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

Federal Register Document

Related Material









[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]                         



 



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







[[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







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Primary Drinking Water Regulation: Radon, Washington, D.C. 



[September 1998] [USEPA 1998c]



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Air. Health Risks from Low-Level Environmental Exposure to 



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Criteria Under the 1996 Amendments to the Safe Drinking Water Act. 



Final Draft Report. Prepared by International Consultants, Inc. for 



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Technology Findings for Contaminants Regulated before 1996. EPA 815-



R-98-003. Washington, D.C. [September 1998] [USEPA 1998f]



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System Compliance Options: Point-of-Use and Point-of-Entry Treatment 



Units. Prepared by the Cadmus Group for EPA. [September 1998] [USEPA 



1998g]



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Water Treatment Cost Upgrades. Prepared by Science Applications 



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1996. EPA 815-R-98-002. [September 1998] [USEPA 1998i]



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Drinking Water. Evaluation of Full-Scale Treatment Technologies at 



Small Drinking Water Systems: Summary of Available Cost and 



Performance Data. [December 1998] [USEPA 1998j]



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Treatment Options as Small System Treatment Technologies. Prepared 



by Science Applications International Corporation for EPA. [January 



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Technology. Draft Criteria Document for Radon in Drinking Water. 



Washington, DC. [July 1999] [USEPA 1999b]



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Water Contaminants. Primary and Secondary Constituents, with two 



sets of appendices:







[[Page 59362]]







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Removal of Radon from Drinking Water. Prepared by SAIC for EPA. [May 



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the Health Risk Reduction from EPA's Indoor Radon Program. Brian 



Gregory, Office of Radiation and Indoor Air. Washington, DC. [May 



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Gas Emissions and Associated Fatal Cancer Risks for Various Radon 



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of Ground Water and Drinking Water, [May 12, 1999] [USEPA 1999j]



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for Preparing Economic Analyses (Draft). [June 11, 1999] [USEPA 



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Incorporated for EPA, Office of Ground Water and Drinking Water 



[August 6, 1999] [USEPA 1999l]



U.S. Environmental Protection Agency, Office of Ground Water and 



Drinking Water. An Analysis of the Potential Benefits and Costs of 



Radon in Drinking Water for Non-Transient, Non-Community Water 



Systems (NTNCWS). [August 1999] [USEPA 1999m]



Viscusi, W.K., W.A. Magat, and J. Huber. Pricing Environmental 



Health Risks: Survey Assessments of Risk-Risk and Risk-Dollar Trade-



Offs for Chronic Bronchitis. Journal of Environmental Economics and 



Management, 21:32-51 [1991] [Viscusi 1991]



Wade Miller Associates, Inc., Occurrence and Exposure Assessment for 



Radon in Public Water Supplies, prepared for EPA Office of Drinking 



Water [September 25, 1990] [Wade Miller 1990]



Wade Miller Associates, Inc., Addendum to Occurrence and Exposure 



Assessment for Radon, Radium 226, Radium 228, Uranium, and Gross 



Alpha Particle Activity in Public Water Supplies, (Revised 



Occurrence Estimate Based on Comments to the Proposed Radionuclides 



Regulations), Final Draft, prepared for EPA Office of Drinking Water 



[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.)







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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\.



---------------------------------------------------------------------------







    \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.



    \2\ As defined and described in 40 CFR 141.66 (e).



---------------------------------------------------------------------------







    (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

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