnati, OH: Risk Reduction Engineering Laboratory. [1990]
[Kinner, et al. 1990]
National Academy of Sciences, National Research Council. Health Risk
of Radon and Other Internally Deposited Alpha-Emitters: (BEIR IV)
National Academy Press, Washington, DC. [1988] [NAS 1988]
National Academy of Sciences, National Research Council. Health
Effects of Exposure to Low Levels of Ionizing Radiation (BEIR V).
National Academy Press, Washington, DC. [NAS 1990]
National Academy of Sciences, National Research Council. Comparative
Dosimetry of Radon in Mines and Homes. National Academy Press,
Washington, DC. [NAS 1991]
National Academy of Sciences, National Research Council. Health
Effects of Exposure to Radon. (BEIR VI.) National Academy Press,
Washington, DC. [NAS 1999a]
National Academy of Sciences, National Research Council, Committee
on the Risk Assessment of Exposure to Radon in Drinking Water, Board
on Radiation Effects Research. Risk Assessment of Radon in Drinking
Water. National Academy Press, Washington, DC. [NAS 1999b]
National Institute of Occupational Safety and Health. Criteria for a
Recommended Standard: Occupation Exposure to Radon Progeny in
Underground Mines. U.S. Government Printing Office. [1987] [NIOSH
1987]
Pennington, J.A. Revision of the Total Diet Study Food List and
Diets. J. Am. Diet. Assoc. (82:166-173) [1983] [Pennington 1983]
Radford, E.P. and St. Clair Renard, K.G. Lung Cancer in Swedish Iron
Miners Exposed to Low Doses of Radon Daughters. N. Engl. J. Med.
(310(23):1485-1494) [1984] [Radford and St. Clair Renard 1984]
Sevc J., Kunz, E., Placek, V., and Smid, A. Comments on Lung Cancer
Risk Estimates. Health Phys. (46: 961-964) [1984] [Sevc, et al.
1984]
Sevc, J., Kunz, E., Tomasek, L., Placek, V., and Horacek, J. Cancer
in Man after Exposure to Rn Daughters. Health Phys. (54:27-46)
[1988] [Svec, et al. 1988]
Suomela M. and Kahlos, H. Studies on the Elimination Rate and the
Radiation Exposure Following Ingestion of 222-Rn Rich Water. Health
Phys. (23:641-652) [1972] [Suomela and Kahlos 1972]
United Nations Scientific Committee on the Effects of Atomic
Radiation. Sources, Effects and Risks of Ionizing Radiation. United
Nations, NY. [1988] [UNSCEAR 1988]
U.S. Environmental Protection Agency, Office of Radiation Programs.
An Estimation of the Daily Average Food Intake by Age and Sex for
Use in Assessing the Radionuclide Intake of Individuals in the
General Population. EPA 520/1-84-021. [1984] [USEPA 1984]
U.S. Environmental Protection Agency. Examination of Kennedy/Jenks
Cost Estimates for Radon Removal by Packed Column Air Stripping.
Memorandum to Marc Parrotta, ODW, from Michael Cummins, ODW.
[November 23, 1992] [USEPA 1992]
U.S. Environmental Protection Agency, Office of Science and
Technology, Office of Radiation and Indoor Air, Office of Policy,
Planning, and Evaluation. Uncertainty Analysis of Risks Associated
with Exposure to Radon in Drinking Water. TR-1656-3B. [April 30,
1993] [USEPA 1993]
U.S. Environmental Protection Agency, Office of Water. Report to
United States Congress on Radon in Drinking Water: Multimedia Risk
Assessment of Radon. EPA-811-R-94-001. [March 1994] [USEPA 1994]
U.S. Environmental Protection Agency, Office of Science and
Technology, Office of Radiation and Indoor Air, Office of Policy,
Planning and Evaluation. Uncertainty Analysis of Risks Associated
with Exposure to Radon in Drinking Water. EPA 822-R-96-005. [March,
1995] [USEPA 1995]
U.S. Environmental Protection Agency, Office of Ground Water and
Drinking Water. Community Water System Survey. Volume II: Detailed
Survey Result Tables and Methodology Report. EPA 815-R-97-0016.
[January 1997] [USEPA 1997]
U.S. Environmental Protection Agency, Office of Radiation and Indoor
Air. Health Risks from Low-Level Environmental Exposure to
Radionuclides. Federal

[[Page 59370]]

Guidance Report No. 13. Part I--Interim Version. EPA 401/R-97-014.
[1998] [USEPA 1998]
U.S. Environmental Protection Agency. Technologies and Costs for the
Removal of Radon from Drinking Water. Prepared by Science
Applications International Corporation for EPA. [May 1999] [USEPA
1999a]
U.S. Environmental Protection Agency. EPA's Unit Capital Cost
Estimates for Aeration for Radon Treatment Versus AWWA and ACWA's
Estimates from 1992 (Kennedy/Jenks Report) and AWWARF 1995.
Memorandum to Sylvia Malm, OGWDW, from William Labiosa, OGWDW. [July
28, 1999] [USEPA 1999b]
U.S. Environmental Protection Agency, Office of Ground Water and
Drinking Water. Methods, Occurrence and Monitoring Document for
Radon. Draft. [August 3, 1999] [USEPA 1999c]
U.S. Environmental Protection Agency, Office of Science and
Technology. Draft Criteria Document for Radon in Drinking Water.
[June 1999] [USEPA 1999d]
Valentine, R., Stearns, S., Kurt, A., Walsh, D., and Mielke, W.
Radon and Radium from Distribution System and Filter Media Deposits.
Presented at AWWA Water Quality Technology Conference, Toronto.
[November, 1992] [Valentine et al. 1992]
von Dobeln, W. and Lindell, B. Some Aspects of Radon Contamination
Following Ingestion. Arkiv for Fysik. 27:531-572 [1964] [von Dobeln
and Lindell 1964]

List of Subjects

40 CFR Part 141

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

40 CFR Part 142

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

Dated: October 19, 1999.
Carol M. Browner,
Administrator.

For the reasons set out in the preamble, the Environmental
Protection Agency proposes to amend 40 CFR parts 141 and 142 as
follows:

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.

2. Section 141.2 is amended by adding definitions of ``Alternative
Maximum Contaminant Level (AMCL)'' and ``Multimedia Mitigation (MMM)
Program Plan'' in alphabetical order, to read as follows:

Sec. 141.2 Definitions.

* * * * *
Alternative Maximum Contaminant Level (AMCL) is the permissible
level of radon in drinking water delivered by a community water system
in a State with an EPA-approved multimedia mitigation (MMM) program
plan, or by a community water system with a State-approved local MMM
program plan.
* * * * *
Multimedia Mitigation (MMM) Program Plan is a State or community
water system program plan of goals and strategies developed with public
participation to promote indoor radon risk reduction. MMM programs for
radon in indoor air may use a variety of strategies, including public
education, testing, training, technical assistance, remediation grant
and loan or incentive programs, or other regulatory or non-regulatory
measures.
* * * * *
3. Section 141.6 is amended by adding paragraph (j) to read as
follows:

141.6 Effective dates.

* * * * *
(j) The regulations set forth in Subpart R of this part are
effective [60 days after date of publication of the final rule in the
Federal Register].

Subpart C--[Amended]

4. A new Sec. 141.20 is added to Subpart C to read as follows:

Sec. 141.20 Analytical methods, monitoring, and compliance
requirements for radon.

(a) Analytical methods. (1) Analysis for radon shall be conducted
using one of the methods in the following table:

Proposed Analytical Methods for Radon in Drinking Water
----------------------------------------------------------------------------------------------------------------
References (method or page number)
Methodology ---------------------------------------------------------------------------
SM ASTM EPA
----------------------------------------------------------------------------------------------------------------
Liquid Scintillation Counting....... 7500-Rn\1\.............. D 5072 92\2\........... .......................
De-emanation........................ ........................ ....................... EPA 1987\3\
----------------------------------------------------------------------------------------------------------------
\1\ Standard Methods for the Examination of Water and Wastewater. 19th Edition Supplement. Clesceri, L., A.
Eaton, A. Greenberg, and M. Franson, eds. American Public Health Association, American Water Works
Association, and Water Environment Federation. Washington, DC. 1996.
\2\ American Society for Testing and Materials (ASTM). Standard Test Method for Radon in Drinking Water.
Designation: D 5072-92. Annual Book of ASTM Standards. Vol. 11.02. 1996.
\3\ Appendix D, Analytical Test Procedure, ``The Determination of Radon in Drinking Water''. In ``Two Test
Procedures for Radon in Drinking Water, Interlaboratory Collaborative Study''. EPA/600/2-87/082. March 1987.
p. 22.

(2) Sample collection for radon shall be conducted using the sample
preservation, container, and maximum holding time procedures specified
in the following table.

Sampling Methods and Sample Handling, Preservation, and Holding Time
----------------------------------------------------------------------------------------------------------------
Maximum holding time
Sampling methods Preservative Sample Container for sample
----------------------------------------------------------------------------------------------------------------
(i) As described in SM 7500-Rn\1\... Ship sample in an Glass with teflon-lined 4 days.
insulated package to septum.
avoid large temperature
changes.

[[Page 59371]]

(ii) As described in EPA 1987\2\ ...
----------------------------------------------------------------------------------------------------------------
\1\ Standard Methods for the Examination of Water and Wastewater. 19th Edition Supplement. Clesceri, L., A.
Eaton, A. Greenberg, and M. Franson, eds. American Public Health Association, American Water Works
Association, and Water Environment Federation. Washington, DC. 1996.
\2\ ``Two Test Procedures for Radon in Drinking Water, Interlaboratory Collaborative Study''. EPA/600/2-87/082.
March 1987.

(b) Monitoring and compliance requirements. Community water systems
(CWSs) shall conduct monitoring to determine compliance with the
maximum contaminant level (MCL) or alternate maximum contaminant level
(AMCL) specified in Sec. 141.66 in accordance with this chapter. The
monitoring requirements have been developed to be consistent with the
Phase II/V monitoring schedule.
(1) Applicability and sampling location. CWSs using a ground water
source or CWSs using ground water and surface water sources (for the
purpose of this section hereafter referred to as systems) shall sample
at every entry point to the distribution system which is representative
of each well after treatment and/or storage (hereafter called a
sampling point) under normal operating conditions in accordance with
paragraph (b)(2) of this section.
(2) Monitoring--(i) Initial monitoring requirements. (A) Systems
must collect four consecutive quarterly samples beginning by the date
specified in Sec. 141.301(b).
(B) States may allow previous sampling data collected after [60
days after date of publication of the final rule] to satisfy the
initial monitoring requirements, provided the system has conducted
monitoring to satisfy the requirements specified in this section. If a
system's early monitoring data indicates an MCL/AMCL exceedence, the
system will not be considered in violation until the end of the
applicable initial monitoring period specified in Sec. 141.301(b).
(ii) Routine monitoring requirements. Systems must continue
quarterly monitoring until the running average of four consecutive
quarterly samples is less than the MCL/AMCL. If the running average of
four consecutive quarterly samples is less than the MCL/AMCL then
systems may conduct annual monitoring at the State's discretion.
(iii) Reduced monitoring requirements. States may allow systems to
reduce the frequency of monitoring to once every three years (one
sample per compliance period) beginning the following compliance period
provided the systems:
(A) Demonstrate that the average of four consecutive quarterly
samples is below \1/2\ MCL/AMCL;
(B) No individual samples exceed the MCL/AMCL; and
(C) The States determine that the systems are reliably and
consistently below the MCL/AMCL.
(iv) Increased monitoring requirements. (A) Systems which exceed
the MCL/AMCL shall monitor quarterly beginning the quarter following
the exceedence. States may allow systems to reduce their monitoring
frequency if the requirements specified in paragraph (b)(2)(iii) or
(b)(2)(iv)(B) of this section are met.
(B) Systems monitoring once every three years, or less frequently,
which exceed \1/2\ MCL/AMCL shall begin annual monitoring the year
following the exceedence. Systems may reduce monitoring to once every
three years if the average of the initial and three consecutive annual
samples is less than \1/2\ MCL/AMCL and the State determines the system
is reliably and consistently below the MCL/AMCL.
(C) If a community water system has a portion of its distribution
system separable from other parts of the distribution system with no
interconnections, increased monitoring need only be conducted at points
of entry to those portions of system.
(v) Failure to conduct monitoring as described in this section is a
monitoring violation.
(3) Monitoring waivers. (i) States may grant a monitoring waiver to
systems provided that:
(A) The system has completed initial monitoring requirements as
specified in paragraph (b)(2)(i) of this section. Systems shall
demonstrate that all previous analytical results were less than \1/2\
MCL/AMCL. New systems and systems using a new ground water source must
complete four consecutive quarters of monitoring before the system is
eligible for a monitoring waiver; and
(B) States determine that the systems are reliably and consistently
below the MCL/AMCL, based on a consideration of potential radon
contamination of the source water due to the geological characteristics
of the source water aquifer.
(ii) Systems with a monitoring waiver must collect a minimum of 1
sample every nine-years (once per compliance cycle).
(iii) A monitoring waiver remains in effect until completion of the
nine-year compliance cycle.
(iv) A decision by States to grant a monitoring waiver shall be
made in writing and shall set forth the basis for the determination.
(4) Confirmation samples. Systems may take additional samples to
verify initial sample results as specified by the State. The results of
the initial and confirmation samples will be averaged for use in
calculation of compliance.
(5) Compliance. Compliance with Sec. 141.66 shall be determined
based on the analytical result(s) obtained at each sampling point. If
one sampling point is in violation, the system is in violation.
(i) For systems monitoring more frequently than annually,
compliance with the MCL/AMCL is determined by a running annual average
at each sampling point. If the average at any sampling point is greater
than the MCL/AMCL, then the system is out of compliance with the MCL/
AMCL.
(ii) If any one quarterly sampling result will cause the running
average to exceed the MCL/AMCL, the system is out of compliance.
(iii) Systems monitoring annually or less frequently whose sample
result exceeds the MCL/AMCL will revert to quarterly sampling
immediately. The system will not be considered in violation of the MCL/
AMCL until they have completed one year of quarterly sampling.
(iv) All samples taken and analyzed under the provisions of this
section must be included in determining compliance, even if that number
is greater than the minimum required.
(v) If a system does not collect all required samples when
compliance is based on a running annual average of

[[Page 59372]]

quarterly samples, compliance will be based on available data.
(vi) If a sample result is less than the detection limit, zero will
be used to calculate the annual average.
(vii) During the initial monitoring period, if the compliance
determination for a system in a non-MMM State exceeds the MCL, the
system will incur a MCL violation unless the system notifies the State
by [four years after date of publication of the final rule in the
Federal Register] of their intent to submit a local MMM plan, submits a
local MMM plan to the State within [5 years after date of publication
of the final rule in the Federal Register] and begins implementation by
[5.5 years after date of publication of the final rule in the Federal
Register]. The State shall approve or disapprove a local MMM program
plan within 6 months from the date of receipt. If the State does not
disapprove the local MMM program plan during such period, then the CWS
shall implement the plan submitted to the State for approval. The
compliance determination will be conducted as described in this
paragraph.
(viii) Following the completion of the initial monitoring period,
if the compliance determination for a system in a non-MMM State exceeds
the MCL, the system will incur a MCL violation unless the system
submits a local MMM plan to the State within 1 year from the date of
the exceedence and begins implementation 1.5 years from the date of the
exceedence. The State shall approve or disapprove a local MMM program
plan within 6 months from the date of receipt. If the State does not
disapprove the local MMM program plan during such period, then the CWS
shall implement the plan submitted to the State for approval. The
compliance determination will be conducted as described in this
paragraph.
(6) If a community water system has a distribution system separable
from other parts of the distribution system with no interconnections,
the State may allow the system to give public notice to only the area
served by that portion of the system which is out of compliance.
5. Section 141.28 is revised to read as follows:

Sec. 141.28 Certified laboratories.

(a) For the purpose of determining compliance with Sec. 141.20
through 141.27, 141.41, and 141.42, samples may be considered only if
they have been analyzed by a laboratory certified by the State except
that measurements for turbidity, free chlorine residual, temperature
and pH may be performed by any person acceptable to the State.
(b) Nothing in this part shall be construed to preclude the State
or any duly designated representative of the State from taking samples
or from using the results from such samples to determine compliance by
a supplier of water with the applicable requirements of this part.

Subpart F--[Amended]

6. A new Sec. 141.55 is added to Subpart F to read as follows:

Sec. 141.55 Maximum contaminant level goals for radionuclides.

MCLGs are as indicated in the following table:

------------------------------------------------------------------------
Contaminant MCLG
------------------------------------------------------------------------
Radon-222.................................... Zero.
------------------------------------------------------------------------

Subpart G--[Amended]

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

Sec. 141.66 Maximum contaminant level for radionuclides.

(a) The maximum contaminant level for radon-222 is as follows: (1)
A community water system (CWS) using a ground water source or using
ground water and surface water sources that serves 10,000 or fewer
people shall comply with the alternative maximum contaminant level
(AMCL) of 4000 pCi/L, and implement a State-approved multimedia
mitigation (MMM) program to address radon in indoor air (unless the
State in which the system is located has a MMM approved by the
Environmental Protection Agency). These systems may elect to comply
with the MCL of 300 pCi/L instead of developing a local CWS MMM program
plan.
(2) A CWS using a ground water source or using ground water and
surface water sources that serves more than 10,000 people shall comply
with the MCL of 300 pCi/L, except that the system may comply with an
AMCL of 4000 pCi/L where:
(i) The State in which the CWS is located has adopted an MMM
program plan approved by EPA; or,
(ii) The CWS has adopted an MMM program plan approved by the State.
(3) A CWS shall monitor for radon in drinking water according to
the requirements in Sec. 141.20, and report the results to the State,
and continue to monitor as described in Sec. 141.20. If the State
determines that the CWS is in compliance with the MCL of 300 pCi/L, the
CWS has met the requirements of this section and is not subject to the
requirements of subpart R of this part, regarding MMM programs.
(4) 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 radon identified in paragraphs (a)(1) and (a)(2) of this section:

BAT for Radon-222

High-Performance Aeration \1\

(5) The Administrator, pursuant to section 1412 of the Act, hereby
identifies in the following table the best technology available to
systems serving 10,000 persons or fewer for achieving compliance with
the MCL or AMCL. The table addresses affordability and technical
feasibility for such BAT.
---------------------------------------------------------------------------

\1\ High Performance Aeration is defined as the group of
aeration technologies that are capable of being designed for high
radon removal efficiencies, i.e., Packed Tower Aeration, Multi-Stage
Bubble Aeration and other suitable diffused bubble aeration
technologies, Shallow Tray and other suitable Tray Aeration
technologies, and any other aeration technologies that are capable
of similar high performance.

Proposed Small Systems Compliance Technologies (SSCTS) \1\ and Associated Contaminant Removal Efficiencies
----------------------------------------------------------------------------------------------------------------
Affordable for
Small systems compliance listed small Removal Operator level Limitations (see
technology systems efficiency required \3\ footnotes)
categories \2\
----------------------------------------------------------------------------------------------------------------
Packed Tower Aeration (PTA)... All Size 90->99.9% Removal Intermediate.......... (a)
Categories.
High Performance Package Plant All Size 90-> 99.9% Basic to Intermediate. (a)
Aeration (e.g., Multi-Stage Categories. Removal.
Bubble Aeration, Shallow Tray
Aeration).
Diffused Bubble Aeration...... All Size 70 to >99% Basic................. (a, b)
Categories. removal.

[[Page 59373]]

Tray Aeration................. All Size 80 to >90%....... Basic................. (a, c)
Categories.
Spray Aeration................ All Size 80 to >90%....... Basic................. (a, d)
Categories.
Mechanical Surface Aeration... All Size >90%............. Basic................. (a, e)
Categories.
Centralized granular activated May not be 50 to >99% Basic................. (f)
carbon. affordable, Removal.
except for very
small flows.
Point-of-Entry (POE) granular May be affordable 50 to >99% Basic................. (f, g)
activated carbon. for systems Removal.
serving fewer
than 500 persons.
----------------------------------------------------------------------------------------------------------------
\1\ Section 1412(b)(4)(E)(ii) of the SDWA specifies that SSCTs must be affordable and technically feasible for
small systems.
\2\ The Act (ibid.) specifies three categories of small systems: i) those serving 25 or more, but fewer than
501, ii) those serving more than 500, but fewer than 3,301, and iii) those serving more than 3,300, but fewer
than 10,001.
\3\ From National Research Council. Safe Water from Every Tap: Improving Water Service to Small Communities.
National Academy Press. Washington, DC. 1997. Limitations: a) Pre-treatment to inhibit fouling may be needed.
Post-treatment disinfection and/or corrosion control may be needed. b) May not be as efficient as other
aeration technologies because it does not provide for convective movement of the water, which reduces the
air:water contact. It is generally used in adaptation to existing basins. c) Costs may increase if a forced
draft is used. Slime and algae growth can be a problem, but may be controlled with chemicals, e.g., copper
sulfate or chlorine. d) In single pass mode, may be limited to uses where low removals are required. In
multiple pass mode (or with multiple compartments), higher removals may be achieved. e) May be most applicable
for low removals, since long detention times, high energy consumption, and large basins may be required for
larger removal efficiencies. f) Applicability may be restricted to radon influent levels below around 5000 pCi/
L to reduce risk of the build-up of radioactive radon progeny. Carbon bed disposal frequency should be
designed to allow for standard disposal practices. If disposal frequency is too long, radon progeny, radium,
and/or uranium build-up may make disposal costs prohibitive. Proper shielding may be required to reduce gamma
emissions from the GAC unit. GAC may be cost-prohibitive except for very small flows. g) When POE devices are
used for compliance, programs to ensure proper long-term operation, maintenance, and monitoring must be
provided by the water system to ensure adequate performance.

Subpart O--[Amended]

8. Section 141.151 is amended by revising paragraph (d) to read as
follows:

141.151 Purpose and applicability of this subpart.

* * * * *
(d) For the purpose of this subpart, detected means: at or above
the levels prescribed by Sec. 141.23(a)(4) for inorganic contaminants,
at or above the levels prescribed by Sec. 141.24(f)(7) for the
contaminants listed in Sec. 141.61(a), at or above the level prescribed
by Sec. 141.24(h)(18) for the contaminants listed in Sec. 141.61(c), at
or above the level prescribed by Sec. 141.66 for radon, and at or above
the levels prescribed by Sec. 141.25(c) for radioactive contaminants.
* * * * *
9. Section 141.153 is amended by revising paragraph (d)(1)(i);
removing paragraph (e)(2) and redesignating paragraph (e)(3) as (e)(2);
redesignating paragraphs (f)(5), (f)(6), and (f)(7) as (f)(6), (f)(7),
and (f)(8); and adding paragraph (f)(5) to read as follows:

Sec. 141.153 Content of the reports.

* * * * *
(d) * * *
(1) * * *
(i) Contaminants subject to a MCL, AMCL, action level, or treatment
technique (regulated contaminants);
* * * * *
(f) * * *
(5) Local multimedia radon mitigation programs prescribed by
subpart R of this part.
* * * * *
10. Section 141.154 is amended by adding paragraph (f) as follows:

Sec. 141.154 Required additional health information.

* * * * *
(f) In each complete calendar year between [date of publication of
final rule in the Federal Register] and [4 years after date of
publication of the final rule in the Federal Register], each report
from a system that has ground water as a source must include the
following notice (except that a system developing a local MMM program
in a non-MMM State needs to include this statement in each calendar
year between [date of publication of the final rule in the Federal
Register] and [5 years after date of publication of the final rule in
the Federal Register] :

Radon is a naturally-occurring radioactive gas found in soil and
outdoor air that may also be found in drinking water and indoor air.
Some people exposed to elevated radon levels over many years in
drinking water may have an increased risk of getting cancer. The
main health risk is lung cancer from radon entering indoor air from
soil under homes. Your water system plans to test for radon by
[insert date], and if radon is detected your water system will
provide the results of testing to their customers. The best way to
reduce the overall risk from radon is to reduce radon levels in
indoor air. Some States, and water systems, may now be working to
develop a program to reduce radon exposure in indoor air and
drinking water. To get more information and to help develop the
program, call the Radon Hotline (800-SOS-RADON) or visit the web
site http://www.epa.gov/iaq/radon/.

Subpart Q--[Amended]

11. In Sec. 141.201, Table 1 proposed on May 13, 1999, at 64 FR
25964 is amended by revising paragraphs (1) introductory text and
(1)(i) to read as follows:

Sec. 141.201 General Public Notification Requirements.

* * * * *
Table 1 to Sec. 141.201--Violation Categories and Other Situations
Requiring a Public Notice.
(1) NPDWR violations (MCL/AMCL, local MMM, MRDL, treatment
technique, monitoring and testing procedure)
(i) Failure to comply with an applicable maximum contaminant level
(MCL), alternative maximum contaminant level (AMCL), the local
multimedia mitigation requirement for small systems in non-MMM States,
or maximum residual disinfectant level (MRDL).
* * * * *
12. In Sec. 141.203, Table 1 proposed on May 13, 1999, at 64 FR
25964 is amended by revising paragraph (1) to read as follows:

Sec. 141.203 Tier 2 Public Notice--Form, manner, and frequency of
notice.

* * * * *

[[Page 59374]]

Table 1 to Sec. 141.203. Violation Categories and Other Situations
Requiring a Tier 2 Public Notice
(1) All violations of the MCL, AMCL, MRDL, and treatment technique
requirements not included in the Tier 1 notice category;
* * * * *
13. In Sec. 141.204, Table 1 proposed on May 13, 1999, at 64 FR
25964 is amended by adding paragraph (5) to read as follows:

Sec. 141.204. Tier 3 Public Notice--Form, manner, and frequency of
notice.

* * * * *
Table 1 to Sec. 141.204. Violation Categories and Other Situations
Requiring a Tier 3 Public Notice
(5) All violations of the MMM requirements not included in the Tier
1 or 2 notice category;
* * * * *
14. Section 141.205 proposed on May 13, 1999, at 64 FR 25964 is
amended by revising paragraph (d)(1), to read as follows:

Sec. 141.205 Content of the public notice.

* * * * *
(d) * * *
(1) Standard health effects language for MCL, AMCL, MMM or MRDL
violations, treatment technique violations, and violations of the
condition of a variance or exemption. Public water systems must include
in each public notice the health effects language specified in Appendix
B to this subpart corresponding to each MCL, AMCL, MMM, MRDL, and
treatment technique violation listed in Appendix A to this subpart, and
for each violation of a condition of a variance or exemption.
* * * * *
15. Part 141 is amended by adding a new Subpart R to read as
follows:

Subpart R--Reducing Radon Risks In Indoor Air and Drinking Water

Sec.

141.300 Applicability.
141.301 General requirements.
141.302 Multimedia mitigation (MMM) requirements (required elements
of MMM program plans).
141.303 Multimedia mitigation (MMM) reporting and compliance
requirements.
141.304 Local multimedia mitigation program plan approval and
program review.
141.305 States that do not have primacy.

Subpart R--Reducing Radon Risks in Indoor Air and Drinking Water

Sec. 141.300 Applicability.

(a) The requirements of this subpart constitute national primary
drinking water regulations for radon. The provisions of this subpart
apply to community water systems (CWS) using a ground water source or
using ground water and surface water sources. CWSs must monitor for
radon in drinking water according to the requirements described in
Sec. 141.20, and report the results to the State, and continue to
monitor as described in Sec. 141.20. If the State determines that the
CWS is in compliance with the MCL of 300 pCi/L, the CWS has met the
requirements of this section and is not subject to the requirements of
this subpart.
(b) These regulations in this subpart establish criteria for the
development and implementation of program plans to mitigate radon in
indoor air and drinking water (multimedia mitigation or MMM program
plan). In general, where a State, CWS, or Tribal MMM program plan is
approved, CWSs comply with an AMCL of 4000 pCi/L (Sec. 141.66). In
jurisdictions without an approved MMM program plan, large CWSs (serving
greater than 10,000 people) must comply with an MCL of 300 pCi/L
(Sec. 141.66), except they comply with the AMCL of 4000 pCi/L if they
develop a CWS MMM program plan approved by the State. Small community
water systems serving 10,000 or fewer people must comply with 4000 pCi/
L and implement a State-approved multimedia mitigation program plan to
address radon in indoor air (unless the State in which the system is
located has a multimedia mitigation program plan approved by the
Environmental Protection Agency); these systems have the option of
complying with the MCL instead of implementing a MMM program.

Sec. 141.301 General requirements.

(a) The requirements for the MMM program plan are set out in this
subpart. The requirements for the MCL are set out in Sec. 141.20(a)
(analytical methods), Sec. 141.20(b) (monitoring and compliance),
Sec. 141.66(a) through (c) (requirements for systems, including MCL and
AMCL), and Sec. 141.66(d) (BAT).
(b) Compliance dates.--(1) Initial monitoring. (i) For States that
submit a letter to the Administrator by [90 days after date of
publication of the final rule in the Federal Register] committing to
develop an MMM program plan in accordance with section
1412(b)(13)(G)(v) of the Act, CWSs must begin one year of quarterly
monitoring for compliance with the AMCL by [4.5 years after date of
publication of the final rule in the Federal Register].
(ii) For States not submitting a letter to the Administrator by [90
days after date of publication of final rule in the Federal Register]
committing to develop an MMM program plan, CWSs must begin one year of
quarterly monitoring for compliance with the MCL/AMCL by [3 years after
date of publication of final rule in the Federal Register].
(2) State-wide MMM programs. (i) For States that submit a letter to
the Administrator by [90 days after date of publication of the final
rule in the Federal Register] committing to develop an MMM program plan
in accordance with section 1412(b)(13)(G)(v), implementation of the
State-wide MMM program must begin by [4.5 years after date of
publication of the final rule in the Federal Register].
(ii) For States not submitting a letter to the Administrator by [90
days after date of publication of the final rule in the Federal
Register] committing to develop an MMM program plan, but which
subsequently decide to adopt the AMCL, implementation of the State-wide
MMM program must begin by [3 years after date of publication of the
final rule in the Federal Register].
(iii) If EPA-approval of a State MMM program plan is revoked, all
systems have one year from notification by the State to comply with the
MCL. If a system chooses to continue complying with the AMCL and
develop and implement a local MMM program, the State will specify a
timeframe for compliance.
(3) Local MMM programs. (i) During the initial monitoring period,
if the compliance determination for a CWS in a non-MMM State exceeds
the MCL, the CWS will incur an MCL violation unless the system notifies
the State by [four years after date of publication of the final rule in
the Federal Register] of their intent to submit a local MMM plan,
submits a local MMM plan to the State within [5 years after date of
publication of the final rule in the Federal Register] and begins
implementation by [5.5 years after date of publication of the final
rule in the Federal Register]. The compliance determination will be
conducted as described in Sec. 141.20(b)(2).
(ii) Following the completion of the initial monitoring period, if
the compliance determination for a CWS in a non-MMM State exceeds the
MCL, the system will incur an MCL violation unless the system submits a
local MMM plan to the State within 1 year from the date of the
exceedence and begins implementation 1.5 years from the date of the
exceedence. The compliance determination will be conducted as described
in this paragraph.
(iii) The State shall approve or disapprove a local MMM program
plan

[[Page 59375]]

within 6 months from the date of receipt. If the State does not
disapprove the local MMM program plan during such period, the CWS shall
implement the plan submitted to the State for approval.
(iv) If the State determines the CWS is not adequately implementing
the local MMM plan approved by the State, the system shall incur an MMM
violation.
(v) During the MMM program 5-year review periods, the system shall
incur an MMM violation if the State determines the CWS is not meeting
MMM program plan objectives.

Sec. 141.302 Multimedia mitigation (MMM) requirements (required
elements of MMM program plans).

The following are required for approval of State MMM program plans
by EPA. Local MMM program plans developed by community water systems
(CWS) are deemed to be approved by EPA if they meet these criteria (as
appropriate for the local level) and are approved by the State. The
term ``State'', as referenced next, means any entity submitting an MMM
program plan for approval, including States, with and without primacy,
Indian Tribes and community water systems.
(a) Description of process for involving the public. (1) States are
required to involve community water system customers, and other sectors
of the public with an interest in radon, both in drinking water and in
indoor air, in developing their MMM program plan. The MMM program plan
must include:
(i) A description of processes the State used to provide for public
participation in the development of its MMM program plan, including the
components identified in paragraphs (b), (c), and (d) of this section;
(ii) A description of the nature and extent of public participation
that occurred, including a list of groups and organizations that
participated;
(iii) A summary describing the recommendations, issues, and
concerns arising from the public participation process and how these
were considered in developing the State's MMM program plan; and
(iv) A description of how the State made information available to
the public to support informed public participation, including
information on the State's existing indoor radon program activities and
radon risk reductions achieved, and on options considered for the MMM
program plan along with any analyses supporting the development of such
options.
(2) Once the draft program plan has been developed, the State must
provide notice and opportunity for public comment on the draft plan
prior to submitting it to EPA.
(b) Quantitative goals. (1) States are required to establish and
include in their plans quantitative goals, to measure the effectiveness
of their MMM program, for the following:
(i) Existing houses with elevated indoor radon levels that will be
mitigated by the public; and
(ii) New houses that will be built radon-resistant by home
builders.
(2) These goals must be defined quantitatively either as absolute
numbers or as rates. If goals are defined as rates, a detailed
explanation of the basis for determining the rates must be included.
(3) States are required to establish goals for promoting public
awareness of radon health risks, for testing of existing homes by the
public, for testing and mitigation of existing schools, and for
construction of new public schools to be radon-resistant, or to include
an explanation of why goals were not established in these program
areas.
(c) Implementation Plans. (1) States are required to include in
their MMM program plan implementation plans outlining the strategic
approaches and specific activities the State will undertake to achieve
the quantitative goals identified in paragraph (b) of this section.
This must include implementation plans in the following two key areas:
(i) Promoting increased testing and mitigation of existing housing
by the public through public outreach and education and during
residential real estate transactions.
(ii) Promoting increased use of radon-resistant techniques in the
construction of new homes.
(2) If a State has included goals for promoting public awareness of
radon health risks; promoting testing of existing homes by the public;
promoting testing and mitigation of existing schools; and promoting
construction of new public schools to be radon resistant, then the
State is required to submit a description of the strategic approach
that will be used to achieve the goals.
(3) States are required to provide the overall rationale and
support for why their proposed quantitative goals identified in
paragraph (b) of this section, in conjunction with their program
implementation plans, will satisfy the statutory requirement that an
MMM program be expected to achieve equal or greater risk reduction
benefits to what would have been expected if all community water
systems in the State complied with the MCL.
(d) Plans for measuring and reporting results. (1) States are
required to include in the MMM plan submitted to EPA a description of
the approach that will be used to assess the results from
implementation of the State MMM program, and to assess progress towards
the quantitative goals in paragraph (b) of this section. This
specifically includes a description of the methodologies the State will
use to determine or track the number or rate of existing homes with
elevated levels of radon in indoor air that are mitigated and the
number or the rate of new homes built radon-resistant. This must also
include a description of the approaches, methods, or processes the
State will use to make the results of these assessments available to
the public.
(2) If a State includes goals for promoting public awareness of
radon health risks; testing of existing homes by the public; testing
and mitigation of existing schools; and construction of new public
schools to be radon-resistant; the State is required to submit a
description of how the State will determine or track progress in
achieving each of these goals. This must also include a description of
the approaches, methods, or processes the State will use to make these
results of these assessments available to the public.

Sec. 141.303 Multimedia mitigation (MMM) reporting and compliance
requirements.

(a) In accordance with the Safe Drinking Water Act (SDWA), EPA is
to review State MMM programs at least every five years. For the
purposes of this review, the States with EPA-approved MMM program plans
shall provide written reports to EPA in the second and fourth years
between initial implementation of the MMM program and the first 5-year
review period, and in the second and fourth years of every subsequent
5-year review period. States that submit a letter to the Administrator
by [90 days after date of publication of the final rule in the Federal
Register] committing to develop an MMM program plan, must submit their
first 2-year report by 6.5 years from publication of the final rule.
For States not submitting the 90-day letter, but choosing subsequently
to submit an MMM program plan and adopt the AMCL, the first 2-year
report must be submitted to EPA by 5 years from publication of the
final rule. EPA will review these programs to determine whether they
continue to be expected to achieve risk reduction of indoor radon using
the information provided in the two biennial reports.
(b)(1) These reports are required to include the following
information:

[[Page 59376]]

(i) A quantitative assessment of progress towards meeting the
required goals described in Sec. 141.302(b), including the number or
rate of existing homes mitigated and the number or rate of new homes
built radon-resistant since implementation of the States' MMM program,
and,
(ii) A description of accomplishments and activities that implement
the required program strategies, described in Sec. 141.302(c), outlined
in the implementation plans and in the two required areas of promoting
increased testing and mitigation of existing homes and promoting
increased use of radon-resistant techniques in construction of new
homes.
(2) If goals were defined as rates, the State must also provide an
estimate of the number of mitigations and radon-resistant new homes
represented by the reported rate increase for the two-year period.
(3) If the MMM program plan includes goals for promoting public
awareness of the health effects of indoor radon, testing of homes by
the public; testing and mitigation of existing schools; and
construction of new public schools to be radon-resistant, the report is
also required to include information on results and accomplishments in
these areas.
(c) If EPA determines that a MMM program is not achieving progress
towards its goals, EPA and the State shall collaborate to develop
modifications and adjustments to the program to be implemented over the
five year period following the review. EPA will prepare a summary of
the outcome of the program evaluation and the proposed modification and
adjustments, if any, to be made by the State.
(d) If EPA determines that a State MMM program is not achieving
progress towards its MMM goals, and the State repeatedly fails to
correct, modify and adjust implementation of their MMM program after
notice by EPA, EPA will withdraw approval of the State's MMM program
plan. CWSs in the State would then be required to comply with the MCL,
or develop a State-approved CWS MMM program plan. The State will be
responsible for notifying CWSs of the Administrator's withdrawal of
approval of the State-wide MMM program plan. EPA will work with the
State to establish a State process for review and approval of CWS MMM
program plans that meet the required criteria, including local public
participation in development and review of the program plan, and a time
frame for submission of program plans by CWSs that choose to continue
complying with the AMCL.
(e) States shall make available to the public each of these two-
year reports identified in paragraph (a) of this section, as well as
the EPA summaries of the five-year reviews of a State's MMM program,
within 90 days of completion of the reports and the review.
(f) In primacy States without a State-wide MMM program, the States
shall provide a report to EPA every five-years on the status and
progress of CWS MMM programs towards meeting their goals. The first of
such reports would be due by [10.5 years after date of publication of
the final rule in Federal Register].

Sec. 141.304 Local multimedia mitigation program plan approval and
program review.

(a) In States without an EPA-approved MMM program plan, any
community water system may elect to develop and implement a local MMM
program plan that meets the criteria in Sec. 141.302 and comply with
the AMCL in lieu of the MCL. Local CWS MMM program plans must be
approved by the State.
(b) CWSs with State-approved MMM program plans shall report to the
State as required by the State. States shall review such local programs
at least every five years to determine if CWSs are implementing their
program plans and making progress towards their goals. If the CWS fails
to meet those requirements, the State shall require the system to
comply with the MCL.

Sec. 141.305 States that do not have primacy.

(a) If a State, as defined in section 1401 of the Act, that does
not have primary enforcement responsibility for the Public Water System
Program under section 1413 of the Act chooses to submit an MMM program
plan to EPA, that program plan must meet the criteria in Sec. 141.301.
EPA will approve such program plans in accordance with the requirements
of Sec. 141.302.
(b) States with EPA-approved MMM program plans shall report to EPA
in accordance with the requirements of Sec. 141.303.

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.

2. Section 142.12 is amended by adding new paragraph (b)(4) to read
as follows:

Sec. 142.12 Revision of State programs.

* * * * *
(b) * * *
(4) To be granted an extension for radon regulatory requirements
included under 40 CFR part 141, subpart R, the State must commit to
adopt the AMCL and MMM program plan, or MCL.
* * * * *
3. Section 142.15 is amended by adding new paragraph (c)(6) to read
as follows:

Sec. 142.15 Reports by States.

* * * * *
(c) * * *
(6) In accordance with the Safe Drinking Water Act (SDWA), EPA is
to review State MMM programs at least every five years. EPA will review
these programs to determine whether they continue to be expected to
achieve risk reduction of indoor radon using the information provided
in the two biennial reports. For the purposes of this review:
(i)(A) States with EPA-approved MMM program plans shall provide
written reports to EPA in the second and fourth years between initial
implementation of the MMM program and the first 5-year review period,
and in the second and fourth years of every subsequent 5-year review
period.
(B) States that submit a letter to the Administrator by [90 days
after date of publication of the final rule in the Federal Register]
committing to develop an MMM program plan, must submit their first 2-
year report by [6.5 years after date of publication of the final rule
in the Federal Register]. For States not submitting the 90-day letter,
but choosing subsequently to submit an MMM program plan and adopt the
AMCL, the first 2-year report must be submitted to EPA by [5 years
after date of publication of the final rule in the Federal Register].
(ii) These reports are required to include the following
information:
(A) A quantitative assessment of progress towards meeting the
required goals described in Sec. 141.302(b), including the number or
rate of existing homes mitigated and the number or rate of new homes
built radon-resistant since implementation of the States' MMM program,
and
(B) A description of accomplishments and activities that implement
the required program strategies, described in Sec. 141.302(c), outlined
in the implementation plans and in the two required areas of promoting
increased testing and mitigation of existing homes and promoting
increased use of radon-resistant techniques in construction of new
homes.
(C) If goals were defined as rates, the State must also provide an
estimate of

[[Page 59377]]

the number of mitigations and radon-resistant new homes represented by
the reported rate increase for the two-year period.
(D) If the MMM program plan includes goals for promoting public
awareness of the health effects of indoor radon, testing of homes by
the public; testing and mitigation of existing schools; and
construction of new public schools to be radon-resistant, the report is
also required to include information on results and accomplishments in
these areas.
(iii) States shall make available to the public each of these two-
year reports, as well as the EPA summaries of the five-year reviews of
a State's MMM program, within 90 days of completion of the reports and
the review.
(iv) In primacy States without a State-wide MMM program, the States
shall provide a report to EPA every five-years on the status and
progress of CWS MMM programs towards meeting their goals. The first of
such reports would be due by [10.5 years after date of publication of
the final rule in the Federal Register].
* * * * *
4. Section 142.16 is amended by adding new paragraph (i) to read as
follows:

Sec. 142.16 Special primacy requirements.

* * * * *
(i) Requirements for States to adopt 40 CFR part 141, subpart R. In
addition to the general primacy requirements elsewhere in this part,
including the requirement that State regulations be at least as
stringent as federal requirements, an application for approval of a
State program revision that adopts 40 CFR part 141, subpart R, must
contain a description of how the State will accomplish the program
requirements for implementation of the AMCL and MMM program plan or the
MCL as follows:
(1) If a State chooses to develop and implement a State-wide MMM
program plan and adopt the AMCL, the primacy application must include
the following elements:
(i) A copy of the State-wide MMM program plan prepared to meet the
criteria outlined in Sec. 141.302 of this chapter.
(ii) A description of how the State will make resources available
for implementation of the State-wide MMM program plan.
(iii) A description of the extent and nature of coordination
between interagency programs (i.e., indoor radon and drinking water
programs) on development and implementation of the MMM program plan,
including the level of resources that will be made available for
implementation and coordination between interagency programs (i.e.,
indoor air and drinking water programs).
(2) If a State chooses to adopt the MCL the primacy application
must contain the following:
(i) A description of how the State will implement a program to
approve local CWS MMM program plans prepared to meet the criteria
outlined in Sec. 141.302 of this chapter and a description of the
State's authority to implement this program.
(ii) A description of how the State will ensure local CWS MMM
program plans are implemented.
(iii) A description of reporting and record keeping requirements
for local CWS MMM programs.
(iv) A description of how the State will review local CWS program
plans at least every five years to determine if they are implementing
the MMM program and making progress towards their goals.
(v) A description of the procedures and schedule the State will use
in withdrawing State approval of a CWS MMM program plan and notifying
the CWS that they are required to comply with the MCL.
(vi) A description of the extent and nature of coordination between
interagency programs (i.e., indoor radon and drinking water programs)
on development and implementation of the State process for review and
approval of CWS MMM program plans. This description includes the level
of resources that will be made available for implementation and
coordination between interagency programs (i.e., indoor air and
drinking water programs).
(vii) A description of how the State will make required CWS reports
available to the public.
5. A new Sec. 142.65 is added to subpart G, to read as follows:

Sec. 142.65. Variances and exemptions from the maximum contaminant
level for radon.

(a) The Administrator, pursuant to section 1415(a)(1)(A) of the
Act, hereby identifies in the following table as the best technology,
treatment techniques, or other means available for achieving compliance
with the maximum contaminant level for radon:
BAT for Radon-222
1. For all systems: High-Performance Aeration \1\
2. For systems serving 10,000 persons or fewer: High-Performance
Aeration \1\ or \2\, Granular Activated Carbon \2\ (GAC), and Point-of-
Entry GAC \2\.
---------------------------------------------------------------------------

(b) A State shall require a community water system to install and/
or use any treatment method identified in paragraph (a) of this section
as a condition for granting a variance, based upon an evaluation
satisfactory to the State that indicates that alternative sources of
water are not reasonably available to the system.
(c) Bottled water and/or granular activated carbon point-of-use
devices cannot be used as means of being granted a variance or an
exemption for radon.
(d) Community water systems that use point-of-entry devices as a
condition for obtaining a variance or an exemption from NPDWRs must
meet the following requirements:
(1) All point-of-entry units shall be owned, controlled, and
maintained by the community water system or by a person or persons
under contract with the public water system to ensure proper operation
and maintenance of the unit under the terms of the variance or
exemption.
(2) All point-of-entry units shall be equipped with mechanical
warning devices to ensure that customers are notified of operational
problems.
(3) If the American National Standards Institute has issued product
standards applicable to a specific type of point-of-entry device for
radon,

[[Page 59378]]

individual units of that type shall not be accepted under the terms of
the variance or exemption unless they are independently certified in
accordance with such standards.
(4) Before point-of-entry devices are installed, the community
water system must obtain the approval of a monitoring plan which
ensures that the devices provide health protection equivalent to
analogous centralized water treatment.
(5) The community water system must apply effective technology
under a State-approved plan. The microbiological safety of the water
must be maintained at all times.
(6) The State must require adequate certification of performance,
field testing, and, if not included in the certification process, a
rigorous engineering review of the point-of-entry devices.
(7) The design and application of point-of-entry devices must
consider the potential for increasing concentrations of heterotrophic
bacteria in water treated with activated carbon. It may be necessary to
use frequent backwashing, post-GAC contactor disinfection, and
Heterotrophic Plate Count monitoring to ensure that the microbiological
safety of the water is not compromised.
6. Section 142.72 is amended by removing the introductory text, by
redesignating paragraphs (a) through (d) as (b)(1) through (b)(4), and
by adding a new paragraph (a) to read as follows:

Sec. 142.72. Requirements for Tribal eligibility.

(a) If a Tribe meets the criteria in paragraph (b) of this section,
the Administrator is authorized to treat an Indian Tribe as eligible to
apply for:
(1) Primary enforcement responsibility for the Public Water System
Program:
(2) Authority to waive the mailing requirements of 40 CFR
141.155(a); and
(3) Authority to develop and implement a radon multimedia
mitigation program in accordance with 40 CFR part 141, subpart R.
* * * * *
7. Section 142.78 is amended by revising paragraph (b) to read as
follows:

Sec. 142.78. Procedure for processing an Indian Tribe's application.

* * * * *
(b) A Tribe that meets the requirements of Sec. 142.72 is eligible
to apply for development grants and primary enforcement responsibility
for a Public Water System and associated funding under section 1443(a)
of the Act, for primary enforcement responsibility for public water
systems under section 1413 of the Act, for the authority to waive the
mailing requirements of 40 CFR 141.155(a), and for the authority to
develop and implement a radon multimedia mitigation program in
accordance with 40 CFR part 141, subpart R.
8. Part 142 is amended by adding a new Subpart L to read as
follows:

Subpart L--Review of State MMM Programs

Sec. 142.400 Review of State MMM programs and procedures for
withdrawing approval of State MMM programs.

(a)(1)At least every five years, the Administrator shall review
State MMM programs. For the purposes of this review, States with EPA-
approved MMM programs shall provide written reports to the
Administrator in the second and fourth years between initial
implementation of the MMM program and the first 5-year review period,
and in the second and fourth years of every subsequent 5-year review
period. The written reports will discuss the status and progress of
their program towards meeting their MMM goals. The Administrator will
use the information provided in the two biennial reports in discussions
and consultations with the State to review the programs to determine
whether they continue to be expected to achieve risk reduction of
indoor radon.
(2) If the Administrator determines that a State MMM program is not
achieving progress towards its MMM goals, the Administrator and the
State shall collaborate to develop modifications and adjustments to the
program to be implemented over the five year period following the
review. EPA will prepare a summary of the outcome of the program
evaluation and the proposed modification and adjustments, if any, to be
made by the State.
(3) If the State repeatedly fails to correct, modify or adjust
implementation of its MMM program after notice by the Administrator,
the Administrator shall initiate proceedings to withdraw approval of
the State's MMM program plan. The Administrator shall notify the State
in writing that EPA is initiating withdrawing a State-wide MMM program
plan and shall summarize in the notice the information available that
indicates that the State is no longer achieving progress towards its
MMM goals.
(4) The State notified pursuant to paragraph (a)(3) of this section
may, within 30 days of receiving the Administrator's notice, submit to
the Administrator evidence that the State plans to implement
modifications to the State MMM program.
(5) After reviewing the submission of the State, if any, made
pursuant to paragraph (a)(4) of this section, the Administrator shall
make a final determination either that the State no longer continues to
achieve progress towards its MMM goals, or that the State continues to
implement modifications to the State MMM program, and shall notify the
State of his or her determination. Before a final determination that
the State no longer continues to achieve progress towards its MMM
goals, the Administrator shall offer a public hearing and will publish
a notice in the Federal Register.
(b) If approval of a State's MMM program is withdrawn, the State
will be responsible for notifying CWSs of the Administrator's
withdrawal of approval of the State-wide MMM program plan. The CWSs in
the State would then be required to comply with the MCL. EPA will work
with the State to establish a State process for review and approval of
CWS MMM program plans that meet the required criteria and a time frame
for submittal of program plans by CWSs that choose to continue
complying with the AMCL. The review process will allow for local public
participation in development and review of the program plan.

[FR Doc. 99-27741 Filed 10-25-99; 3:12 pm]
BILLING CODE 6560-50-P

Notices For
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[[pp. 59345-59378]] National Primary Drinking Water Regulations; Radon-222

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