United States
Environmental Protection
Agency
Office of Water
4607
EPA 815-D-99-002
November 1999
REGULATORY IMPACT ANALYSIS
AND REVISED HEALTH RISK
REDUCTION AND COST
ANALYSIS FOR RADON IN
DRINKING WATER
PUBLIC COMMENT DRAFT
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REGULATORY IMPACT ANALYSIS AND HEALTH RISK REDUCTION AND
COST ANALYSIS FOR RADON IN DRINKING WATER
Table of Contents
1. EXECUTIVE SUMMARY
2. INTRODUCTION
2.1 Background
2.2 Regulatory History
2.3 Economic Rationale
2.3.1 Statutory Authority for Promulgating the Rule
2.3.2 The Economic Rationale for Regulation
2.4 Safe Drinking Water Act Amendments of 1996
2.5 Specific Requirements for the Health Risk Reduction and Cost Analysis
2.6 Document Structure
3. HEALTH EFFECTS FROM RADON EXPOSURE
3.1 Radon Occurrence and Exposure Pathways
3.1.1 Occurrence
3.1.2 Exposure Pathways
3.2 Nature of Health Impacts
3.3 Impacts on Sensitive Subpopulations '
3.4 Risk Reduction Model for Radon in Drinking Water
3.5 Risks from Existing Radon Exposures
3.6 Potential for Risk Reductions Associated with Removal of Co-Occurring
Contaminants
3.7 Potential for Risk Increases from Other Contaminants Associated with Radon
Removal
3 8 Risk for Ever-Smokers and Never-Smokers
4. CONSIDERATION OF REGULATORY ALTERNATIVES
4.1 Radon Levels Evaluated
4.2 Selected Regulatory Alternatives
4.2.1 Requirements for Small Systems Serving 10,000 People or Less
4.2.2 Requirements for Large Systems Serving More Than 10,000 People
4.2.3 Background on the Selection of the MCL and AMCL
5. BASELINE ANALYSIS
5.1 Industry Profile ;
5.1.1 Numbers and Sizes of Systems
5.1.2 Numbers of Sources Per System
5.2 Baseline Assumptions
5.2.1 Distribution of Radon in Groundwater Systems
5.2.2 Water Treatment Technologies Currently in Place
5.3 Baseline Benefits Analysis
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6. BENEFITS ANALYSIS
6.1 Nature of Regulatory Impacts
6.1.1 Quantifiable Benefits
6.1.2 Non-Quantifiable Benefits
6.2 Monetization of Benefits
6.2.1 Estimation of Fatal and Non-Fatal Cancer Risk Reduction
6.2.2 Value of Statistical Life for Fatal Cancers Avoided
6.2.3 Costs of Illness and Lost Time for Non-Fatal Cancers
6.2.4 Willingness to Pay to Avoid Non-Fatal Cancers
7. COST ANALYSIS OF COMPLIANCE WITH AN MCL
7.1 Total National Costs of Compliance
7.1.1 How Costs Were Developed
7.1.2 Benefit-Cost Determination
7.2 Drinking Water Treatment Technologies and Costs
7.2.1 Aeration
7.2.2 Granular Activated Carbon (GAC)
7.2.3 Storage
7.2.4 Regionalization
7.2.5 Costs of Achieving Radon Removal Efficiencies
7.2.6 Pre-Treatment to Reduce Iron and Manganese Levels
7.2.7 Post-Treatment -- Disinfection
7.3 Monitoring Costs
7.4 Cost of Technologies as a Function of Flow Rates and Radon Removal Efficiency
7.5 Choice of Treatment Responses
7.6 Cost Estimation
7.6.1 Site and System Costs
7.6.2 Aggregate National Costs
7.6.3 Costs to Community Water Systems
7.6.4 Costs to Consumers/Households
7.6.5 Mixed Systems
7.7 Application of Radon Related Costs to Other Rules
8. ECONOMIC IMPACT ANALYSIS
8.1 Impacts on Governments and Small Business Units
8.1.1 Unfunded Mandates Reform Act
8.1.1.1 Cost-Benefit Analysis
8.1.1.2 Estimates of Future Compliance Costs and Disproportionate
Budgetary Effects
8.1.1.3 Macroeconomic Effects
8.1.1.4 Summary of EPA's Consultation with State, Local, and Tribal
Governments and Their Concerns
8.1.1.5 Nature of State, Local, and Tribal Government Concerns and How
EPA Addressed These Concerns
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8.1.1.6 Regulatory Alternatives Considered
8.1.1.7 Impacts on Small Governments
8.1.2 Indian Tribal Governments
8.1.3 Regulatory Flexibility Act / Small Business Regulatory Enforcement
Fairness Act
8.1.3.1 Use of Alternative Small Entity. Definition
8.1.3.2 Background and Analysis
8.1.3.3 Number of Small Entities Affected
8.1.3.4 Proposed Rule Reporting Requirements for Small Systems
8.1.3.5 Significant Regulatory Alternatives and SBAR Panel
Recommendations
8.1.4 Paperwork Reduction Act
8.1.4.1 Summary of Information Collection Requirements
8.2 Impacts on Subpopulations
8.3 Environmental Justice
9. RESULTS: WEIGHING THE COSTS AND BENEFITS OF THE PROPOSED RULE
9.1 Multimedia Mitigation Programs for Radon Risk Reduction
9.2 Implementation Scenarios
9.3 Multimedia Mitigation Cost and Benefit Assumptions
9.3.1 Health Benefits
9.3.2 Radon Mitigation Costs
9.4 Costs and Benefits of Multimedia Mitigation Program Implementation
9.4.1 System-Level and State Costs
9.4.2 Benefit-Cost Ratios and Net Benefits of MMM Scenarios
9.4.3 Household Costs
9.4.4 Cost Per Fatal Cancer Avoided
10. COSTS AND BENEFITS OF 100 PERCENT COMPLIANCE WITH AN MCL
10.1 Overview of Analytical Approach
10.2 Health Risk Reduction and Monetized Health Benefits
10.3 Costs of Radon Mitigation
10.3.1 Aggregate Costs of Water Treatment
10.4 Costs to Community Water Systems
10.5 Costs and Impacts to Households
10.6 Incremental Costs and Benefits
10.7 Costs Per Life Saved
10.8 Uncertainty in Benefit and Cost Estimates
10.8.1 Uncertainties in Risk Reduction Estimates
10.8.2 Sensitivity of Benefits Estimates to Variability in the Value of Statistical
Life
10.8.3 Variability in Mitigation Cost Input Variables
10.8.4 Relative Contributions of Model Inputs to Mitigation Cost Variability
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Appendix A. Equations and Parameter Values Used in the Assessment of Risks and Risk
Reduction Benefits
Appendix B. Cost Curves for Radon Reduction and Disinfection Technologies
Appendix C. Flow Estimation Equations for Public and Private Water Systems
Appendix D. Summary Cost Tables
Appendix E. MMM Scenario Cost and Benefit Tables
Appendix F. NTNCWS Cost and Benefit Tables
List of Tables and Figures
Table 3-1. Radon Distributions by Region
Table 3-2. Radon Distribution in Public Water Systems
Table 3-3. Population Exposed Above Various Radon Levels By System Size
Table 3-4. Estimated Radon Unit Lifetime Fatal Cancer Risks in Community Water Systems
Table 3-5. Radon Treatment Assumptions to Calculate Residual Fatal Cancer Risks
Table 3-6. Annual Fatal Cancer Risks for Exposures to Radon from Community Water
Systems
Table 3-7. Radon Risk Reductions Across Various Effluent Levels and Percent Removals
Table 3-8. Radon Risk Reduction from Treatment Compared to DBP Risks
Table 3-9. Annual Lung Cancer Death Risks Estimates from Radon Progeny for Ever-
Smokers, Never-Smokers, and the General Population
Table 5-1. Number of Community Groundwater Systems in the United States
Table 5-2. Estimated Average Number of Wells Per Groundwater System
Table 5-3. Distribution of Radon Levels in U.S. Groundwater Sources
Table 5-4. Estimated Proportions of Groundwater Systems With Water Treatment
Technologies Already in Place
Table 6-1. Proportion of Fatal Cancers by Exposure Pathway and Estimated Mortality
Table 6-2. Estimated Medical Care and Lost-Time Costs Per Case for Survivors of Lung
Cancer
Table 6-3. Estimated Medical Care and Lost-time Costs Per Case for Survivors of Stomach
Cancer
Table 7-1. Summary of Estimated Water Mitigation Costs Under the Proposed Radon Rule
Table 7-2. Unit Treatment Costs by Removal Efficiency and System Size
Table 7-3. Technology Selection "Decision Tree" for Radon Mitigation Technologies
Table 8-1. Annual Water Mitigation and MMM Program Costs to Small Systems
Table 8-2. Administrative Costs to Community Water Systems Associated with Water
Mitigation and System-Level MMM Programs
Table 8-3. State Administrative Costs for Water Mitigation and MMM Programs
Table 8-4. Administrative Costs to Community Water Systems Associated with Water
Mitigation and System-Level MMM Programs (Annualized Over 20 Years)
Table 8-5. State Administrative Costs for Water Mitigation and MMM Programs
(Annualized Over 20 Years)
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Table 9-1 Summary ofMMM Scenario Assumptions
Table 9-2. Annual System-Level and State-Level Costs Associated With the Multimedia
Mitigation and AMCL Option
Table 9-3. Ratio of Benefits and Costs (System-Level) By System Size for Each Scenario
Table 9-4. Net Benefits By System Size for Each Scenario
Table 9-5. Costs Per Household By System Size for Each Scenario
Table 9-6. Cost Per Fatal Cancer Avoided By System Size for Each Scenario
Table 10-1. Risk Reduction and Residual Cancer Risk from Reducing Radon in Drinking
Water . , . „.
Table 10-2. Estimated Monetized Health Benefits from Reducing Radon in Drinking Water
Table 10-3. Risk Reduction and Monetized Benefits Estimates For Ever-Smokers
Table 10-4. Risk Reduction and Monetized Benefits Estimates For Never-Smokers
Table 10-5. Estimated Annualized National Costs of Reducing Radon Exposures Assuming
100% Compliance With an MCL
Table 10-6. Capital and O&M Costs of Mitigating Radon in Drinking Water
Table 10-7. Number of Community Groundwater Systems With One or More Sources
Exceeding Maximum Radon Levels ;
Table 10-8. Average Annual Cost Per System
Table 10-9. Annual Radon Mitigation Costs per Household for Community Water Systems to
Treat to Various Radon Levels
Table 10-10. Per Household Impact by Community Groundwater System as a Percentage of
Median Household Income
Table 10-11. Estimates of the Annual Incremental Risk Reduction, Costs, and Benefits of
Reducing Radon in Drinking Water Assuming 100% Compliance With an MCL
Table 10-12. Incremental Risk Reduction, Costs, and Monetized Health Benefits for Ever-
Smokers
Table 10-13. Incremental Risk Reduction, Costs, and Monetized Health Benefits for Never-
Smokers
Table 10-14. Total Costs per Fatal Cancer Avoided as a Function of Radon Level For 100%
Compliance With an MCL
Table 10-15. Total Annual Costs For 100% Compliance with an MCL and Fatal Cancers
Avoided By System Size
Table 10-16. Total Annual Monetized Health Benefits By System Size
Table 10-17. Upper and Lower Confidence Limits on Risk, Risk Reduction, and Monetary
Benefits Estimates
Table 10-18. Monetized Benefits as a Function of the Value of Statistical Life (VSL)
Table 10-19. Distribution of Radon Mitigation Cost Estimates from Monte Carlo Analysis
Table 10-20. Contributions to Variance in Total Costs by Radon Mitigation Cost Variables
Figure 3-1. General Patterns of Radon Occurrence in Ground Water
Figure 3-2. EPA Map of Radon Zones in Indoor Air
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1. EXECUTIVE SUMMARY
This document constitutes the Regulatory Impact Analysis and Health Risk Reduction
and Cost Analysis (HRRCA) in support of development of a National Primary Drinking Water
Regulation (NPDWR) for radon in drinking water, as required by Section 1412(b)(13) of the
1996 Amendments to the Safe Drinking Water Act (SDWA). The goal of the HRRCA is to
provide a neutral and fact-based analysis of the costs, benefits, and other impacts of controlling
radon levels in drinking water to support future decision making during development of the
radon NPDWR. The document addresses the various requirements for the analysis of benefits,
costs, and other elements specified by Section 1412(b)(13) of the SDWA, as amended.
The HRRCA evaluates optional maximum contaminant levels (MCL) for radon in
drinking water supplies of 100, 300. 500, 700, 1000, 2000, and 4000 PCi/l. The HRRCA also
presents information on the costs and benefits of implementing multimedia mitigation (MMM)
programs. The scenarios evaluated are described in detail in Sections 9 and 10. This executive
summary presents background on the radon in drinking water problem, followed by a summary
of findings.
Background: Radon Health Risks, Occurrence, and Regulatory History
Radon is a naturally occurring volatile gas formed from the normal radioactive decay of
uranium. It is colorless, odorless, tasteless, chemically inert, and radioactive. Uranium is present
in small amounts in most rocks and soil, where it decays to other products including radium, then
to radon. Some of the radon moves through air or water-filled pores in the soil to the soil surface
and enters the air, and can enter buildings through cracks and other holes in the foundation.
Some radon remains below the surface and dissolves in ground water (water that collects and
flows under the ground's surface). Due to their very long half-life (the time required for half of a
given amount of a radionuclide to decay), uranium and radium persist in rock and soil.
Exposure to radon and its progeny is believed to be associated with increased risks of
several kinds of cancer. When radon or its progeny are inhaled,;lung cancer accounts for most of
the total incremental cancer risk. Ingestion of radon in water is: suspected of being associated
with increased risk of tumors of several internal organs, primarily the stomach. As required by
the SDWA, EPA arranged for the National Academy of Sciences (NAS) to assess the health risks
of radon in'drinking water. The NAS released the prepublication draft of the "Report on the
Risks of Radon in Drinking Water,"(NAS Report) in September 1998 (NAS 1998B) and
published the Report in July 1999 (NAS 1999). The analysis in this RIA uses information from
the 1999 NAS Report. The NAS Report represents a comprehensive assessment of scientific
data gathered to date on radon in drinking water. The report, in general, confirms earlier EPA
scientific conclusions and analyses of radon in drinking water (US EPA 1994C).
NAS estimated individual lifetime unit fatal cancer risks associated with exposure to
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radon from domestic water use for ingestion and inhalation pathways (Table ES-1). The results
show that inhalation of radon progeny accounts for most (approximately 88 percent) of the
individual risk associated with domestic water use, with almost all of the remainder (11 percent)
resulting from directly ingesting radon in drinking water. Inhalation of radon progeny is
associated primarily with increased risk of lung cancer, while ingestion exposure is associated
primarily with elevated risk of stomach cancer.
Table ES-1. Estimated Radon Unit Lifetime Fatal Cancer Risks in
Community Water Systems
c n *u Cancer Unit Risk per pCi/1 in
Exposure Pathway v v
II Water
Inhalation of radon
progeny1
Ingestion of radon1
Inhalation of radon gas2
Total
5.9X10-7
7.0X1 0-8
6.3X1 0-9
6.7X1 0'7
Proportion of Total Risk
(Percent)
88
11
1
100
2. Source: Calculated by EPA from radiation dosimetry data and risk coefficients provided by NAS (NAS 1999).
The NAS Report confirmed that indoor air contamination arising from soil gas typically
account for the bulk of total individual risk due to radon exposure. Usually, most radon gas
enters indoor air by diffusion from soils through basement walls or foundation cracks or
openings. Radon in domestic water generally contributes a small proportion of the total radon in
indoor air.
The NAS Report is one of the most important inputs used by EPA in the RIA. EPA has
used the NAS's assessment of the cancer risks from radon in drinking water to estimate both the
health risks posed by existing levels of radon in drinking water and also the cancer deaths
prevented by reducing radon levels.
In updating key analyses and developing the framework for the cost-benefit analysis
presented in the RIA, EPA has consulted with a broad range of stakeholders and technical
experts. Participants in a series of stakeholder meetings held in 1997, 1998, and 1999 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.
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The RIA builds on several technical components, including estimates of radon occurrence
ina water, analytical methods for detecting and measuring radon levels, and treatment
aFes. Extensive analyses of these issues were undertaken by the Agency m the course of
frulemaking efforts for radon and other radionuclides. Using data provided by
hddL and fr°om published literature, the EPA has updated these technical analyses to ake
into account the best currently available information and to respond ta cominen s ^\991
proposed NPDWR for radon. As required by the 1996 Safe Drinking Water Act (SDWA), EPA
has withdrawn the proposed NPDWR for radon (US EPA 1997B) and will propose a new
regulation by August, 1999.
The analysis presented in this RIA uses updated estimates of the number of active: public
drinking water systems obtained from EPA's Safe Drinking Water Information System (SDWIS).
Treatment costs for the removal of radon from drinking water have also been updated. The RIA
follows current EPA policies with regard to the methods and assumptions used in cost and
benefit assessment.
As part of the regulatory development process, EPA has updated and refined its analysis
of radon occurrence patterns in ground water supplies in the United States (US EPA 1998L).
This new analysis incorporates information from the EPA's 1985 NationalAnorganic and
Radionuclides Survey (NIRS) of 1000 community ground water systems throughout the United
States alona with supplemental data provided by the States, water utilities, and academic
research The new study also addressed a number of issues raised by public comments in the
previous occurrence analysis that accompanied the 1991 proposed NPDWR, including
characterization of regional and temporal variability in radon levels, and the impact of sampling
point for monitoring compliance.
In oeneral radon levels in ground water in the United States have been found to be the
highest in New Ensland and the Appalachian uplands of the Middle Atlantic and Southeastern
states There are also isolated areas in the Rocky Mountains, California, Texas, and the upper
Midwest where radon levels in ground water tend to be higher than the United States average.
The lowest ground water radon levels tend to be found in the Mississippi Valley, tower Midwest,
and Plains states. When comparing radon levels in ground water to radon levels m indoor air at
the State level, the distribution of radon concentrations in indoor air do not always mirror
distributions of radon in ground water.
In addition the 1996 Amendments to the SDWA introduce two new elements into the
radon in drinking water rule: (1) an Alternative Maximum Contaminant Level (AMCL) and (2)
multimedia radon mitigation (MMM) programs. The SDWA, as amended provides for
development of an AMCL, which public water systems may comply with if their State has an
EPA approved MMM program to reduce radon in indoor air. The NAS Report estimated that the
AMCL would be about 4,000 PCi/L, based on SDWA requirements. The concept behind the
AMCL and MMM option is to reduce radon health risks by addressing the larger source of
exposure (air levels in homes) compared to drinking water. If a State chooses to employ a MMM
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program to reduce radon risk, it would implement a State program to reduce indoor air levels and
require public water systems to control radon levels in drinking water to the AMCL. If a State
does not choose a MMM program option, a public water system may propose a MMM program
for EPA approval.
Consideration of Regulatory Alternatives
Regulatory Approaches
The RIA evaluates MCL options for radon in drinking water supplies of 100, 300, 500,
700, 1000. 2000, and 4000 pCi/1. It also presents information on the costs and benefits of
implementing multimedia mitigation (MMM) programs. The scenarios evaluated are described
in detail in Sections 9 and 10 of the RIA. Based on the analysis shown in this report, the selected
regulatory alternative discussed below has a significant multimedia mitigation component. A
description of EPA"s process in selecting the MCL and AMCL is shown in Section VII.D of the
preamble.
Selected Regulatory Alternatives
A CWS must monitor for radon in drinking water in accordance with the regulations, as
described in Section VIII of the Preamble, and report their results to the State. If the State
determines that the system is in compliance with the MCL of 300 pCi/1, the CWS does not need
to implement a MMM program (in the absence of a State program), but must continue to monitor
as required.
As discussed in Section VI of the preamble, EPA anticipates that most States will choose
to develop a State-wide MMM program as the most cost-effective approach to radon risk
reduction. In this case, all CWSs within the State may comply with the AMCL of 4000 pCi/1.
Thus, EPA expects the vast majority of CWSs will be subject only to the AMCL. In those
instances where the State does not adopt this approach, the proposed regulation provides the
following requirements:
1. Requirements for Small Systems Serving 10,000 People or Less
The EPA is proposing that small CWSs 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 Diinking 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 SB A Office of Advocacy on the definition as it relates to
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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 RF A for all drinking water regulations and has thus used it for the radon in
drinking water rulemaking. Further information supporting this certification is available m the
public docket for the rule.
EPA's reflation expectation for small CWSs is the MMM and AMCL because this
approach is a much more cost-effective way to reduce radon risk than compliance with the: MCL.
(While EPA believes that the MMM approach is preferable for small systems in a non-MMM
State they may, at their discretion, choose the option of meeting the MCL of 300 pCi/1 instead of
developing a local MMM program). The CWSs will be required to submit MMM program plans
to their State for approval. (See Sections VI. A and F of the preamble for further discussion of
this approach).
SDWA Section 1412(b)(13)(E) directs EPA to take into account the costs and benefits of
programs to reduce radon in indoor air when setting the MCL. In this regard the Agency
expects that implementation of a MMM program and CWS compliance with 4000 pd/1 will
provide neater risk reduction for indoor radon at costs more proportionate to the benefits and
commensurate with the resources of small CWSs. It is EPA's intent to minimize economic
impacts on a significant number of small CWSs, while providing increased public health
protection by emphasizing the more cost-effective multimedia approach for radon risk reduction.
2.
Requirements for Large Systems Serving More Than 10,000 People
The proposal requires large community water systems, those serving populations greater
than 10 000 to comply with the MCL of 300 pCi/1 unless the State develops a State-wide MMM
program, or the CWS develops and implements a MMM program ^^ *" ^"^
requirements, in which case large systems may comply with the AMCL of 4,OOOpCi/l. CWSs
developing their own MMM plans will be required to submit these plans to their State tor
approval.
Baseline Analysis
Data and assumptions used in establishing baselines for the comparison of costs and
benefits are presented in the next section. While the rule as proposed does not require 100/o
compliance with an MCL, an analysis of these full compliance scenarios are required by_the
SDWA, as amended, and were an important feature in the development of the NPDWR tor
radon.
Industry Profile
Radon is found at appreciable levels only in systems that obtain water from groundwater
sources. Thus, only groundwater systems would be affected by the proposed rule. The following
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discussion addresses various characteristics of community groundwater systems that were used in
the assessment of regulatory costs and benefits. Table ES-2 shows the estimated number of
community groundwater systems in the United States. This data originally came from EPA's
Safe Drinking Water Information System (SDWIS) and are summarized in EPA's Drinking
Water Baseline Handbook (US EPA, 1999A). EPA estimates that there were 43,908 community
groundwater systems active in December 1997 when the SDWIS data were evaluated.
Approximately 42,256 or 96.5 percent of the systems serve fewer than 10,000 people, and thus fit
EPA's definition of a "small" system. Privately-owned systems comprise the bulk of the smaller
size categories, whereas most larger systems are publicly owned.
In addition to the number of affected systems, the total number of sources (wells) is an
important determinant of potential radon mitigation costs. Larger systems tend to have larger
numbers of sources than small ones, and it has been assumed in the mitigation cost analysis that
each source out of compliance with the MCL or AMCL would need to install control equipment.
Table ES-3 summarizes the estimated number of wells per groundwater system. Both the
number of wells and the variability in the number of wells increases with the number of people
served. These characteristics of community groundwater sources are included in the mitigation
cost analysis discussed in Section 7.
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Baseline Assumptions
In addition to the characteristics of the groundwater suppliers, other important "baseline"
assumptions were made that affect the estimates of potential costs and benefits of radon
mitigation. Two of the most important assumptions relate to the distribution of radon in
groundwater sources and the technologies that are currently in place at groundwater systems to
control radon and other pollutants.
As noted in Section 3, EPA has recently completed an analysis of the occurrence patterns
of radon in groundwater supplies in the United States (US EPA 1998L). This analysis used the
NIRS and other data sources to estimate national distributions of groundwater radon levels in
community systems of various sizes. The results of that analysis are summarized in Table ES-4.
These distributions are used to calculate baseline individual and population risks, and to predict
the proportions of systems of various sizes that will require radon mitigation.
Table ES-4. Distribution of Radon Levels in U.S. Groundwater Sources
Statistic
Geometric Mean,
pCi/L
Geometric Standard
Deviation, pCi/L
Arithmetic Mean
Population Served
25-100
312
3.04
578
101-500
259
3.31
528
501-3,300
122
3.22
240
3,301-
10,000
124
2.29
175
> 10,000
132
2.31
187
The costs of radon mitigation are affected to some extent by the treatment technologies
that are currently in place to mitigate radon and other pollutants, and by the existence of pre- and
post-treatment technologies that affect the costs of mitigation. EPA has conducted an extensive
analysis of water treatment technologies currently in use by groundwater systems (Table ES-5).
Table ES-5 shows the proportions of ground water systems with specific technologies already in
place, broken down by system size (population served). Many groundwater systems currently
employ disinfection, aeration, or iron/manganese removal technologies. This distribution of pre-
existing technologies serves as the baseline against which incremental water treatment costs are
estimated. For example, costs of disinfection are attributed to the radon rule only for the
estimated proportion of systems that would have to install disinfection as a post-treatment
because they do not already disinfect.
The cost analysis assumes that any system affected by the rule will continue to employ
pre-existing radon treatment technology and pre- and post-treatment technologies in their efforts
to comply with the rule. Where pre- or post-treatment technologies are already in place it is
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assumed that compliance with the radon rule will not require any upgrade or change in the pre- or
post-treatment technologies. Therefore, no incremental cost is attributed to pre- or post-
treatment technologies. This may underestimate costs if pre- or post-treatment technologies need
to be chanaed (e g.. a need for additional chlorination after the installation of packed tower •
aeration). The potential magnitude of this cost underestimation is not known, but is likely to be a
verv small traction of total treatment costs.
Table ES-5. Estimated Proportions of Groundwater Systems With Water Treatment
n-i 1 1 _ • A !_«. A -4-r Swn *Dlr»4*A /T^ <2t*/>ftM t \
Technologies Already in Place (Percent)
System Size (Population Served)
Water Treatment
Technologies in Place
Fe/Mn Removal &
Aeration &
Disinfection
Fe/Mn Removal &
Aeration
Fe/Mn Removal &
Disinfection
Fe/Mn Removal
Aeration &
Disinfection Only
Aeration Only
Disinfection Only
0.4
0.0
2.1
1.9
0.9
0.8
49.6
0.2
0.1
5.1
1.5
5.2
1.0
68.2
1.2
0.2
8.3
1.5
9.8
1.8
65.0
65.0
56.3
66.0
' . Source: EPA analysis of data Fr m the Community Water System Survey (CWSS). .997. and Safe Drinking Water Information
0.6
0.1
3.0
1.0
13.7
2.9
2.9
0.4
7.8
1.1
20.9
2.9
2.2
0.1
7.4
0.4
19.7
1.0
3.1
0.4
9.7
1.1
18.6
2.1
2.0
0.1
6.8
0.2
19.9
0.6
68.3
The treatment baseline assumptions shown in Table ES-5 were used in the initial analysis
for the development of the NPDWR for radon. These assumptions were used to establish the
costs of 100% compliance with an MCL. Another analysis, w;hich portrays the costs of the rule
as recommended in this proposed rulemaking, is provided in the results section of the Executive
Summary and also in Section 9 of this RIA.
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Benefits Analysis
Quantifiable and Non-Quantifiable Health Benefits
The quantifiable 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. Table ES-6 shows the health risk reductions (number of fatal and non-fatal cancers
avoided) and the residual health risk (number of remaining cancer cases) at various radon in
water levels.
Table ES-6. Residual Cancer Risk and Risk Reduction from
Radon
Level
(pCi/1 in
water)
(Baseline)
4,000:
2,000
1,000
700
500
300
100
Residual Fatal
Cancer Risk
(Cases per
Year)
168
165
160
150
141
130
106
46.8
Residual Non-
Fatal Cancer Risk
(Cases per Year)
9.7
9.5
9.4
8.8
8.3
7.6
6.1
2.8
Risk Reduction
(Fatal Cancers
Avoided p;.- Year)1
0
2.9
7.3
17.8
26.1
37.6
62.0
120
Risk Reduction
(Non-Fatal Cancers
Avoided per Year)1
0
0.2
0.4
1.1
1.5
2.2
3.6
7.0
I. Risk reductions and residual risk estimates are slightly inconsistent due to rounding.
2.4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA provisions of Section I412(b)(13).
Since preparing the prepublication edition of the NAS Report, the NAS has reviewed and
slightly revised their unit risk estimates. EPA uses these updated unit risk estimates in
calculating the baseline risks, health risk reductions, and residual risks. Under baseline
assumptions (no control of radon exposure), approximately 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/1, approximately 2.9 fatal cancers and 0.2 non-fatal cancers per year are prevented. At'300
pC5/l, approximately 62.0 fatal cancers and 3.6 non-fatal cancers are prevented each year.
The Agency has developed monetized estimates of the health benefits associated with the
risk reductions from radon exposures. The SDWA, as amended, requires that a cost-benefit
September, 1999 - Draft Document
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analysis be conducted for each NPDWR, and places a high priority on better analysis to support
mlenSina The Agency is interested in refining its approach to both the cost and benefit
"and in partlculi recognizes that there are different approaches to ™°«^^*
benefits. In the past, the Agency has presented benefits as cost per life saved, as in Table ES-7.
The costs of reducins radon to various levels, assuming 100% compliance with an MCL
of 300 PCi/l a e summarized below in Table ES-7. The table shows that, as expected, aggregate
radon motion costs increase with decreasing radon levels. For CWSs, the costs per system do
not vaw substantially across the different radon levels evaluated. This is because the menu of
SiStol^olois for systems with various influent radon levels remams relatively constant
and are not sensitive to percent removal.
Table ES-7. Estimated Annualized National Costs of Reducing Radon Exposures
Assuming 100% Compliance with an MCUSMillion, 1997)
Cost Per Fatal Cancer
Total Annualized National
Central Tendency
Radon Level
Case Avoided
(pCi/1) Estimate of Annualized
. 4000 p i/l is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section 1412(b)(13)
' Costs include treatment, monitoring, and O&M costs only.
, reporting,^ state costs for administration of water
An alternative approach presented here for consideration as one measure of potential
benefits is the monetary value of a statistical life (VSL) applied to each fatal cancer avoided.
S^ce his rprTh Relatively new to the development of NPDWRs, EPA is interested m
^mments on these alternative approaches to valuing benefits, and will have to welgh the value
of these approaches for future use.
Estimating the VSL involves inferring individuals' implicit tradeoffs between small
changes in mortality risk and monetary compensation. In the HRRCA, a central tendency
estSe of $5.8 minion (1997$) is used in the monetary benefits calculations. This figure was
determined from VSL estimates from 26 studies reviewed in EPA's recent draft guidance on
benefits assessment (US EPA 1999B), which is currently under review by the Agency s Science
Advisory Board (SAB) and the Office of Management and Budget (OMB).
September, 1999 - Draft Document
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It is important to recognize the limitations of existing VSL estimates and to consider
whether factors such as differences in the demographic characteristics of the populations and
differences in the nature of the risks being valued have a significant impact on the value of
mortality risk reduction benefits. Also, medical care or lost-time costs are not separately
included in the benefits estimate for fatal cancers, since it is assumed that these costs are captured
in the VSL for fatal cancers.
For non-fatal cancers, willingness to pay (WTP) data to avoid chronic bronchitis is used
as a surrogate to estimate the WTP to avoid non-fatal lung and stomach cancers. The use of such
WTP estimates is supported in the SDWA, as amended, at Section 1412(b)(3)(C)(iii)- "The
Administrator may identify valid approaches for the measurement and valuation of benefits under
this subparagraph, including approaches to identify consumer willingness to pay for reductions in
health risks from drinking water contaminants."
A WTP central tendency estimate of $536,000 per case is used to monetize the benefits of
avoiding non-fatal cancers (Viscusi et al. 1991). The combined fatal and non-fatal health
benefits are summarized in Table ES-8. The annual health benefits range from $170 million for
a radon level of 4000 pCi/1 to $702 million at 100 pCi/1.
Table ES-8. Estimated Monetized Health Benefits from Reducing
Radon Level
(pCi/1)
4,0002
2,000
1,000
700
500
300
100
Monetized Health Benefits,
Central Tendency
(Annualized, $Millions, 1997)'
17.0
42.7
103
152
219
362
VSL of rmT ^ a±°n'fatal CanCCrS- estimated usin§ centl'al tendency
VSL of S5.8 million (1997S), and a WTP to avoid non-fatal cancers of S536 000 (1997$)
'y1 !S equivalent to the AMCL estimated by «« NAS based on SDWA provisions of Section
Non-quantifiable benefits might also be associated with reductions in radon exposures
EPA has Identified several potential non-quantifiable benefits associated with regulating radon in
September, 1999 - Draft Document
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drinkino water These benefits may include any customer peace of mind from knowing drinking
t?erh°as been treated for radon. In addition, if chlorination is added to the process of treating
Tado vS aeration, arsenic pre-oxidation will be facilitated. Neither chlonna.on n^r aeraUon
will remove arsenic, but chlorination will facilitate conversion of Arsenic (III) to Arsenic (V).
A^enMV) is aTes soluble form that can be better removed by arsenic removal technologies. In
fenTof reducing radon exposures in indoor air, it has also been suggested that the provision of
Snation to households on the risks of radon in indoor air and the availability of options to
edu™ exposure may be a non-quantifiable benefit that can be attnbuted to some components of
at^TpWam. Providing such information might allow households to make more informed
ch^es about the need for risk reduction given their specific circumstances and concerns than
they would have in absence of an MMM program. In the case of the proposed radon rule, it is
rS Hkely that accounting for these non-quantifiable benefits would significantly alter the overall
assessment.
Cost Analysis
Total National Costs of Compliance With MCL Options
Table ES-9 summarizes the estimates of total national costs of compliance with the range
of potential MCLs considered. The table is divided into two major groupings; the first grouping
displays the estimated costs to systems and the second grouping displays the estimated costs to
States.
State costs, presented in Table ES-9, were developed as part of the analyses to comply
with the Unfunded Mandates Reform Act (UMRA) and the Paperwork Reduction Ac (PRA).
Additional information on State costs is provided in Section 8 and also in the preamble to the
proposed radon rule.
September, 1999 - Draft Document
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Table ES-9. Summary of Estimated Costs Under the Proposed Radon Rule Assuming
100% Compliance with an MCL of 300 pCi/1 (S Millions. 1997V
3 Percent Cost
of Capital
7 Percent Cost
of Capital
10 Percent
Cost of
ital
Costs to Water Systems
Total Capital Costs (20 Years,
undiscounted)
Annual Costs
Annualized Capital
Annual O&M
Total Annual Treatment
Monitoring Costs
Recordkeeping and Reporting
Costs2
Total Annual Costs to Water
Systems3
Administration of Water
Programs
Annual State Costs
Total Annual Costs of
Compliance4
1. Assumes no MMM program implementation costs.
2. Figure represents average annual burden over 20 years.
3. Costs include treatment, monitoring. O&M, recordkeeping. and reporting costs to water systems.
4. Totals have been rounded. Costs include treatment, monitoring, O&M, recordkeepina. reporting, and state costs for
administration of water programs.
Quantifiable and Non-Quantifiable Costs
The capital and operating and maintenance (O&M) costs of mitigating radon in
Community Water Systems (CWSs) were estimated for each of the radon levels evaluated. The
costs of reducing radon in ground water to specific target levels were calculated using the cost
curves discussed in Section 7.5 and the matrix of treatment options presented in Section 7.6 of
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this analvsis. For each radon level and system size stratum, the number of systems that need to
reduce radon levels by up to 50 percent, 80 percent and 99 percent were calculated. Then the
cost curves for the distributions of technologies dictated by the treatment matrix were applied to
the appropriate proportions of the systems. Capital and O&M costs were then calculated for each
system based on typical estimated design and average flow rates. These flow rates were
SuLd on spreadsheets using equations from EPA's Baseline Handbook (US EPA 1999A).
The equations and parameter values relating system size to flow rates are presented in Appendix
C The technoloaies addressed in the cost estimation included a number of aeration and granular
activated carbon^GAC) technologies described in Section 7.2, ;as well as storage, regionalization,
and disinfection as a post-treatment. To estimate costs, water systems were assumed (with a few
exceptions to simulate site-specific problems) to select the technology that could reduce radon to
the selected target level at the lowest cost. CWSs were also assumed to treat separately at every
source from which water was obtained and delivered into the distribution system.
EPA has attempted to note potential non-quantifiable benefits when the Agency believes
they mioht occur, as in the case of peace of mind benefits from radon reduction. The Agency
recognises that there may also be non-quantifiable disbenefits,such as anxiety on the part of
those near aeration plants or those who find out that their radon levels are high. It is not possible
to determine whether the net results of such psychological effects would be positive or negative.
The inclusion of non-quantifiable benefits and costs in this analysis are not likely to alter the
overall results of the benefit-cost analysis for the proposed radpn rule.
Weighing the Benefits and Costs
Incremental Costs and Benefits of Radon Removal
Table ES-10 summarizes the central tendency estimates of the incremental costs and
benefits of radon exposure reduction assuming 100% compliance with an MCL Both the annual
incremental costs and benefits increase as the radon level decreases from 4000 pCi/1 downi to,100
PCi/l. Incremental costs and benefits are within 10 percent of each other at radon levels of 2000,
1000, and 500 pCi/1.
September, 1999 - Draft Document
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Table ES-10. Estimates of the Annual Incremental Risk Reduction, Costs, and Benefits of
Reducing Radon in Drinking Water Assuming 100% Compliance
with an MCL of 300 pCi/1 (SMillions, 1997)
Incremental Risk Reduction, Fatal
Cancers Avoided Per Year
Incremental Risk Reduction, Non-
Fatal Cancers Avoided Per Year
Annual Incremental Monetized
Benefits, $ Millions Per Year
Annual Incremental Radon
Mitigation Costs, $ Millions Per
Year**
Radon Level, pCi/I
4000*
2.9
0.2
17.0
34.5
2.000
4.4
0.3
25.7
26.6
1,000
10.5
0.6
61.0
60.8
700
8.4
0.4
48.7
54.9
500
11.5
0.8
67.1
72.0
300
24.4
1.3
142
150.3
100
58.4
3.5
341
408.5
*4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section I4l2(b)(13).
"Costs include treatment, monitoring, and O&M co'sts only.
September, 1999 - Draft Document
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Impacts on Households
The cost impact of reducing radon in drinking water at the household level was also
assessed. As expected, costs per household increase as system size decreases as shown in Table
ES 11
Table ES-11 Annual Costs per Household for Community Water Systems to Treat to
Various Radon Levels*(S, 1997^
'-! '"' "
Households Served by PRIVATE System
Households Served by PUBLIC Systems
' Above Radon level
"Reflects total household costs for systems to treat down to these radon levels. Because EPA expects that most systems will
IN.CI1CUIS LUlttI nuuoviiwuj wvj^^-. .«• -.,
complv with the AMCL/MMM. most systems will not incur these household costs.
mn v with trie AlvlVwL,/vnvuvi. IIK-IOI.->j>ji.^"i-> •••••••— . in»u\/i->\
4000 pCi/1 is equivalent to the AMCL estimated by the HAS based on SDWA requ.rements of Sectton 1412(b)(l,).
Costs to households are higher for households served by smaller systems than larger
systems for two reasons. First, smaller systems serve far fewer households than larger systems
Id consequently, each household must bear a greater percentage share of the capital and O&M
cost's. Second, smaller systems tend to have higher influent radon concentrations that, on a per-
capita or per-household basis, require more expensive treatment methods e.g one tha has an 85
percent removal efficiency rather than 50 percent) to achieve the applicable radon level.
To further evaluate the impacts of these household costs, the costs per household were
compared to median household income data for each system-size category. The results of this
calculation, presented in Table ES-12 for public and private systems, indicate a household s
likely share of average incremental costs in terms of the median income. Actual costs for
individual households will reflect higher or lower income shares depending on whether they are
Lbove or below the median household income (approximately $30,000 per year) and whetfier the
water system incurs above average or below average costs for installing treatment. For all system
sizes but very very small private systems, average household costs as a percentage of median
September, 1999 - Draft Document
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household income are less than one percent for households served by either public or private
systems. Average impacts exceed one percent only for households served by very very small
private systems, which are expected to face average impacts of 1.12 percent at the 4,000 pCi/1
level and 1.35 percent at the 300 pCi/1 level and for households served by very very small public
systems at the 300 pCi/1 level, whose average costs barely exceed one percent. Similar to the
average cost per household results on which they are based, average household impacts exhibit
little variability across radon levels.
Table ES-12 Per Household Impact by Community Groundwater Systems as a Percentage of
Median Household Income (Percent)
Radon
Level,
pCi/1
4000'
2000
1000
700
500
300
100
Average Impact to Households Served
by Public Systems Exceeding Radon
Levels
vvs
(25-
100)
0.86
0.92
0.96
0.98
1.00
1.05
1.17
VVS
(101-
500)
0.30
0.36
0.38
0.38
0.39
0.40
0.44
VS
0.13
0.12
0.13
0.13
0.13
0.14
0.15
S
0.06
0.05
0.05
0.06
0.06
0.06
0.07
M
0.03
0.02
0.02
0.03
0.03
0.03
0.05
L
0.02
0.01
0.0 1
0.02
0.02
0.02
0.03
Average Impact to Households Served by
Private Systems Exceeding Radon Levels
VVS
(25-
100)
1.12
1.19
1.24
1.27
1.30
1.35
1.51
VVS
(101-
500)
0.35
0.42
0.44
0.45
0.45
0.47
0.51
VS
0.16
0.16
0.16
0.17
0.17
0.18
0.19
S
0.07
0.09
0.09
0.09
0.09
0.10
0.12
M
0.04
0.02
0.03
0.03
0.03
0.04
0.05
L
0.02
0.01
0.01
0.01
0.01
0.02
0.02
1. 4000 pCi/I is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section 1412(b)( 13).
Summary of Annual Costs and Benefits
Table ES-13 reveals that at a radon level of 4000pCi/l (equivalent to the AMCL estimated
in the NAS Report), annual costs of 100% compliance with the MCL are approximately twice the
annual monetized benefits. For radon levels of 1000pCi/l to 300 pCi/1, the central tendency
estimates of annual costs are above the central tendency estimates of the monetized benefits.
September, 1999 — Draft Document
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Table ES-13 Estimated National Annual Water Mitigation Costs and Benefits of Reducing
Radon Exposures Assuming 100% Compliance with an MCL - Central Tendency Estimate
(SMillions, 1997)'
Total Annual Costs
of Compliance"
Notes- 1 Benefits are calculated for stomach and lung cancer assuming that risk reduction begins immediately. Estimates
assume a S5 8 million value of a statistical life and willingness to pay of S536.000 for non-fatal cancers.
Tcosts are annualized over twenty years using a discount rate of seven percent. Costs include treatment, monitoring, and O&M
frosts include treatment, monitoring, O&M, recordkeeping. reporting, and state costs for administration of water programs.
4! 4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements ot Section 1412(b)(13).
Because the costs of compliance with the MCL for small systems outweigh the benefits at
each radon level, the MMM option was recommended for small systems to alleviate some of the
financial burden to small systems and the households they serve and to realize equivalent or
oreater benefits at much lower costs. The results of benefit-cost analyses for MMM
implementation scenarios are shown at the end of this section and also in Section 9 of this RIA.
Benefits from the Reduction of Co-Occurring Contaminants
The occurrence patterns of other industrial pollutants are difficult to clearly define at the
national level relative to a naturally occurring contaminant such as radon. Similarly, the
Agency's re-evaluation of radon occurrence has revealed that the geographic patterns of radon
occurrence are not significantly correlated with other naturally occurring inorganic contaminants
that may pose health risks. Thus, it is not likely that a clear relationship exists between the need
to install radon treatment technologies and treatments to remove other contaminants. On the
other hand, technologies used to reduce radon levels in drinking water have the potential to
reduce concentrations of other pollutants as well. Aeration technologies will also remove
volatile organic contaminants from contaminated ground water. Similarly, granular activated
carbon (GAC) treatment for radon removal effectively reduces the concentrations of organic
(both volatile and nonvolatile) chemicals and some inorganic contaminants. Aeration also tends
to oxidize dissolved arsenic (a known carcinogen) to a less soluble form that is more easily
removed from water. The frequency and extent to which radon treatment would also reduce risks
from other contaminants has not been quantitatively evaluated.
September, 1999 - Draft Document
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Impacts on Sensitive Subpopulations
The SDWA, as amended, includes specific provisions in Section 1412(b)(3)(C)(i)(V) to
assess the effects of the contaminant on the general population and on groups within the general
population such as children, pregnant women, the elderly, individuals with a history of serious
illness, or other subpopulations that are identified as likely to be at greater risk of adverse health
effects due to exposure to contaminants in drinking water than the general population. The NAS
Report concluded that there is insufficient scientific information to permit separate cancer risk
estimates for potential subpopulations such as pregnant women, the elderly, children, and
seriously ill persons. The NAS Report did note, however, that according to the NAS model for
the cancer risk from ingested radon, which accounts for 11% of the total fatal cancer risk from
radon in drinking water, approximately 30% of the fatal lifetime cancer risk is attributed to
exposure between ages 0 to 10.
The NAS Report identified smokers as the only group that is more susceptible to
inhalation exposure to radon progeny (NAS 1998A, 1999) than the general population.
Inhalation of cigarette smoke and radon progeny result in a greater increased risk than if the two
exposures act independently to induce lung cancer. NAS estimates that "ever smokers" (more
than 100 cigarettes over a lifetime) may be more than five times as sensitive to radon progeny as
"never smokers" (less than 100 cigarettes over a lifetime). Using current smoking prevalence
data, EPA's preliminary estimate for the purposes of the HRRCA is that approximately 85
percent of the cases of radon-induced cancer will occur among current and former smokers. This
population of current and former smokers, which consists of 58 percent of the male and 42
percent of the female population (US EPA 1999D), will also experience the bulk of the risk
reduction from radon exposure reduction in drinking water supplies.
Risk Increases from Other Contaminants Associated With Radon Exposure Reduction
As discussed in Section 7.2, the need to install radon treatment technologies may require
some systems that currently do not disinfect to do so. Case studies (US EPA 1998D) of twenty-
nine small to medium water systems that installed treatment (24 aeration, 5 GAC) to remove
radon from drinking water revealed only two systems that reported adding disinfection (both
aeration) with radon treatment (the other systems either had disinfection already in place or did
not add it). In practice, the tendency to add other disinfection with radon treatment may be much
more significant than these case studies indicate. EPA also realizes that the addition of
chlorination for disinfection may result in risk-risk tradeoffs, since, for example, the disinfection
technology reduces potential for infectious disease risk, but at the same time can result in
increased exposures to disinfection by-products (DBPs). This risk-risk trade-off is addressed by
the recently promulgated Disinfectants and Disinfection By-Products NPDWR (US EPA 19981).
This rule identified MCLs for the major DBPs, with which all CWSs and NTNCWSs must
comply. These MCLs set a risk ceiling from DBPs that water systems adding disinfection in
conjunction with treatment for radon removal could face. The formation of DBPs correlates with
September, 1999 — Draft Document
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the concentration of organic precursor contaminants, which tend to be much lower in ground
water than in surface water. In support of this statement, the American Water Works
Association's WATERS!ATS survey reports that more than 50% of the ground water systems
surveyed have average total organic carbon (TOC) raw water levels less than 1 mg/L and more
than 80% had TOC levels less than 3 mg/L. On the other hand. WATERSTATS reports that less
than 6% of surface water systems surveyed had raw water TOC levels less than 1 mg/L and more
than 50% had raw water TOC levels greater than 3 mg/L. In fact, this survey reports that more
than 85% of surface water systems had finished water TOC levels greater than 1 mg/L.
The NAS Report addressed several important potential risk-risk tradeoffs associated with
reducing radon levels in drinking water, including the trade-off between risk reduction from
radon treatment that includes post-disinfection with the increased potential for DBF formation
(NAS 1999). The report concluded that, based upon median arid average total trihalomethane
(THM) levels taken from a 1981 survey, ground water systems would face an incremental
individual lifetime cancer risk due to chlorination byproducts of 5x10°". It should be emphasized
that this risk is based on average and median Trihalomethane (THM) occurrence information that
does not segregate systems that disinfect from those that do. It should also be noted that this
survey pre-dates the promulgation of the Stage I Disinfection Byproducts Rule by almost twenty
years. Further, the NAS Report points out that this average DBF risk is smaller than the average
individual lifetime fatal cancer risk associated with baseline radon exposures from ground water
(untreated for radon), which is estimated at 1.2 x 10'4 using a mean radon concentration of 213
pCi/l.
While this risk comparison is instructive, a more meaningful relationship for the proposed
radon rule would be to compare the trade-off between radon risk reduction from radon treatment
and introduced DBF risk from disinfection added along with radon treatment. EPA emphasizes
that this risk trade-off is only of concern to the small minority (<1%) of small ground water
systems with radon levels above the AMCL of 4000 pCi/L and to the small minority of large
ground water systems that are not already disinfecting. Presently, approximately half of all small
community ground water systems already have disinfection in place, as shown in Table ES-5.
The proportion of systems having disinfection in place increases as the system's size increases;
>95% of large ground water systems currently disinfect. In terms ofthe populations served, 83%
of persons served by small community ground water systems (those serving 10,000 persons or
fewer) already receive disinfected drinking water and 95% of persons served by large ground
water systems already receive disinfected drinking water. As shown in Tables ES-14 and ES-lD,
even for those ground water systems adding both radon treatment and disinfection, this risk-risk
trade-off tends^o be very favorable, since the risk reduction from radon removal greatly
outweighs the added risk from DBF formation.
An estimate of the risk reduction due to treatment of radon in water for various removal
percentages and finished water concentrations is provided in Table ES-14. These risk reductions
are much greater than NAS's estimate of the average lifetime risk from DBF exposure for ground
water systems, by factors ranging from 3.5 for low radon removal efficiencies (50%) to more
September, 1999 - Draft Document
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than 130 for higher radon removal efficiencies (>95%).
Table ES-14. Radon Risk Reductions Resulting from Water Treatment
Radon Influent (Raw Water) Level,
pCi/L
500
750
1000
2500
4000
10000
Required Removal
Efficiency
52%
68%
76%
90%
94%
98%
Reduced Lifetime Risk Resulting
from Water Treatment for Radon
in Drinking Water'
1.7 x 10-4
3.4 x lO"4
5.1 x 10-4
1.5 x ID'3
2.5 x 10'3
6.5 x 10'3
Notes: 1 ) Assumes that water is treated to 80% of the radon MCL.
Table ES-15 demonstrates the risk-risk trade-off between the risk reduction from radon
removal and the risks introduced from total trihalomethanes (TTHM) for two scenarios: 1) the
resulting TTHM level is 0.008 mg/L (10% of the TTHM MCL) and 2) the resulting TTHM level
is 0.080 mg/L (the TTHM MCL). The table demonstrates that the risk-risk trade-off is
favorable for treatment with disinfection, even for situations where radon removal efficiencies
are low (50%) and TTHM levels are present at the MCL. While accounting quantitatively for the
increased risk from DBF exposure for systems adding chlorination in conjunction with treatment
for radon may somewhat decrease the monetized benefits estimates, disinfection may also
produce additional benefits from the reduced risks of microbial contamination.
September, 1999 — Draft Document
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Table ES-15. Radon Risk Reduction from Treatment Compared to DBF Risks
Radon Influent
(Raw Water) Level,
pCi/L
500
750
1000
2500
4000
10000
Estimated Risk Ratios:
(Lifetime Risk Reduction from Radon Removal1 / Lifetime Average Risk from
TTHMs in Chlorinated Groundwater)
(NAS);
4
7
10
30
50
130
Notes:
1) From Table ES- 14.
2) From Appendix D in: National Research Coun
Academy Press, Washington, DC. 1999. DBF
Stage I DBF NPDWR.
3) US EPA. Regulatory Impact Analysis for the S
The Cadmus Group. November 12. 1998. Ana
the Integrated Risk Information System (IRIS)
comprised by 70% chloroform, 21% bromodicl
4) US EPA. Regulatory Impact Analysis for the S
the 95% upper confidence interval value from t
unit risk for dibromochloromethane (2.4 \ 10"*
TTHMs Present at 10% of
TTHM MCL (0.080 mg/L)3
30
60
90
300
500 ;
1200
TTHMs Present at MCL
3
6
9
30
50
120
cil. Risk Assessment of Radon in Drinking Water. National
concentrations are from a 1 98 1 study and therefore pre-date the
tage I Disinfectants/Disinfection Byproducts Rule. Prepared by
ilysis is based on the 95% upper confidence interval value from
lifetime unit risks for each THM. TTHM is assumed to
iloromethane, 8% dibromochloromethane. and 1% bromoform.
tage 1 Disinfectants/Disinfection Byproducts Rule. Based on
he Integrated Risk Information System (IRIS) for the lifetime
risk of cancer case over 70 years of exposure).
Other Factors: Uncertainty in Risk, Benefit, and Cost Estimates
Estimates of health benefits from radon reduction are uncertain. EPA is including an
uncertainty analysis of radon in drinking water risks with the proposed rule. This uncertainty
analysis is discussed in Section 10.8 of this analysis. Monetary benefit estimates are also
affected by the VSL estimate that is used for fatal cancers. The WTP valuation for non-fatal
cancers has less impact on benefit estimates because it contributes less than 1 percent to the total
benefits estimates, due to the fact that there are few non-fatal cancers relative to fatal cancers and
the estimated value of a non-fatal cancer case is lower relative to the value of a fatal cancer case.
September, 1999 — Draft Document
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Costs and Benefits of Multimedia Mitigation Program Implementation Scenarios
In addition to evaluating the costs and benefits across a range of radon levels, EPA has
evaluated five scenarios that reduce radon exposure through the use of MMM programs. The
implementation assumptions for each scenario are described in the next section. These five
scenarios are described in detail in Section 9 of this analysis. For the MMM implementation
analysis, systems were assumed to mitigate water to the 4,000 pCi/1 Alternative Maximum
Contaminant Level (AMCL), if necessary, and that an equivalent or greater risk reduction
between the AMCL and the radon level under evaluation would be achieved through a MMM
program. Therefore, the actual number of cancer cases avoided is the same for the MMM
implementation scenarios as for the water mitigation only scenario of 300 pCi/1. A complete
discussion on why MMM is expected to achieve equal or greater risk reduction is shown in
Section VLB of the preamble for the proposed radon rule.
Implementation Scenarios
EPA evaluated the annual cost of five MMM implementation scenarios that span the
range of participation in MMM programs that might occur when a radon NPDWR is
implemented. Each scenario assumes a different proportion of States will comply with the
AMCL and implement MMM programs. It has been assumed that "50 percent of States" implies
50 percent of systems in the U.S; "60 percent of States" implies 60 percent of systems, and so on.
Scenario A: 50 percent of States implement MMM programs.
Scenario B: 60 percent of States implement MMM programs.
Scenario C: 70 percent of States implement MMM programs.
Scenario D: 80 percent of States implement MMM programs.
Scenario E: 95 percent of States implement MMM programs.
States that do not implement MMM programs instead must review and approve any
system-level MMM programs prepared by community water systems. In these States, regardless
of scenario, 90 percent of systems are assumed to comply with the AMCL and to implement a
system-level MMM program and 10 percent are assumed to comply with the MCL.
Costs and Benefits of MMM Implementation Scenarios
Table ES-16 shows the total annual system-level and State-level costs at 300 pCi/1 for
each scenario. Additional MMM scenario cost and benefit tables for MCL levels of 100, 500,
700, 1000, 2000, and 4000 pCi/1 are shown in Appendix E. System, State, and MMM mitigation
costs decrease from $121.1 million to $60.4 million as the percentage of States implementing
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MMM programs increases from 50 to 95 percent. System-level costs decrease from $104 million
to $47.4 million as the percentage of States implementing MMM programs increases from 50 to
95 percent.
A detailed cost-benefit analysis in support of the Radon Rule is shown in Sections 9 and
10 of this RIA. This proposed rule is expected to have a total annualized cost (at 300 pCi/1) of
approximately $121.1 million with a range of potential impacts from $60.4 million 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
conservatively assumes 50% of States implement MMM programs with the remaining 50% of
States implementing system-level MMM programs or complying with the MCL. Under Scenario
E, total costs are approximately $60.4 million. A detailed description of these scenarios is shown
in Section 9).
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Table ES-16 (A) Annual System-Level and State-Level Costs Associated with
the Multimedia Mitigation and AMCL Option (SMillions/Year) (MCL = 300 pCi/L)
System Size
25-100
101-500
501-3300
3301-10.000
10.001 -100.000
> 1 00.000
Total CWS Water
Mitigation Costs
System Size
25-100
101-500
501-3300
3301-10.000
10.001 -100.000
> 100.000
Total CWS
Administrative
Costs
Total CWS
Water Mitigation
and
Administrative
Costs
Scenario A
45% Implement
System-Level
MMM Program;
5% Mitigate
Water to 300
piC/L MCL; 95%
Mitigate Water to
4000 piC/L
AMCL
Scenario B
36% Implement
System-Level
MMM Program;
4% Mitigate
Water to 300
piC/L MCL; 96%
Mitigate Water to
4000 piC/L
AMCL
Scenario C
27% Implement
System-Level
MMM Program;
3% Mitigate
Water to 300
piC/L MCL; 97%
Mitigate Water to
4000 piC/L
AMCL
Scenario D
18% Implement
System-Level
MMM Program;
2% Mitigate
Water to 300
piC/L MCL; 98%
Mitigate Water to
4000 piC/L
AMCL
Scenario E
5% Implement
System-Level
MMM Program;
.5% Mitigate
Water to 300
piC/L MCL;
99.5% Mitigate
Water to 4000
piC/LAMCL
System Costs for Water Mitigation (S millions/year)
10.2
17.6
9.9
5.5
7.5
2.0
52.7
9.7
16.9
9.2
5.0
6.6
1.7
49.1
9.3
16.3
8.5
4.5
5.6
1.4
45.4
8.8
15.6
7.7
3.9
4.6
1.1
41.8
8.1
14.6
6.7
3.1
3.2
0.7
36.3
Water System Administration Costs (S millions/year)
Scenario A
17.0
17.4
12.0
3.0
1.7
0.1
51.2
104.0
Scenario B
14.0
14.3
9.9
2.5
1.4
O.I
42.1
91.2
Scenario C
11.0
11.3
7.8
1.9
1.1
0.1
33.1
78.5
Scenario D
8.0
8.2
5.7
1.4
0.8
0.0
24.1
65.9
Scenario E
3.7
3.8
2.6
0.6
0.4
0.0
11.1
47.4
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Table ES-16 (B) State MMM Administrative Costs (S millions/year)
Scenario A
50% of States
Implement State-
wide MMM
Program; 45% of
CWS Implement
System-Level
MMM Program
Scenario B
60% of States
Implement State-
wide MMM
Program; 35% of
CWS Implement
System-Level
MMM Program
Scenario C
70% of States
Implement State-
wide MMM
Program; 25% of
CWS Implement
System-Level
MMM Program
Scenario D
80% of States
Implement State-
wide MMM
Program; 15% of
CWS Implement
System-Level
MMM Program
Scenario E
95% of States
Implement State-
wide MMM
Program; 5% of
CWS Implement
System-Level
MMM Program
State costs associated with State-wide MMM program administration, reviewing system-level
MMM proarams, and reviewing system-level water mitigation requirements are not distributable
across different system sizes.
State
Administration
Costs for Water
Mitigation
State
Administration
Costs for State-
Level MMM
Mitigation
State
Administration
Costs for System-
Level MMM
Mitigation
Total State
Administration
Costs
2.5
2.9
7.8
13.2
2.5
3.5
6.1
12.1
2.5
4.1
4.4 ;
10.9
2.5
4.7
2.6
9.8
2.5
5.6
0.9
8.9
Table ES-16 (C) MMM Testing and Mitigation Costs (Smillions/year)
CWS MMM
Costs
State MMM
Costs
Total MMM
Costs
TOTAL COSTS
(From Tables
XIII.18A, B,
andC)
Scenario A
1.9
2.1
3.91
121.1
Scenario B
1.5
2.5
3.95
107.3
Scenario C
1.1
2.9
3.99
93.4
Scenario D
0.7
3.3
4.03
79.7
Scenario E
0.2
3.9
4:12
60.4
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Table ES-17 presents the ratios of benefits to costs of MMM programs for each scenario,
by system size. Benefit-cost ratios are less than one for the smallest system size category
(systems serving less than 500 people), but greater than one for larger systems under all five
scenarios. For the large systems, benefit-cost ratios range from 2.6 for systems serving 501-
3,300 people under Scenario A to approximately 41.4 for systems serving 10,000 to 100,000
people under Scenario E. Overall benefit-cost ratios are over one for all five scenarios. This
pattern is seen primarily because a larger proportion of smaller systems have influent radon
levels exceeding 4000 pCi/1. A larger proportion of small systems versus large systems
therefore, incur water mitigation costs to comply with the AMCL.
Table ES-17. Ratio of Benefits and Costs by System Size
for Each Scenario (MCL = 300 pCi/1)
System Size
25-100
101-500
501-3.300
5,301-10,000
10,001-
100.000
> 100,000
OVERALL
1 Benefits,
1 $M
3.5
16.9
58.0
59.2
147.3
76.7
361.6
Scenario A
0.13
0.48
2.59
6.87
15.82
37.16
2.98
Scenario B
0.14
0.53
2.98
7.85
18.35
43.70
3.37
Scenario C
0.17
0.61
3.51
9.16
21.84
53.04
3.87
Scenario D
0.21
0.70
4.27
11.0
26.96
67.44
4.54
Scenario E
0.30
0.92
6.23
15.61
41.43
113.68
5.99
Table ES-18 shows the net benefits (benefits minus costs) of the various MMM
implementation scenarios. Only the ratios in the bottom row of the table include costs to the
States. The balance of the numbers presented here represent local benefits and costs only and as
such, somewhat overstate the net benefits of the scenarios. As would be expected from the
benefit-cost ratios shown in Table ES-17, all systems serving more than 500 people realize
positive net benefits under all five scenarios. By far the largest proportion of net benefits is
realized by systems serving 10,000 to 100,000 people.
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Size for Each Scenario
18. Net Benefits by System
2. INTRODUCTION
2.1 Background
This Regulatory Impact Analysis (RIA) and Health Risk Reduction and Cost Analysis
(HRRCA) illustrates the Environmental Protection Agency's (EPA) analysis of potential costs
and benefits of different target levels and MMM implementation scenarios for radon in drinking
water Two cost analyses are provided in this RIA. The first analysis was done as part of an
initial analysis as required by SDWA, as amended, and the second analysis shows estimated
costs for the rule as proposed. For the initial analysis, assuming 100% compliance with optional
MCLs the HRRCA builds on several technical components, including estimates of radon
occurrence in drinking water supplies, analytical methods for detecting and measuring radon
levels and treatment technologies. Extensive analyses of these issues were undertaken by the
Agency in the course of previous rulemaking efforts for radon and other radionuchdes. Using
data provided by stakeholders, and from published literature, the EPA has updated these
technical analyses to take into account the best currently available information and ^ respond to
comments on the 1991 proposed regulation for radon in drinking water. As required by the 1996
Safe Drinking Water Act (SDWA), EPA has withdrawn the proposed regulation for radon in
drinking water (US EPA 1997B) and will propose a new regulation by August, 1999. The
second Analysis (that of the MMM implementation scenarios) is presented in Section 9.
One of the most important inputs used by EPA in the RIA is the National Academy of
Sciences (NAS) 1999 report "Risk Assessment of Radon in Drinking Water" (NAS Report).
EPA has used the NAS assessment of the cancer risks from radon in drinking water to estimate
both the health risks posed by existing levels of radon in drinking water and also to estimate the
number of cancer deaths potentially prevented by reducing radon levels. The NAS Report is the
most comprehensive accumulation of scientific data gathered to date on radon in drinking water.
SDWA required the NAS assessment, which generally affirms EPA?s earlier scientific
conclusions and analyses on the risks of exposure to radon and its progeny in drinking water.
The analysis presented in this RIA uses updated estimates of the number of active public
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drinking water systems obtained from EPA's Safe Drinking Water Information System
(SDWIS). Treatment costs for the removal of radon from drinking water also have been updated.
The HRRCA follows EPA policies with regard to the methods and assumptions used in cost and
benefit assessment.
In updating key analyses and developing the framework for the cost-benefit analysis
presented in the HRRCA, EPA has consulted with a broad range of stakeholders and technical
experts. Participants in a series of stakeholder meetings held in 1997, 1998, and 1999 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, CO in November of 1997 to review
treatment technology costing approaches. The panel made a number of recommendations for
modification of 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.
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. EPA also held a series of conference calls with State drinking water
and indoor air programs to discuss issues related to developing guidelines for multimedia
mitigation programs.
2.2 Regulatory History
Section 1412 of the Safe Drinking Water Act (SDWA), as amended in 1986, requires the
EPA to publish Maximum Contaminant Level Goals (MCLGs) and to promulgate National
Primary Drinking Water Regulations (NPDWRs) for contaminants that may cause an adverse
effect on human health and that are known or anticipated to occur in public water supplies. In
response to this charge, the EPA proposed NPDWRs for radionuclides, including radon, in 1991
(US EPA 1991). The proposed rule included a maximum contaminant level (MCL) of 300 pCi/1
for radon in drinking water, applicable to both community water systems and non-transient non-
community water systems. A community water system (CWS) is defined as a public water
system with at least 15 or more service connections or that regularly serves at least 25 year-round
residents. A non-transient non-community system (NTNCWS) is a public water system that is
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not a CWS and that regularly serves at least 25 of the same persons for at least six months per
year Examples of NTNCWSs include those that serve schools, offices, and commercial
buildings. Under the proposed rule, all CWSs and NTNCWSs relying on ground water would
have been required to monitor radon levels quarterly at each point of entry to the distribution
system. Compliance monitoring requirements were based on the arithmetic average of four
quarterly samples. The 1991 proposed rule required systems with one or more points of entry
out of compliance to treat influent water to reduce radon levels below the MCL or to secure
water from another source below the MCL.
The proposed rule was accompanied by an assessment of regulatory costs and economic
impacts, as well as an assessment of the risk reduction associated with implementation of the
MCL. The Agency received substantial comments on the proposal and its supporting analyses
from States, water'utilities, and other stakeholder groups. Comments from the water industry
questioned EPA's estimates of the number of systems that would be out of compliance with the
proposed MCL, as well as the cost of radon mitigation. EPA's Science Advisory Board (SAB)
provided extensive comments on the risk assessment used by the Agency to support the proposed
MCL. The SAB recommended that EPA expand the analysis of the uncertainty associated with
the risk and risk reduction estimates. In response to these comments, the assessment was revised
twice, once in 1993 and again in 1995 (US EPA 1995). Both of the revised risk analyses
provided detailed quantitative uncertainty analysis.
2.3 Economic Rationale
This section of the RIA discusses the statutory authority on the economic rationale for
choosing a regulatory approach to protect public health from drinking water contamination. The
economic rationale is provided in response to Executive Order 12866. Regulatory Planning and
Review, which states,
[E]ach agency shall identify the problem that it intends to address
(including, where applicable, the failures of the private markets or
public institutions that warrant new agency action) as well as
assess the significance of the problem (Sect. 1 b(l)).
In addition, OMB guidance dated January 11, 1996, states that "in order to establish the
need for the proposed action, the analysis should discuss whether the problem constitutes a
significant market failure (p.3)." Therefore, the economic rationale laid out in this section should
not be interpreted as the Agency's approach to implementing the Safe Drinking Water Act.
Instead, it is the Agency's economic analysis, as required by the Executive Order, to support a
regulatory approach to the public health issue at hand.
2.3.1 Statutory Authority for Promulgating the Rule
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The 1996 reauthorization for the Safe Drinking Water Act (SDWA) mandated new
drinking water requirements. EPA's general authority to set Maximum Contaminant Level
Goals (MCLGs) and the National Primary Drinking Water Rule (NPDWR) was modified to
apply to contaminants that "may have an adverse effect on the health of persons," are "known to
occur or there is a substantial likelihood that the contaminant will occur in public water systems
with a frequency and at levels of public health concern," and for which "in the sole judgement of
the Administrator, regulation of such contaminant presents a meaningful opportunity for health
risk reductions for persons served by public water systems" (1996 SDWA. as amended).
The 1996 SDWA Amendments also require the promulgation of the Radon Rule by
August 1999. In addition, the 1996 Amendments require EPA to promulgate a Final Radon Rule
by August 2000.
23.2 The Economic Rationale for Regulation
In addition to the statutory directive to regulate radon in drinking water, there is also
economic rationale for government regulation. The need for government regulation often results
from an imperfection in the market's ability to provide safe water at price levels that efficiently
satisfy consumer needs. In a perfectly competitive market, market forces guide buyers and
sellers to attain the best possible social outcome. A perfectly competitive market occurs when
there are many producers of a product selling to many buyers, and both producers and consumers
have complete knowledge regarding the products of each firm. There must also be no barriers to
entry in the industry, and firms in the industry must not have any advantage over potential new
producers. Several factors in the public water supply industry do not satisfy the requirements for
a perfect market and lead to market failures that require regulation.
First, the public water market is a very limited competitive market with monopolistic
tendencies. These monopolies tend to exist because it is not economically efficient to have
multiple suppliers competing to build multiple systems of pipelines, reservoirs, wells, and other
facilities. Instead, a single firm or government entity performs these functions under public
control. Under monopolistic conditions, consumers are provided only one level of service with
respect to the quality attribute of the product, in this case drinking water quality. If they do not
believe the margin of safety in public health protection is adequate, they cannot simply switch to
another water utility.
Second, there are high information and transaction costs that impede public
understanding of the health and safety issues concerning drinking water quality. The type of
health risks potentially posed by trace quantities of drinking water contaminants involve analysis
and distillation of complex toxicological data and health sciences. EPA's Consumer Confidence
Report (CCR) rule (63 FR 44512) will make water quality information more easily available to
consumers. The CCR rule requires community water systems to mail their customers an annual
report on local drinking water quality. However, consumers will still have to analyze this
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information for its health risk implications. Even if informed consumers are able to engage
utilities regarding these health issues, the costs of such engagement-transaction costs (measured
in personal time and commitment) present another significant impediment to consumer
expression of risk preference.
SDWA regulations are intended to provide a level of protection from exposure to
drinking water contaminants that would not otherwise occur in the existing market environment
of public water supply. The regulations set minimum performance requirements for all public
water supplies in order to protect all consumers from exposure to contaminants. SDWA
regulations are not intended to restructure flawed market mechanisms or to establish competition
insupply. While these distortions are essential conditions in weighing perceptions of benefits
and costs, SDWA regulations do not attempt to correct market imperfection directly. Rather,
SDWA standards establish the level of service to be provided in order to better reflect public
preferences for safety. The Federal regulations remove the high information and transaction
costs by acting on behalf of all consumers in balancing the risk reduction and the social costs of
achieving this reduction.
2.4 Safe Drinking Water Act Amendments of 1996
In the 1996 Amendments to the Safe Drinking Water Act, Congress established a new
charter for public water systems, States, and EPA to protect the safety of drinking water supplies.
Among other mandates, amended Section 1412(b)(13) directed EPA to withdraw the drinking
water standards proposed for radon in 1991 and to propose a new MCLG and NPDWR for radon
by no later than August 6, 1999. As noted above, the amendments require NAS to conduct a risk
assessment for radon in drinking water and an assessment of risk reduction benefits from various
mitigation measures to reduce radon in indoor air (Section 1412(b)(13)(B)). In addition, the
amendments introduce two new elements into the radon in drinking water rule: (1) an Alternative
Maximum Contaminant Level (AMCL) and (2) multimedia radon mitigation (MMM) program.
If the MCL established for radon in drinking water is more stringent than necessary to
reduce the contribution to radon in indoor air from drinking water to a concentration that is
equivalent to the national average concentration of radon in outdoor air, EPA is required to
simultaneously establish an AMCL that would result in a contribution of radon from drinking
water to radon levels in indoor air equivalent to the national average concentration of radon in
outdoor air (Section 1412(b)(13)(F)). If an AMCL is established, EPA is to publish guidelines
for State programs, including criteria for multimedia measures to mitigate radon levels in indoor
air, to comply with the AMCL.
States may develop and submit to EPA for approval an MMM program to decrease radon
levels in indoor air (Section 1412(b)(13)(G)). These programs may rely on a variety of
mitigation measures, including public education, testing, training, technical assistance,
remediation grants and loan or incentive programs, or other regulatory and non-regulatory
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measures. EPA shall approve a State's program if it is expected to achieve equal or greater
health risk reduction benefits than would be achieved by compliance with the more stringent
MCL. If EPA does not approve a State program, or a State does not propose a program, public
water supply systems may propose their own MMM programs to EPA, following the same
procedures outlined for States. Once the MMM programs are established, EPA is required to re-
evaluate them no less than every five years.
2.5 Specific Requirements for the Health Risk Reduction and Cost Analysis
Section 1412(b)(13)(C) of the 1996 Amendments requires EPA to prepare a Health Risk
Reduction and Cost Analysis (HRRCA) to be used to support the development of the radon
NPDWR. SDWA requires the HRRCA be published for public comment by February 6, 1999,
six months before the rule is to be proposed. In the preamble of the proposed rule, EPA must
include a response to all significant public comments on the HRRCA.
The HRRCA must also satisfy the requirements established in Section 1412(b)(3)(C) of
the amended SDWA. According to these requirements. EPA must analyze each of the following
when proposing an NPDWR that includes a MCL: (1) quantifiable and non-quantifiable health
risk reduction benefits for which there is a factual basis in the rulemaking record to conclude that
such benefits are likely to occur as the result of treatment to comply with each level; (2)
quantifiable and non-quantifiable health risk reduction benefits for which there is a factual basis
in the rulemaking record to conclude that such benefits are likely to occur from reductions in co-
occurring contaminants that may be attributed solely to compliance with the MCL, excluding
benefits resulting from compliance with other proposed or promulgated regulations; (3)
quantifiable and non-quantifiable costs for which there is a factual basis in the rulemaking record
to conclude that such costs are likely to occur solely as a result of compliance with the MCL,
including monitoring, treatment, and other costs, and excluding costs resulting from compliance
with other proposed or promulgated regulations; (4) the incremental costs and benefits associated
with each alternative MCL considered; (5) the effects of the contaminant on the general
population and on groups within the general population, such as infants, children, pregnant
women, the elderly, individuals with a history of serious illness, or other subpopulations that are
identified as likely to be at greater risk of adverse health effects due to exposure to contaminants
in drinking water than the general population; (6) any increased health risk that may occur as the
result of compliance, including risks associated with co-occurring contaminants; and (7) other
relevant factors, including the quality and extent of the information, the uncertainties in the
analysis, and factors with respect to the degree and nature of the risk.
To the extent possible, this HRRCA follows the new cost-benefit framework being
developed by the Office of Ground Water and Drinking Water (OGWDW). As provided in the
SDWA, as amended, the HRRCA discusses the costs and benefits associated with a variety of
radon levels. Summary tables and figures are presented that characterize aggregate costs and
benefits, impacts on affected entities, tradeoffs between risk reduction and compliance costs, and
MMM implementation scenarios. More in-depth discussions of input data and assumptions are
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provided in the appendices to this document.
2.6 Document Structure
The HRRCA is organized into 10 sections and a number of appendices. Section 3
discusses the health effects of exposure to radon. Section 4 contains a discussion of regulatory
alternatives and the selected alternatives. Section 5 discusses the baseline assumptions in this
analysis and provides an industry profile. Section 6 describes the assumptions and methods for
estimating quantifiable benefits and assessing non-quantifiable benefits. Section 7 discusses the
water treatment and MMM methods used to calculate the national costs of the various radon
levels examined. Section 8 provides a discussion of the economic impacts of the proposed radon
rule on governments and business units, as well as low-income and minority populations.
Section°9 estimates the costs and benefits of various scenarios in which States and water systems
elect to develop and implement a MMM program and comply with the AMCL. Section 10
presents the results of the cost and benefit analysis, assuming 100% compliance with the MCL,
of reducing radon levels in drinking water, and evaluates economic impacts on households. In
addition the major sources of uncertainty associated with the estimates of costs, benefits, and
economic impacts are identified. Appendices provide details of the risk calculations; cost curves
for treatment technologies; methods used to calculate system flows; detailed breakdown
summaries of the cost, benefit and impact calculations; additional MMM scenario cost and
benefit tables for MCL levels of 100, 500, 700, 1000, 2000, and 4000 pCi/1; and benefit and cost
calculations for NTNCWSs.
3. HEALTH EFFECTS OF RADON EXPOSURE
This section presents an overview of the major issues and assumptions addressed in order
to characterize the health impacts and potential benefits of reductions in radon exposures. The
methods that have been used to characterize risk and benefits in the HRRCA are also described.
The assumptions and methods presented below are used in Section 10 to derive detailed
estimates of the health reduction benefits of different radon levels in ground water supplies.
3.1 Radon Occurrence and Exposure Pathways
As part of the regulatory development process, EPA has updated and refined its analysis
of radon occurrence patterns in ground water supplies in the United States (US EPA 1998L).
This new analysis incorporates information from the EPA 1985 National Inorganic and
Radionuclides Survey (NIRS) of 1000 community ground water systems throughout the United
States, along with supplemental data provided by the States, water utilities, and academic
researchers.
The new study also addressed a number of issues raised by public comments on the
previous occurrence analysis. These include characterization of regional and temporal variability
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in radon levels, variability in radon levels across different-sized water systems, variability of
radon levels among wells in individual systems, impact of sampling point, and the proper
statistical techniques for evaluating the data.
3.1.1 Occurrence
Radon is a naturally occurring volatile gas formed from the normal radioactive decay of
uranium. It is colorless, odorless, tasteless, chemically inert, and radioactive. Uranium is present
in small amounts in most rocks and soil, where it decays to other products including radium, then
to radon. Some of the radon moves through air or water-filled pores in the soil to the soil surface
and enters the air, while some remains below the surface and dissolves in ground water (water
that collects and flows under the ground's surface). Due to their very long half-life (the time
required for half of a given amount of a radionuclide to decay), uranium and radium persist in
rock and soil.
Radon itself undergoes radioactive decay and has a radioactive half-life of about four
days. When radon atoms decay they emit radiation in the form of alpha particles, and transform
into decay products, or progeny, which also decay. Unlike radon gas, these progeny easily attach
to and can be transported by dust and other particles in air. The decay of progeny continues until
stable, non-radioactive progeny are formed. At each step in the decay process, radiation is
released. The term radon, as commonly used, refers to radon-222 as well as its radioactive decay
products.
In general, radon levels in ground water in the United States have been found to be the
highest in New England and the Appalachian uplands of the Middle Atlantic and Southeastern
States (Figure 3-1). There are also isolated areas in the Rocky Mountains, California, Texas, and
the upper Midwest where radon levels in ground water tend to be higher than the United States
average. The lowest ground water radon levels tend to be found in the Mississippi Valley, lower
Midwest, and Plains States. When comparing radon levels in ground water to radon levels in
indoor air at the State level, the distribution of radon concentrations in indoor air (Figure 3-2) do
not always mirror distributions of radon in ground water.
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Figure 3-1. General Patterns of Radon Occurrence in Groundwater in the United States
General Patterns of Radon Occurrence in Groundwater in the United States
Mean Radon in Groundwater
pCW
Source: USEPA NIRS Survey, 1985 ,
Note: State averaging of data may obscure local variations in radon levels.
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Figure 3-2. EPA Map of Radon Zones in Indoor Air
EPA Map of Radon Zones
^ n*.' ^Vi >tt£p W itASltert«r(fcf *tK" Jktr J^JtUTtf oaf lUCl vl Jf^f SI
Legend Key:
Zone 1 - Counties have a predicted average indoor screening level greater than 4 pCi/1.
Zone 2 - Counties have a predicted average indoor screening level between 2 and 4 pCi/1.
Zone 3 - Counties have a predicted average indoor screening level less than 2 pCi/1.
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In addition to large-scale regional variation, radon levels in ground water also vary
significantly over smaller distance scales. Local differences in geology tend to greatly influence
the patterns of radon levels observed at specific locations (e.g., not all radon levels in New
England are high; not all radon levels in the Gulf Coast region are low). Over small distances,
there is often no consistent relationship between measured radon levels in ground water and
radium levels in the ground water or in the parent bedrock (Davis and Watson 1989). Similarly,
no significant national correlation has been found between rado)i levels in individual ground
water systems and the levels of other inorganic contaminants or conventional geochemical
parameters Potential correlations between radon levels and levels of organic contaminants in
ground water have not been investigated, but there is little reason to believe any would be found.
Radon's volatility is rather high compared to its solubility in water. Thus, radon volatilizes
rapidly from surface water, and measured radon levels in surface water supplies are generally
insignificant compared to those found in ground water.
Because of its short half life, there are relatively few man-made sources of radon
exposure in ground water. The most common man-made sources of radon ground water
contamination are phosphate or uranium mining or milling operations and wastes from thorium
or radium processing. Releases from these sources can result in high ground water exposures,
but generally only to very limited populations; for instance, to persons using a domestic well in a
contaminated aquifer as a source of potable water (US EPA 1994B).
Table 3-1 summarizes the regional patterns of radon in drinking water supplies as seen in
the NIRS database. This survey of 1,000 ground water systems, undertaken by EPA in 198s,
provides the most representative national characterization of radon levels in drinking water.
However, the NIRS has the disadvantage that the samples were all taken from within the
water distribution systems, making estimation of the naturally occurring influent radon levels
difficult. In addition, the NIRS data provide no information to allow analysis of the variability ot
radon levels over time or within individual systems.
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Table 3-1. Radon Distributions by Region (All System Sizes)
Region
Appalachian
California
Gulf Coast
Great Lakes
New England
Northwest
Plains
Rocky Mountains
Arithmetic Mean
(PCi/l)
1,127
629
263
278
2,933
222
213
607
Geometric Mean*
(pCi/1)
333
-» -» -»
_>_>j>
125
151
1,214
161
132
361
Geometric Standard
Deviation**
(pCi/l)
4.76
3.09
3.38
3.01
3.77
2.23
2.65
2.77
Source: US EPA 1998L. The values given are not population-weighted, but reflect averages across systems.
* The geometric mean is the anti-log of the average of the logarithms (log base e) of the observations.
** The geometric standard deviation is the anti-log of the standard deviation of the logarithms (log base e) of the
observations.
The NIRS data illustrate the wide regional variations in radon levels in ground water. The
arithmetic mean and geometric mean radon levels are substantially higher in New England and
the Appalachian region (in this analysis, all the States on the east coast between New York and
Florida) than in other regions of the United States. The large differences between the geometric
(anti-log of the average of the logarithms (log base e) of the observations) and arithmetic means
indicate how ''skewed" (i.e., "stretched" in a positive direction; a bell-shaped curve with a tail
out to the right) the radon distributions are. The Agency selected a lognormal model as the best
approach to evaluating these data.
EPA's current re-evaluation of radon occurrence in ground water uses data from a
number of additional sources to supplement the NIRS information and to develop estimates of
the national distribution of radon in ground water systems of different sizes. Data from 17 States
were used to evaluate the differences between radon levels in ground water and radon levels in
distribution systems in the same regions. The results of these comparisons were used to estimate
national distributions of radon occurrence in ground water. Where State data were not available,
the national average ratios of the NIRS (distribution system) to the State (well head) data were
used to adjust the NIRS data so that it is more representative of radon occurrence in groundwater
sources. Table 3-2 summarizes EPA's latest characterization of the distributions of radon levels
in ground water supplies of different sizes and populations exposed to radon through CWSs.
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In this table radon levels and populations are presented, for systems serving various
population ranges from 25 to greater than 100,000. For purposfe of estimating costs and benefits,
the CWSs are aggregated to be consistent with the following system size categories identified in
the 1996 SDWA, as amended: very very small systems (25-500 people), further subdivided into
75-100 and 101-500; very small systems (501-3,300 people); small systems (3,301-10,000
people); medium systems (10,001-100,000 people); and large systems (greater than 100,000
people).
In the updated occurrence analysis, insufficient data were available to accurately assess
radon levels in the highest CWSs size stratum. Thus, data from the two largest size strata were
pooled to develop exposure estimates for the risk and benefits assessments.
The Agency estimates that approximately 89.7 million people are served by community
around water systems in the United States based on an EPA analysis of SDWIS data in 1998.
The data in Table 3-2 show that systems serving more than 500 people account for approximately
95 percent of the population served by ground water systems, even though they represent only 40
percent the total active systems (USEPA 1997A). The estimated system geometric mean radon
levels range from approximately 120 pCi/1 for the largest systems to 312 pCi/1 for the smallest
systems. Arithmetic mean values for the various size categories range from 175 pCi/1 to 578
pCi/1, and the population-weighted arithmetic mean radon level across all the community ground
water supplies is 213 pCi/1.
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Table 3-2. Radon Distributions in Public Water Systems
II 1 System Size (Population Served)
II Total Systems
Geometric Mean Radon
1 Level, pCi/1
I Geometric Standard
1 Deviation
1 Arithmetic Mean
Population Served
(Millions)
1 Radon Level, pCi/l
| 100
J 300
|J500
|J700
1 1000
1 2000
|4000
25-100
1
14,651
312
3.0
578
0.87
101-500
14,896
259
3.3
528
3.75
501-
3,300
10,286
122
3.2
240
14.1
3,301-
10,000
2,538
124
2.3
175
14.3
>10,000
1,536
132
2.3
187
55.0
AH
Systems
43,907
232
3.0
442
88.1
Proportions of Systems Exceeding Radon Levels (percent)
84.7
51.4
33.6
23.4
14.7
4.7
1.1
78.7
45.1
29.1
20.3
12.9
4.4
1.1
56.9
22.1
11.4
6.8
3.6
0.8
0.1
60.4
14.3
4.6
1.8
0.6
0.0
0.0
62.9
16.2
5.5
2.3
0.8
0.1
0.0
74.0
39.0
24.2
16.5
10.2
4.9
0.8
Table 3-3 presents the total exposed population above each radon level by system size
category. Approximately 20% of the total population for all system sizes are above the radon
level of 300 pCi/1 and 63% are above a radon level of 100 pCi/1.
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I aoie J-J
======
ladon
evel
pCi/1)
4,000 .
2,000
1,000
700
500
300
100
>. roputauu
Very
Very
Small
25-100
9.4
41
128
202
290
445
733
II d.vpua^vt t
Very
Very
Small
101-500
46
183
541
848
1,210
1,880
3,290
1 =
,
Very Small
501-3,300
20
119
513
962
1,620
3,140
8,080
—
Small
3,301-lOK
0.2
5.7
85.5
267
672
2,080
8.760
1 —^
^ •
Medium
10K-100K
0.9
21.7
289
859
2,070
6,060
23.400
1 ^
=======
Large
> 100K
0.4
11.0
147
436
1,050
3,070
11,900
1
=====
Total
77.2
381
1,695
3,558
6,893
16,641
56.054
IJ
Radon exposures also arise from non-transient non-community water systems
(NTNCWSs) The Agency estimates that approximately 5.2 million people use water from
NTNCWSs (US EPA 1998G). An analysis of SDWIS data in 1998 shows there are
approximately 19 500 active NTNCWSs in the United States. Over 96 percent of these systems
serve fewer than 1 000 people. EPA recently identified useful data on radon levels in NTNCWSs
from six States. A preliminary analysis of data from these States suggested that geometric mean
radon levels are approximately 60 percent higher in NTNCWSs than in CWSs in the same size
category.
There are currently no data which enable the agency to determine the extent to which the
populations exposed to radon from CWSs and NTNCWSs overlap. Some portion of individuals
exposed through a CWS at home may be exposed to radon from a NTNCWS at school or at
work. Similarly, the same populations may be exposed to radon from two different community
systems in the course of their normal daily activities. Further, in the case of NTNCWSs, it is
possible that the same individual could be exposed sequentially throughout their life to radon
from a series of different systems; at school, then at work, etc.
3.1.2 Exposure Path ways
People are exposed to radon in drinking water in three ways: from ingesting radon
dissolved in water; from inhaling radon gas released from water during household use; and from
inhaling radon progeny derived from radon gas released from water.
Typically indoor air contamination arising from soil gas accounts for the bulk of total ^
individual risk due to radon exposure (NAS 1999). Nationally, levels of radon in household air
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average approximately 1.25 pCi/1 (US EPA 1992A). Usually, the bulk of the radon enters indoor
air by diffusion from soils through basement walls or foundation cracks or openings. Radon in
domestic water generally contributes a small proportion of the total radon in indoor air. The
NAS recommends that EPA use the central estimate of a transfer factor of 1.0 pCi/1 for radon in
domestic water contributing IxlO'4 pCi/1 to indoor air. As an example, for a typical ground water
CWS with a radon level of 250 pCi/1, the predicted increment in indoor air activity would be
0.025 pCi/1. This is about 2 percent of the average indoor level, which is derived mostly from
soils.
As noted, the bulk of radiation exposure through inhalation comes from radon progeny.
which tend to bind to airborne particulates. When the particles are inhaled, they become
deposited in the respiratory tract, and further radioactive decay results in a radiation dose to the
respiratory epithelium. In contrast, when radon gas is inhaled, it is absorbed through the lung,
and much of this fraction remains in the body only a short time before being exhaled.
Direct ingestion of radon gas in water is the other important exposure pathway associated
with domestic water use. If water is not agitated or heated prior to consumption, the bulk (80 to
100 percent) of the radon may remain in the water and is consequently ingested with it (US EPA
1995). Heating, agitation (for example, by a faucet aerator), and prolonged standing cause radon
to be released and the proportion consumed to be reduced. After a person ingests radon in water,
the radon passes from the gastrointestinal tract into the blood. The blood then circulates the
radon to all organs of the body before it is eventually exhaled from the lungs. When radon and
its progeny decay in the body, the surrounding tissues are irradiated by alpha particles. However,
the dose of radiation resulting from exposure to radon gas by ingestion varies from organ to
organ. Stomach, followed by the tissues of colon, liver, kidney, red marrow, and lung appear to
receive the greatest doses.
Exposure patterns to radon vary with different exposure settings. Depending on the
relative radon levels in water and air, water use patterns, and exposure frequency and duration,
the relative contribution of ingestion and inhalation exposure to total risks will vary. In the case
of domestic water use, inhalation of radon progeny accounts for most of the total individual risk
resulting from radon exposure (Section 3.2). Inhalation exposure to radon from NTNCWSs is
expected to be less than for CWSs, however, because exposures at these facilities tend to be less
frequent and of shorter duration than exposure from CWSs. Therefore, overall exposures at
NTNCWSs will likely be lower.
3.2 Nature of Health Impacts
Exposure to radon and its progeny is believed to be associated with increased risks of
several kinds of cancer. When radon or its progeny are inhaled, lung cancer accounts for most of
the total incremental cancer risk (NAS 1998 A). Ingestion of radon in water is suspected of being
associated with increased risk of tumors of several internal organs, primarily the stomach (NAS
1999). As discussed previously, NAS recently estimated the lifetime unit fatal cancer risks
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associated with exposure to radon from domestic water use for ingestion and inhalation
nathways EPA has also conducted a separate risk assessment which builds on the NAS findings.
The lifetime unit fatal cancer risk is defined as the lifetime risk associated with exposures to a
unit concentration (1 PCi/l) of radon in drinking water. EPA has also conducted its own risk
assessment building on the NAS findings. The results of these analyses are summarized in Table
3-4.
Table 3-4. Estimated Radon Unit Lifetime Fatal Cancer Risks in
Community Water Systems
Proportion of Total Risk
(Percent)
Cancer Unit Risk per pCi/1 in ,
Water
Inhalation of radon progeny
Ingestion of radon1
Inhalation of radon gas-
Total
7.0X10'8
6.3X10-'
6.7X10-
11
100
i^_
2. Source: C^lcutated by EPA from radiation dosimetry data and risk coefficients provided by NAS (NAS 1999).
These updated risk estimates indicate that inhalation of radon progeny accounts for most
(approximately 88 percent) of the individual risk associated with domestic water use with almost
all of the remainder (11 percent) resulting from ingestion of radon gas. Inhalation of radon
'progeny is associated primarily with increased risk of lung cancer, while ingestion exposure is
associated primarily with elevated risk of stomach cancer. Ingestion of radon also results in
slightly increased risk cancer of the colon, liver, and other tissues. Inhalation of radon gas is
estimated to account for approximately 1 percent of the total risk from household radon
exposures, and the major target organ is again believed to be the lung. EPA has also estimated
that the unit risk for individuals exposed to radon from CWSs in non-residential settings to be
1.4X10-7. This estimate, which is highly uncertain, would add approximately 18 percent to the
total radon risks from CWSs. :
In the following sections, methods and parameter values developed by the NAS and EPA
are applied to the estimation of baseline population risks and the levels of risk reduction
associated with the different radon levels. For the purposes of this Health Risk Reduction and
Cost Analysis EPA is using the best estimates of radon inhalation and ingestion risks provided
by the NAS Report. In order to finalize the Agency's estimate of lung cancer deaths arising from
indoor air exposure, EPA's Office of Radiation and Indoor Air is currently assessing various
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factors integral to the approach for estimating the lung cancer risks of inhaling radon progeny in
indoor air provided in the NAS 1998 report -The Health Effects of Exposure to Radon-BEIR VI"
(BEIR VI Report). This assessment will be reviewed by the Agency's SAB and may result in
some adjustment to the estimated unit risk, and its associated uncertainty, for inhalation of radon
progeny used in this HRRCA.
Radon, a noble gas, exhibits no other known toxic effects besides carcinogenesis. The
1998 NAS report indicates that there is no scientific evidence to show that exposure to radon is
associated with reproductive or genetic toxicity. Therefore, the endpoints characterized in the
risk assessment for radon exposure are primarily increased risk of lung and stomach cancers.
3.3 Impacts on Sensitive Subpopulations
Populations that might experience disproportionate risk as a result of radon exposure fall
into two general classes: those who might receive higher exposures per unit radon in water
supplies and those who are more sensitive to the exposures they receive. The former group
includes persons whose domestic water supplies have high radon levels, and whose physiological
characteristics or behaviors (high metabolic rate, high water consumption, large amounts of time
spent indoors) result in high exposures per unit of exposure concentration. As noted above, a
portion of the population could be exposed to radon from more than one source. For example, a
student or worker might be exposed to radon from the CWS in the household setting and also'
from a NTNCWS (or from the same or different CWS) at school or work.
Different age and gender groups may also experience exposure dosimetric differences.
These differences in radiation dose per unit exposure have been taken into account in the BEIR
VI Report addressing radon in indoor air (NAS 1998A), the NAS Report addressing radon in
drinking water (NAS 1999), and the EPA Federal Guidance Report 13 (US EPA 1998F).
The NAS Report concluded that there is insufficient scientific information to permit
separate cancer risk estimates for Subpopulations such as pregnant women, the elderly, children,
and seriously ill persons. The report did note, however, that according to the NAS risk model for
the cancer risk from ingested radon, which accounts for 11% of the total lifetime fatal cancer risk
from radon in drinking water, approximately 30% of this fatal lifetime cancer risk is attributed to
exposure between ages 0 to 10.
The NAS identified smokers as the only group that is more susceptible to inhalation
exposure to radon progeny. Inhalation of cigarette smoke and radon progeny result in a greater
increased risk than if the two exposures act independently to induce lung cancer.
3.4 Risk Reduction Model for Radon in Drinking Water
Risk and risk reduction were estimated using Monte Carlo models that simulated the
initial and post-regulatory distributions of radon activity levels and individual risks. Each
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iteration of the model selected a size stratum of community water systems. The sy stemsizes
were stratified according to the following populations served: ;<100; lOloOO *1^™'
3 301-10.000; and > 10.000 served. For each size category, a lognormal distribution of
uncontrolled radon levels had been defined based on the updated occurrence <^s»
1998L) The model sampled randomly from the radon distribution for the selected CWS size
category to determine if the radon level was above the selected maximum exposure level.
In each iteration of the model, the simulated influent radon activity level was compared^to
the maximum radon levels under consideration (100, 300, 500,700, 1000, 2000 and 4000 pCi/1).
When the simulated influent radon level was less than the target level the simulated leve was
passed directly to the risk calculation equations. The equations calculated individual fatal cancer
rfsks from ingestion of radon gas, inhalation of radon gas and inhalation " P^*3^
standard exposure factors and unit risk values derived as described above by NAS and EPA.
When the simulated influent radon level in a given iteration exceeded a target radon level,
the model reduced the value by a proportion equivalent to the performance of selected mitigation
technologies. The degrees of reduction are presented in Table-So:
Table 3-5. Radon Treatment Assumptions
If the Radon Level is:
—
Less than the target level
Above but less than two times the target level
to Calculate Residual Fatal Cancer Risks
Above two times but less than five times the
target level
Greater than five times the target level
Then the Treated Level is:
None; Influent = Effluent
Influent = 0,5 * Effluent
Influent = 0.2 * Effluent
Influent = 0.01 * Effluent
Usina this approach implies that a greater level of control is achieved than if all the
systems were simply assumed to reduce exposures to the maximum exposure level. For
example a system with an initial uncontrolled concentration of 400 pCi/1 would need to employ
a mitioation technology with a 50 percent removal efficiency to comply with a maximum
exlsure limit of 300 pCi/1, resulting in a final radon level of 200 pCi/1. Limited sensitivity
analysis indicates that this approach does not provide very much in the way of extra risk
reduction The preponderance of risk reduction is achieved by reducing radon levels in the
relatively few systems that have initial uncontrolled values far above the maximum exposure
limits, not by the relatively small incremental reductions below the target radon levels.
To estimate population risks, the distribution of individual risks for a given size category
of systems was multiplied by the estimated number of individuals whose homes were served by
systems of that size. The risks associated with non-residential exposures from community water
systems were not included in the calculation due to the very high uncertainty surrounding the
September, 1999 - Draft Document
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estimates of exposures and populations exposed.
3.5 Risks from Existing Radon Exposures
In support of the regulatory development process for the revised radon rule, EPA has
updated its risk assessment for radon exposures in drinking water. Previously, EPA developed
estimates of risk from total population exposure to radon in drinking water in support of the
proposed rule for radon in 1991 (US EPA 1991). In response to comments from the SAB, EPA
updated the risk assessment to include an analysis of uncertainty in 1993 (US EPA 1993B). The
assessment was further revised to include revisions to risk factors and other variable values. The
latest uncertainty analysis was completed in 1995 (US EPA 1995).
Table 3-6 summarizes the results of EPA's revised baseline risk assessment. Because the
MAS and EPA-derived dose-response and exposure parameters factors discussed above were
used in the risk assessment, the proportions of risk associated with the various pathways are the
same as shown in Table 3-4. The total estimated population risk associated with the current
distribution of radon in CWSs was 168 fatal cancers per year, 148 of which were associated with
progeny inhalation. Approximately 18 fatal cancers per year were associated with ingestion of
radon. These totals are similar to. but somewhat lower than, EPA's 1991 and 1993 baseline risk
estimates (USEPA 1994C). In comparison, there are an estimated 15,400 to 21,800 fatal lung
cancers per year due to inhalation of indoor air contaminated with radon emanating from soil and
bedrock (NAS 1998 A).
The risks summarized in Table 3-5 do not include any contribution from NTNCWSs.
NTNCWSs are not covered by the radon rule and thus are not included in this analysis.
Therefore, the potential baseline risks and benefits of a radon rule may be somewhat
underestimated. The limited available data concerning radon levels in NTNCWSs suggest that
levels may be considerably higher (perhaps by 60 percent, on average) than those in CWSs of
similar size (US EPA 1998L). However, it appears that the average exposure per unit activity in
NTNCWSs is likely to be lower than that for CWSs. Because of the expected lower inhalation
exposures, water ingestion rates, and frequencies and durations of exposure, the individual fatal
cancer risk associated with a NTNCWS is expected to be lower compared to a CWS with similar
radon levels. An analysis of the potential benefits and costs to NTNCWSs is shown in Appendix
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Table 3-6. Annual Fatal Cancer Risks for Exposures to Radon
from Community Water Systems
Pathway
Inhalation of progeny
Ingestion of radon gas
Inhalation of radon gas
Cancer Unit Risk per
pCi/1 in Water
5.9X10"
7.0X10';
Annual Population
Risk (Fatal cancers
per year)2
148
18
Proportion of Total
Annual Risk (Percent)
88
11
Notes- 1 Derived using NAS lifetime unit fatal cancer risks.
' 2. Estimated through simulation analysis described in Section 3.4: the risk equations and parameter values
used in the simulation analysis are summarized in Appendix A.
3.6 Potential for Risk Reductions Associated with Removal |of Co-Occurring Contaminants
Because radon is a naturally occurring ground water contaminant, its occurrence patterns
are not highly correlated with those of industrial pollutants. Similarly, the Agency's re-
evaluation of radon occurrence has revealed that the geographic patterns of radon occurrence are
not significantly correlated with naturally occurring inorganic contaminants that may pose health
risks. °Thus, it is not likely that a relationship exists between the need to install radon treatment
technologies and treatments to remove other contaminants. .
On the other hand, technologies used to reduce radon levels in drinking water have the
potential to reduce concentrations of other pollutants as well. All of the aeration technologies
discussed in Section 7 remove volatile organic contaminants, as well as radon, from
contaminated sround water. Similarly, GAC treatment for radon removal effectively reduces the
concentrations^ organic (both volatile and nonvolatile) chemicals and some inorganic
contaminants Aeration also tends to oxidize dissolved arsenic (a known carcinogen) to a less
soluble form that is more easily removed from water. The frequency with which radon treatment
would also reduce risks from other contaminants, and the extent of risk reduction that would be
achieved, has not been evaluated quantitatively in the HRRCA.
3.7 Potential for Risk Increases from Other Contaminants Associated with Radon Removal
As discussed in Section 7.2, the need to install radon treatment technologies may require
some systems that currently do not disinfect to do so. Case studies (US EPA 1998D) of twenty-
nine small to medium water systems that installed treatment (24 aeration, 5 GAC) to remove
radon from drinking water revealed only two systems that reported adding disinfection (both
aeration) with radon treatment (the other systems either had disinfection already in place or did
not add it) In practice, the tendency to add other disinfection with radon treatment may be much
September, 1999 - Draft Document
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more significant than these case studies indicate. EPA also realizes that the addition of
chlorination for disinfection may result in risk-risk tradeoffs, since, for example, the disinfection
technology reduces potential for infectious disease risk, but at the same time can result in
increased exposures to disinfection by-products (DBFs). This risk-risk trade-off is addressed by
the recently promulgated Disinfectants and Disinfection By-Products NPDWR (US EPA 19981).
This rule identified MCLs for the major DBPs, with which all CWSs and NTNCWSs must
comply. These MCLs set a risk ceiling from DBPs that water systems adding disinfection in
conjunction with treatment for radon removal could face. The formation of DBPs correlates with
the concentration of organic precursor contaminants, which tend to be much lower in ground
water than in surface water. In support of this statement, the American Water Works
Association's WATERSTATS survey reports that more than 50% of the ground water systems
surveyed have average total organic carbon. (TOC) raw water levels less than 1 mg/L and more
than 80% had TOC levels less than 3 mg/L. On the other hand. WATERSTATS reports that less
than 6% of surface water systems surveyed had raw water TOC levels less than 1 mg/L and more
than 50% had raw water TOC levels greater than 3 mg/L. In fact, this survey reports that more
than 85% of surface water systems had finished water TOC levels greater than 1 mg/L.
The NAS Report addressed several important potential risk-risk tradeoffs associated with
reducing radon levels in drinking water, including the trade-off between risk reduction from
radon treatment that includes post-disinfection with the increased potential for DBP formation
(NAS 1999). The report concluded that, based upon median and average total trihalomethane
(THM) levels taken from a 1981 survey, ground water systems would face an incremental
individual lifetime cancer risk due to chlorination byproducts of 5x10"5. It should be emphasized
that this risk is based on average and median Trihalomethane (THM) occurrence information that
does not segregate systems that disinfect from those that do. It should also be noted that this
survey pre-dates the promulgation of the Stage I Disinfection Byproducts Rule by almost twenty
years. Further, the NAS Report points out that this average DBP risk is smaller than the average
individual lifetime fatal cancer risk associated with baseline radon exposures from ground water
(untreated for radon), which is estimated at 1.2 x 10"4 using a mean radon concentration of 213
pCi/1.
While this risk comparison is instructive, a more meaningful relationship for the proposed
radon rule would be to compare the trade-off between radon risk reduction from radon treatment
and introduced DBP risk from disinfection added along with radon treatment. EPA emphasizes
that this risk trade-off is only of concern to the small minority (<1%) of small ground water
systems with radon levels above the AMCL of 4000 pCi/L and to the small minority of large
ground water systems that are not already disinfecting. Presently, approximately half of all small
community ground water systems already have disinfection in place, as shown in Table 5-4. The
proportion of systems having disinfection in place increases as the system's size increases; >95%
of large ground water systems currently disinfect. In terms of the populations served, 83% of
persons served by small community ground water systems (those serving 10,000 persons or
fewer) already receive disinfected drinking water and 95% of persons served by large ground
water systems already receive disinfected drinking water. As shown in Tables 3-7 and 3-8, even
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for those ground water systems adding both radon treatment and disinfection, this risk-risk trade-
off tends to be very favorable, since the risk reduction from radon removal greatly outweighs the
added risk from DBF formation.
An estimate of the risk reduction due to treatment of radon in water for various removal
percentages and finished water concentrations is provided in Table 3-7. These risk reductions are
much greater than NAS's estimate of the average lifetime risk from DBF exposure for ground
water systems, by factors ranging from 3.5 for low radon removal efficiencies (50%) to more
than 130 for higher radon removal efficiencies (>95%). ;
Table 3-7. Radon Risk Reductions Resulting from Water Treatment
Radon Influent (Raw Water) Level,
pCi/L
500
750
1000
2500
4000
10000
Required Removal
Efficiency
52%
68%
76%
90%
94%
98%
Reduced Lifetime Risk Resulting
from Water Treatment for Radon
in Drinking Water1
1.7 x IQ-1
3.4 x ID"1
5.1 x lO'4
1.5 x 10-
: 2.5 x 10-
6.5 x 10-
Notes- 1 ) Assumes that water is treated to 80% of the radon MCL.
Table 3-8 demonstrates the risk-risk trade-off between the risk reduction from radon
removal and the risks introduced from total trihalomethanes (TTHM) for two scenarios: 1) the
resulting TTHM level is 0.008 mg/L (10% of the TTHM MCL) and 2) the resulting TTHM level
is 0 080&mg/L (the TTHM MCL). The table demonstrates that the risk-risk trade-off is
favorable for treatment with disinfection, even for situations where radon removal efficiencies
are low (50%) and TTHM levels are present at the MCL. While accounting quantitatively for the
increased risk from DBF exposure for systems adding chlorination in conjunction with treatment
for radon may somewhat decrease the monetized benefits estimates, disinfection may also
produce additional benefits from the reduced risks of microbial; contamination.
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Table 3-8. Radon Risk Reduction from Treatment Compared to DBF Risks
Rat
(Raw
ion Influent
Water) Level,
pCi/L
500
750
1000
2500
4000
10000
Notes:
1)
2)
3)
4)
Estimated Risk Ratios:
(Lifetime Risk Reduction from Radon Removal1 / Lifetime Average Risk from
TTHiVUs in Chlorinated Groundwater)
(NAS)-
4
7
10
30
50
130
TTHMs Present at 10% of
TTHM MCL (0.080 mg/L)3
30
60
90
300
500
1200
TTHMs Present at MCL
3
6
9
30
50
120
From Table 3-7.
From Appendix D in: National Research Council. Risk Assessment of Radon in Drinking Water National
Academy Press. Washington. DC. 1999. DBF concentrations are from a 1981 study and therefore pre-date the
Stage 1 DBF NPDWR.
US EPA. Regulatory Impact Analysis for the Stage I Disinfectants/Disinfection Byproducts Rule. Prepared by
The Cadmus Group. November 12. 1998. Analysis is based on the 95% upper confidence interval value from
the Integrated Risk Information System (IRIS) lifetime unit risks for each THM. TTHM is assumed to
comprised by 70% chloroform. 21% bromodichloromethane. 8% dibromochloromethane. and 1% bromoform.
US EPA. Regulatory Impact Analysis for the Stage 1 Disinfectants/Disinfection Byproducts Rule. Based on
the 95% upper confidence interval value from the Integrated Risk Information System (IRIS) for the lifetime
unit risk for dibromochloromethane (2.4 x 1 0* risk of cancer case over 70 years of exposure).
3.8 Risk for Ever-Smokers and Never-Smokers
As noted previously, cancer risks from inhalation of radon progeny are believed to be
greater for current and former smokers than for "never smokers". The NAS defines a "never
smoker"' as someone who has smoked less than 100 cigarettes in their lifetime. Therefore, "ever
smokers" include current and former smokers. EPA and NAS have developed estimates of unit
risk values (estimates of cancer risks per unit of exposure) for radon progeny for ever-smokers
and never-smokers as shown in Table 3-9 (US EPA 1999D). The estimated unit risk values for
inhalation of radon progeny for ever-smokers (and therefore the individual and population risk) is
approximately 5.4 times greater than that for never smokers.
Because of estimated higher individual risks for smokers, this group accounts for a large
proportion of the overall population risk associated with radon progeny inhalation. The last two
columns of the table show that, given the current assumptions about smoking prevalence and the
relative impact of radon progeny on ever smokers and never smokers, about 84 percent of the
cancer cases from drinking water exposures to progeny will occur in the ever-smoker population.
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Table 3-9. Annual Lung Cancer Death Risk Estimates from Radon Progeny for Ever-
Smokers, Never-Smokers, and the General Population
Smoking
Status
Ever
Never
Combined
Annual Unit Risk
(Fatal cancer cases
per year per pCi/l
in water)
1.31X10-8
2.43X10-9
7.91X10-9
Average Annual
Individual Risk per
Year of Exposure
2.78X10-6
5.18X10-7
1.69X10-6
Annual Population
Risk (Fatal Cancers
peir Year)
123
'23
:148
Proportion of
Total Annual
Population Risk
84%
16%
100%
Source: EPA analyses derived from NAS (1998) estimates
Note: Ever-smoking prevalence was assumed to be 58 percent in males and;42 percent in females, and these rates
were assumed to be°age independent. Population risks do not add exactly because the NAS unit risks are expressed
to only 2 significant figures.
4. CONSIDERATION OF REGULATORY ALTERNATIVES
4.1 Radon Levels and Other Options Evaluated
The HRRCA is intended to present estimates of the potential costs and benefits of various
levels of controlling radon in drinking water and MMM implementation scenarios. The HRRCA
assumes that all systems drawing water from Sources above a defined radon level will employ
treatment technologies to meet the target level or "regionalize" to obtain water from another
source with lower radon levels. This analysis evaluates radon levels of 100, 300, 500, 700,
1,000. 2,000, and 4,000 pCi/l. The analysis of costs and benefits did not include any provisions
for exemptions or phased compliance. In the mitigation cost analysis described in Section 7, it is
conservatively assumed that all systems will be required to perform quarterly monitoring for the
entire compliance period, whereas for the analysis of paperwork requirements in Section 8,
quarterly, reduced, and confirmation sampling are considered. ••
Findings from this initial analysis indicated high compliance costs for small systems. To
reduce economic impacts to these small systems and the households they serve, EPA is
recommending that small systems comply with the AMCL and implement an MMM program.
For this reason, the HRRCA also evaluates national costs and benefits of MMM implementation
scenarios, 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 NAS recommendations, the AMCL level that is evaluated is 4,000 pCi/l.
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Under the scenarios that include an AMCL. the HRRCA assumes that a portion of the States
would adopt an AMCL supplemented with MMM programs to address indoor air radon risks. In
the absence of information concerning the number of States that would choose to implement
radon risk reduction through the use of AMCL plus multimedia programs, the HRRCA assumes
that 50, 60, 70. 80, and 95 percent of the States in the United States would choose to implement
MMM programs and comply with the AMCL. These issues are discussed in more detail in
Section 9.
4.2 Selected Regulatory Alternatives
A CWS must monitor for radon in drinking water in accordance with the regulations, as
described in Section VIII of the Preamble, and report their results to the State. If the State
determines that the system is in compliance with the MCL of 300 pCi/1, the CWS does not need
to implement a MMM program (in the absence of a State program), but must continue to monitor
as required.
As discussed in Section VI of the preamble. EPA anticipates that most States will choose
to develop a State-wide MMM program as the most cost-effective approach to radon risk
reduction. In this case, all CWSs within the State may comply with the AMCL of 4000 pCi/1.
Thus, EPA expects the vast majority of CWSs will be subject only to the AMCL. In those
instances where the State does not adopt this approach, the proposed regulation provides the
following requirements:
4.2.1 Requirements for Small Systems Serving 10,000 People or Less
The EPA is proposing that small CWSs serving 10.000 people or less must comply with
the AMCLr 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 the radon in
drinking water rulemaking. Further information supporting this certification is available in the
public docket for the rule.
EPA's regulation expectation for small CWSs is the MMM and AMCL because this
approach is a much more cost-effective way to reduce radon risk than compliance with the MCL.
(While EPA believes that the MMM approach is preferable for small systems in a non-MMM
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State, they may. at their discretion, choose the option of meeting the MCL of 300 pCi/L instead of
developing a local MMM program). The CWSs will be required to submit MMM program plans
to their State for approval. (See Sections VI.A and F of the preamble for further discussion of
this approach).
SDWA Section 1412(b)( 13)(E) directs EPA to take into account the costs and benefits of
programs to reduce radon in indoor air when setting the MCL.: In this regard, the Agency
expects that implementation of a MMM program and CWS compliance with 4000 pCi/1 will
provide greater risk reduction for indoor radon at costs more proportionate to the benefits and
commensurate with the resources of small CWSs. It is EPA's intent to minimize economic
impacts on a significant number of small CWSs, while providing increased public health
protection by emphasizing the more cost-effective multimediaiapproach for radon risk reduction.
4.2.2 Requirements for Large Systems Serving More Than 10,000 People
The proposal requires large community water systems.. those serving populations greater
than 10.000, to comply with the MCL of 300 pCi/1 unless the State develops a State-wide MMM
program, or the CWS develops and implements a MMM program meeting the four regulatory
requirements, in which case large systems may comply with the AMCL of 4,OOOpCi/l. CWSs
developing their own MMM plans will be required to submit these plans to their State for
approval.
4.2.3 Background on the Selection of the MCL and AMCL
The SDWA directs that if the MCL for radon is set at a level more stringent than the level
in drinking water that would correspond to the average concentration of radon in outdoor air,
EPA must also set an alternative MCL at the level corresponding to the average concentration in
outdoor air. Consistent with this requirement, EPA is proposing to set the AMCL at 4000 pCi/L.
This level is based on technical and scientific guidance contained in the NAS Report (NAS 1999)
on the water-to-air transfer factor of 10,000 pCi/L in water to :1 pCi/L in indoor air and the
average outdoor radon level of 0.4 pCi/L. :
The SDWA generally requires that EPA set the MCL for each contaminant as close as
feasible to the MCLG, based on available technology and taking costs to large systems into
account. The 1996 amendments to the SDWA added the requirement that the Administrator
determine whether or not the benefits of a proposed maximum, contaminant level justify the costs
based on the HRRCA required under Section 1412(b)(3)(C). They also provide new
discretionary authority to the Administrator to set an MCL less stringent than the feasible level if
the benefits of an MCL set at the feasible level would not justify the costs (SDWA section
EPA is proposing to set the MCL at 300 pCi/L, in consideration of several factors. First,
the Agency considered the general statutory requirement that the MCL be set as close as feasible
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to the MCLG of zero (SDWA section 1412(b)(4)), and its responsibility to protect public health.
In addition, the radon-specific provisions of the amendments provide that, in promulgating a
radon standard, the Agency take into account the costs and benefits of programs to control indoor
radon (SDWA 1412(b)(13)(E). Although EPA believes that an MCL of 100 pCi/L would be •
feasible, EPA believes that consideration of the costs and benefits of indoor radon control
programs allows the level of the MCL to be adjusted to a less stringent level than the Agency
would set using the SDWA feasibility test. The proposed MCL of 300 pCi/L takes into account
and relies on the unique conditions of this provision and the reality it reflects that the great
preponderance of radon risk is in air, not water, and the much more cost-effective alternative to
water treatment is to address radon in indoor air through the MMM program. The Agency
recognizes that controlling radon in air will substantially reduce human health risk in more cost-
effective ways than spending resources to control radon in drinking water. If the majority of
states adopted the MMM/AMCL option, EPA estimates the combined costs for treatment of
water at systems exceeding the AMCL, developing a MMM program, arid implementing
measures to get risk reduction equivalent to national compliance with the MCL (62 avoided fatal
cancer cases and 4 avoided non-fatal cancer cases per year) at approximately $80 million, which
is substantially less than the $407.6 million cost of achieving the MCL. EPA expects that most
states will adopt the AMCL/MMM program option. A detailed description of EPA's process for
selecting the MCL and AMCL is shown in Section VII.D of the preamble for the proposed rule.
5. BASELINE ANALYSIS
Data and assumptions used in establishing baselines for the comparison of costs and
benefits are presented in the next section. While the rule as proposed does not require 100%
compliance with an MCL, an analysis of these full compliance scenarios are required by the
SDWA, as amended, and were an important feature in the development of the NPDWR for
radon.
5.1 Industry Profile
Radon is found at appreciable levels only in systems that obtain water from groundwater
sources. Thus, only groundwater systems would be affected by the proposed rule. The following
sections address various characteristics of community groundwater systems that were used in the
assessment of regulatory costs and benefits.
5.1.1 Numbers and Sizes of Systems
Table 5-1 shows the estimated number of community groundwater systems in the United
States. This data originally came from EPA's Safe Drinking Water Information System
(SDWIS) and are summarized in EPA's Drinking Water Baseline Handbook (1999A). EPA
estimates that there were 43,908 community groundwater systems active in December 1997 when
the SDWIS data were evaluated. Approximately 96.5 percent of the systems serve fewer than
10,000 people, and thus fit EPA's definition of a "small" system. Privately-owned systems
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comprise the bulk of the smaller size categories, whereas most larger systems are publicly
owned.
5.1.2 Numbers of Sources Per System
In addition to the number of affected systems, the total number of sources (wells) is an
important determinant of potential radon mitigation costs. Larger systems tend to have larger
numbers of sources than small ones, and it has been assumed in the mitigation cost analysis that
each source out of compliance with the MCL or AMCL would need to install control equipment.
Table 5-2 summarizes the estimated number of wells per groundwater system. Both the
number of wells and the variability in the number of wells increases with the number of people
served. These characteristics of community groundwater sources are included in the mitigation.
cost analysis discussed in Section 7.
5.2 Baseline Assumptions
In addition to the characteristics of the groundwater suppliers, other important "baseline"
assumptions were made that affect the estimates of potential costs and benefits of radon
mitigation. Two of the most important assumptions relate to the distribution of radon in
groundwater sources and the technologies that are currently in place at groundwater systems to
control radon and other pollutants. :
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5.2.1 Distribution of Radon in Groundwater Systems
As noted in Section 3, EPA has recently completed an analysis of the occurrence patterns
of radon in groundwater supplies in the United States (US EPA 1998L). This analysis used the
NIRS and other data sources to estimate national distributions ofgroundwater radon levels in
community systems of various sizes. The results of that analysis are summarized in Table 5-3.
These distributions are used to calculate baseline individual and population risks, and to predict
the proportions of systems of various sizes that will require radon mitigation.
Table 5-3. Distribution of Radon Levels in U.S. Groundwater Sources
Statistic
Geometric
Mean, pCi/L
Geometric
Standard
Deviation,
pCi/L
Arithmetic
Population Served
25-100
312
3.04
578
101-500
259
3.31
528
501-3,300
122
3.22
240 :
3,301-10,000
124
2.29
175
> 10,000
132
2.31
187
5.2.2 Water Treatment Technologies Currently in Place :
The costs of radon mitigation are affected to some extent, by the treatment technologies
that are currently in place to mitigate radon and other pollutants, and by the existence of pre- and
post-treatment technologies that affect the costs or mitigation. EPA has conducted an extensive
analysis of water treatment technologies currently in use by groundwater systems (Table 5-4).
Table 5-4 shows the proportions of ground water systems with specific technologies already in
place, broken down by system size (population served). Many groundwater systems currently
employ disinfection, aeration, or Iron/Manganese removal technologies. This distribution of pre-
existing technologies serves as the baseline against which water treatment costs are measured.
For example, costs of disinfection are attributed to the radon rule only for the estimated
proportion of systems that would have to install disinfection as a post-treatment because they do
not already disinfect. i
The cost analysis assumes that any system affected by the rule will continue to employ
pre-existing radon treatment technology and pre- and post-treatment technologies in their efforts
to comply with the rule. Where pre- or post-treatment technologies are already in place it is
assumed that compliance with the radon rule will not require any upgrade or change in the pre- or
post-treatment technologies. Therefore, no incremental cost is attributed to pre- or post-
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treatment technologies. This may underestimate costs if pre- or post-treatment technologies need
to be changed (e.g., a need for additional chlorination after the installation of packed tower
aeration). The potential magnitude of this cost underestimation is not known, but is likely to be a
very small fraction of total treatment costs.
Table 5-4. Estimated Proportions of Groundwater Systems With Water Treatment
Technologies Already in Place (Percent)1
Water Treatment
Technologies in Place
Fe/Mn Removal &
Aeration & Disinfection
Fe/IVIn Removal &
Aeration
Fe/Mn Removal &
Disinfection
Fe/Mn Removal
Aeration & Disinfection
Only
Aeration Only
Disinfection Only
None
System Size (Population Served)
25-
100
0.4
0.0
2.1
1.9
0.9
0.8
49.6
44.3
101-
500 ,
0.2
0.1
5.1
1.5
3.2
1.0
68.2
20.7
501-
1K
1.2
0.2
8.3
1.5
9.8
1.8
65.0
"12.2
1K-
3.3K
0.6
0.1
3.0
1.0
13.7
2.9
65.0
13.7
3.3K-
10K
2.9
0.4
7.8
1.1
20.9
2.9
56.3
7.7
10K-
50K
2.2
O.I
7.4
0.4
19.7
1.0
66.0
3.2
50K-
100K
3.1
0.4
9.7
1.1
18.6
2.1
58.3
6.7
100K-
1M
2.0
0.1
6.8
0.2
19.9
0.6
68.3
2.1
I. Source: EPA analysis of data from the Community Water System Survey (CWSS). 1997. and Sate Drinkins Water Information
System (SDWIS). 1998.
6. BENEFITS ANALYSIS
6.1 Nature of Regulatory Benefits
I
6.1.1 Quantifiable Benefits
The benefits of controlling exposures to radon in drinking water take the form of avoided
cancers resulting from reduced exposures. Cancer risks (both fatal and non-fatal cancers per
year) are calculated using the risk model described in Section 3 for the baseline case (current
conditions) and each of the radon levels. The health benefits of controls are estimated as the
baseline risks minus the residual risks associated with each radon level. The more stringent the
radon level, the lower the residual risks, and the higher the benefits.
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The primary measures of regulatory benefits that are used in this analysis are the annual
numbers of fatal and non-fatal cancers prevented by reduced exposures.' In quantifying the health
risk reduction benefits, it has been assumed that risk reduction begins to accrue immediately after
the reduction in exposure.
Exposures to radon and its progeny are associated with increases in lung cancer risks.
Ingestion of radon in drinking water is suspected of being associated primarily with increased
risks of cancer of the stomach, and with lesser risks to the colon1 lung, and other organs. The
first column of Table 6-1 summarizes the estimates of the distribution of cancers by organ system
for inhalation and ingestion exposures given. For purposes of the risk assessment, inhalation of
progeny and radon gas are assumed to be associated exclusively; with lung cancer risk. In the
case of radon ingestion, stomach cancer accounts for the bulk (approximately 89 percent) of the
total risk by this pathway. Cancers of several other organ systems account for far smaller
proportions of the cancer risk from radon ingestion, and are not included in this analysis.
Table 6-1. Proportion of Fatal Cancers by Exposure Pathway and Estimated Mortali
Proportion of Fatal
Exposure Pathway II Organ Affected
Inhalation of progeny, radon gas
Ingestion of radon gas
Lung
Stomach
Colon
Liver
Lung
General Tissue
Cancers by Organ and
Exposure Pathway
(percent)'
89
9.5
0.4
0.2
0.2
0.5
Mortality
(percent)2
95
90
55
95
95
1. Source: US EPA analysis of dosimetry data and organ-specific risk coefficients (NAS 1998).
2. Source:. US EPA analysis of National Cancer Institute mortality data.
The last column of Table 6-1 provides estimates of the mortality rates (proportion of
individuals who ultimately die of the disease) associated with the various types of radon-
associated cancers. These values are used in this analysis to estimate the proportion of fatal and
non-fatal cancers by organ system and exposure pathway. Both of the cancers that account for
the bulk of the risk from radon and progeny exposures (lung and stomach) have high mortality
rates. Thus, far more fatal than non-fatal cancers are prevented by reductions in radon exposure.
6.1.2 Non-Quantifiable Benefits
Reductions in radon exposures might also be associated,with non-quantifiable benefits.
EPA has identified several potential non-quantifiable benefits associated with regulating radon in
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drinking water. These include any peace of mind benefits specific to reduction of radon
exposure that may not be adequately captured in the VSL estimate. In addition, if chlorination is
added to the process of treating radon via aeration, arsenic pre-oxidation 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, it has also
been suggested that 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 an MMM program. In the
case of the proposed radon rule, it is not likely that accounting for these non-quantifiable benefits
would significantly alter the overall assessment.
6.2 Monetization of Benefits
i
6.2.1 Estimation of Fatal and Non-Fatal Cancer Risk Reduction
i i
The "direct" health benefits of the regulation, as discussed above, are the reduced streams
of cancer cases associated with reduced radon exposures. In this analysis, the data in Table 3-6
were used to estimate the numbers of fatal cancers of each organ system associated with
inhalation and ingestion pathway from the risk model described in Section 3.1. (These
proportions, by the nature of the risk model that is used, stay constant for all radon levels.)
Subsequently, the total number of cancers of each organ system was estimated. This is necessary
because the output of the risk model is fatal cancers, and the cost of illness and willingness to pay
for non-fatal cancers are only applied to individuals who survive the disease. The total number
of cancers per year of exposure, and the number of non-fatal cancers were estimated from the
fatal cancer numbers using the mortality data in Table 6-1. Thus, for example, a benefit of 100
cases of fatal lung cancer avoided implies approximately 105 total lung cancers avoided, five of
which are non-fatal. This calculation omits rounding error, and the total number of cases is equal
to the fatal cases divided by the mortality rate.
Fatal and non-fatal population cancer risks under baseline conditions were estimated first.
Then, the residual cancer risks were estimated for each of the radon levels. Consistent with the
assumptions made in the cost analysis, residual water radon levels were calculated using a similar
range of technology efficiencies. Radon levels were assumed to be reduced below baseline levels
by either 50, 80, or 99 percent, using the least stringent reduction which could comply with the
radon level under evaluation. Benefits took the form of the reductions in the numbers of fatal
and non-fatal cancers associated with each final level compared to the baseline risks. Table 10-1
shows both the fatal and non-fatal cancers associated with each radon level.
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6.2.2 Value of Statistical Life for Fatal Cancers A voided
As one measure of potential benefits, this analysis assigns the monetary value of a
statistical life (VSL) saved to each fatal cancer avoided. The estimation of the value of a
statistical life involves inferring individuals' implicit tradeoffs between small changes in
mortality risk and monetary compensation (US EPA 1999B). A central tendency value of $5.8
million (1997$) is used in the monetary benefits calculations. This figure is determined from the
value of statistical life (VSL) estimates from 26 studies reviewed in EPA's recent guidance on
benefits assessment (US EPA 1999B) which has been reviewed by EPA's SAB and the Office of
Management and Budget (OMB). It is important to recognize the limitations of existing VSL
estimates and to consider whether factors such as differences in the demographic characteristics
of the populations and differences in the nature of the risks being valued have a significant
impact on the value of mortality risk reduction benefits. As noted above, no separate medical
care or lost-time costs are included in the benefits estimate for fatal cancers, because it is
assumed that these costs are captured in the VSL for fatal cancers.
6.2.3 Costs of Illness and Lost Time for Non-Fatal Cancers \
Two important elements in the estimation of the economic impacts of reduced cancer
risks for non-fatal cancers are the reductions in medical care costs and the costs of lost time. The
costs of medical care represent a net loss of resources to society (not considering the economic
hardship on the cancer patient and family). The cost of lost time represents the value of activities
that the individual must abandon (e.g., productive employment or leisure) as a result of radon-
induced cancer. Together, these two elements are often referred .to as the costs of illness (COI).
Medical care and lost-time costs have been estimated for lung and stomach cancers,
which are the two most common types of tumors associated with radon exposures, and which
account for 99 percent of the total radon-associated cancers. Table 6-2 summarizes the Agency's
latest medical care and lost-time cost estimates for lung cancer (US EPA 1999B, 1998C).
Medical care costs have been estimated from survey data for ten years after initial diagnosis of
patients with either lung or stomach cancer. The medical costs in the first year correspond to the
costs of initial treatment, while medical costs in subsequent years correspond to the average
medical costs associated with monitoring and treatment of recurrences among individuals who
survive to that year. These out-year costs are weighted by the proportion of patients surviving to
the given year. ;
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Table 6-2. Estimated Medical Care and Lost-Time Costs Per Case for
Survivors of Lung Cancer
Year after Diagnosis II Medical Care Costs
(Undiscounted 1997
dollars)1
1
2
3
4
5
6
7
8
9
10
Discounted Present Value
at 7 Percent
Total Discounted Value
f! 997 dollar^
34,677
9,936
9,383
8,969
8,604
8,262
7,934
7,609
7,287
6,974
85,225
$108,287
Cost of Lost Leisure
(Undiscounted 1997
dollars)2
9.886
0
0
0
0
0
0
0
0
0
9,390
Cost of Lost
Productive Time
(Undiscounted 1997
dollars)2
14,393
0
0
0
0
0
0
0
0
0
13,671
I. Medical care cost estimates derived from US EPA 1998B.
2. Lost productive and leisure hours estimates from US EPA 1998B; value of productive time estimated at
S12.47/hr, value of leisure hour estimated at S9.64/hour (from US EPA 1998J).
The lost time due to the radon-induced tumors is assumed to be concentrated in the first
year after diagnosis. This is why the out-year estimates for the costs of lost time in Table 6-2 are
all zero. The dollar costs of lost time given in the table are derived by assigning values lost
productive (work) and leisure (non-productive) hours. The costs given in the top row of Table
6-2 correspond to 776 lost productive hours and 1,493 lost leisure hours per patient. The
estimates of lost productive hours are relatively low for lung cancer primarily because the
average age at diagnosis is advanced (fewer than 34 percent^ lung cancer patients are diagnosed
before age 65).
Using a discount rate of seven percent, the estimated discounted present value in 1997
dollars of combined medical care and lost-time costs for a lung cancer survivor is approximately
$108,000. The estimated value varies with different discount rates. Using a discount rate of
three percent, combined costs are $ 121,600.
Table 6-3 summarizes the estimation of medical and lost-time costs for survivors of
stomach cancer. The combined discounted costs for stomach cancer are similar to those for lung
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cancer, but slightly higher. At a seven percent discount rate, combined discounted costs for
stomach cancer are approximately $114,000 (1997$). At three percent, they are about $126,300
(1997$). ;
Table 6-3. Estimated Medical Care and Lost-Time Costs Per Case
for Survivors of Stomach Cancer
Year after Diagnosis
1
9
->
4
5
6
7
8
9
10
Discounted Present
Value at 7 Percent
Total Discounted Value
Medical Care Costs
(Undiscounted 1997
$37.507.28
$9,328.23
$8,749.24
$8,265.39
$7,829.62
$7,423.51
$7,035.81
$6,663.46
$6,300.32
$5,946.38
$82,997.35
$113,987
Cost of Lost Leisure
(Undiscounted 1997
Holland
$19,337.84
0
0 :
0
0
0
0 :
0 i
0
0
18,368
Time (Undiscounted
1Q97 dollars^
13,288
0
0
0
0
0
0
0
0
0
12,621
Notes: i
1. Medical care cost estimates derived from US EPA 1998C. '
2. Lost productive and leisure hours estimates from US EPA 1998C; value of productive time estimated at
$ 12.47/hr, value of leisure hour estimated at $9.64/hour (from US EPA 1998J).
6.2.4 Willingness to Pay to A void Non-Fatal Cancers
As was the case for fatal cancers, willingness to pay (WTP) measures of the values of
avoiding serious non-fatal illness have also been developed. These WTP measures were .
developed because the cost of illness estimates may be seen as'understating total willingness to
pay to avoid non-fatal cancers. The main reason that the cost of illness understates total WTP is
the failure to account for many effects of disease. For example, it ignores pain and suffering,
defensive expenditures, lost leisure time, and any potential altruistic benefits (US EPA 1999B).
Recently, EPA applied one such study to evaluate the benefits of avoiding non-fatal cancers in
the Regulatory Impact Analysis for the Stage I Disinfectants and Disinfection By-Products Rule
(US EPA 1998M). That study estimated a range of WTP to avoid chronic bronchitis ranging
from $168,600 to $1,050,000 with a central tendency (mean) estimate of $536,000 (Viscusi et al.
1991). In the benefits assessment, EPA uses the central tendency measure as a surrogate for the
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cost of avoiding non-fatal cancers and an alternative to the cost of illness measures discussed
above.
7. COST ANALYSIS OF COMPLIANCE WITH AN MCL
This section estimates the total national costs of complying with the radon rule if all
States and systems were to comply with an MCL of 300 pCi/1. This section also describes how
the costs and economic impacts of reductions in radon exposures were estimated. The cost
analysis in this section is based upon the assumption that 100% of systems will comply with the
MCL. This assumption may overestimate actual costs because the preferred technology for small
systems is the AMCL and MMM program. The modified analysis is shown in Section 9 of this
RIA and shows the costs and benefits for various percentages of systems complying with the
AMCL and MMM approach. Below, the most commonly used and cost-effective technologies
for mitigating radon are described, along with the degree of radon removal that can be achieved.
Costs of achieving specified radon removal levels for specific flow rates are discussed, along
with the need for pre-and post-treatment technologies. The methods used to estimate treatment
costs for single systems and aggregate national costs are explained, and the approach for
translating the costs into economic impacts on affected entities is also described.
7.1 Total National Costs of Compliance
Tables 7-1 summarizes the estimates of total national costs of compliance with the radon
rule assuming 100% compliance with an MCL of 300 pCi/1. The table is divided into two major
groupings; the first grouping displays the estimated costs to systems and the second grouping
displays the estimated costs to States.
7.1.1 How Cost Estimates Were Developed
Cost estimates presented in this chapter are based on available data, assumptions, and
decisions developed by EPA in consultation with stakeholders and water industry experts. This
chapter describes, in detail, how the costs to individual systems were estimated for this proposed
rulemaking.
State costs, presented in Table 7-1, were developed as part of the analyses to comply with
the Unfunded Mandates Reform Act (UMRA) and also the Paperwork Reduction Act (PRA).
Additional information on State costs is provided in Section 8 of this document and also in the
preamble to the proposed radon rule.
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Table 7-1 Summary of Estimated Water Mitigation Costs Under the Proposed Radon
Rule (S Millions, 1997)'
10 Percent
Cost of
Capital
7 Percent Cost
3 Percent Cost
Costs to Water Systems
Total Capital Costs (20 Years)
Annual Costs
Annualized Capital
\nnual O&M
Total Annual Treatment
Monitoring Costs
Recordkeeping and Reporting
Costs2
Total Annual Costs to Water
Costs to States
Administration of Water
Programs
Total Annual State Costs
Total Annual Costs of
Compliance4 ======i
1. Assumes no MMM program implementation costs (e.g.. all systems comply with 300 pCi/l).
2 Figure represents averaae annual burden over 20 years.
3" Costs include treatment, monitoring, O&M. recordkeeping. and reporting costs to water systems.
4. Totals Save been rounded. Costs include treatment, monitoring. O&M. recordkeepmg. reportmg, and State costs for
administration of water programs. i
7.1.2 Benefit-Cost Determination
I
Section 1412 (4)(C) of the SDWA states that "at the time the Administrator proposes a
national primary drinking water regulation under this paragraph, the Administrator shall publish
a determination as to whether the benefits of the maximum contaminant level justify, or do not
justify, the costs based on the analysis conducted under paragraph (3)(C)". The analysis referred
to in paraoraph (3)(C) of the SDWA is the Health Risk Reduction and Cost Analysis (HRRCA).
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EPA published the HRRCA for public comment in the Federal Register on February 26, 1999,
six months prior to proposal of the radon rule, and has revised this analysis as part of the RIA.
The determination as to whether the benefits justify the costs is based solely on the cost
and benefit estimates for water systems which were calculated in the February 1999 HRRCA and
revised as part of this RIA. Costs to States are calculated as part of the UMRA and PRA and are
shown in Table 7-1 and in Section 8. The total national costs of compliance with the radon rule
consist of both costs to water systems and to States and are shown at the bottom of Table 7-1.
7.2 Drinking Water Treatment Technologies and Costs
The two most commonly employed methods for removing radon from drinking water
supplies are aeration and granular activated carbon (GAC) absorption. These treatment
approaches can be technically feasible and cost-effective over a wide range of removal
efficiencies and flow rates. In addition to the radon treatment technologies themselves, specific
pre- or post-treatment technologies may also be required. When influent iron and manganese
levels are above certain levels, pre-treatment may be required to remove or sequester these metals
and avoid fouling the radon removal equipment. Also, aeration and GAC absorption may
introduce possible infectious particulates into the treated water. Thus, disinfection is generally
required as a post-treatment when radon reduction technologies are installed.
When only low removal efficiency is required, and sufficient capacity is available, simple
storage may in some cases be sufficient to reduce radon levels in water below specified radon
levels. Radon levels rapidly decrease through natural radioactive decay, and if storage is in
contact with air, through volatilization. Therefore, storage has also been included in the cost
analysis.
In some cases, water systems will choose to seek other sources of water rather than
employ expensive treatment technologies. Systems may choose a number of strategies, such as
shutting down sources with high radon levels and pumping more from sources with low levels, or
converting from ground water to surface water sources. In the cost analysis, however, it has been
assumed that such options will not be available to most systems, and they will need to obtain
water from other systems. This option is referred to as "regionalization" in the following
discussions.
i
These general families of technologies, along with the specific variants used in the cost
analysis, are described in the following sections.
7.2.1 Aeration
Because of radon's volatility, when water containing radon comes into contact with air,
the radon rapidly diffuses into the gas phase. Several aeration technologies are available. As
will be discussed in more detail below, the specific technology adopted in response to the rule
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will depend on the svstem's influent radon level size, and the degree of radon removal that is
required The following common aeration technologies have been mcluded in this analysis.
Other aeration technologies are available (spray aeration, tray aeration, etc.) that can potentially
be used by water systems to remove radon. These technologies have not been mcluded in the
analysis either because they have technical characteristics that limit their use in public water
systems, or because their removal efficiencies are lower, and/or their unit costs are higher than
the three aeration technologies included in the analysis. . ; -
Packed Tower Aeration (PTAX During PTA treatment,'water flows downward by gravity
and air is forced upward through a packing material that is designed to promote intimate air-
water contact The untreated water is usually distributed on the top of the packing with sprays or
distribution travs and the air is blown up a column by forced or induced draft. This design results
in continuous and thorough contact of the liquid with air (US EPA 1998O). In terms of radon
removal PTA is the most effective aeration technology. Radon removal efficiencies of up to
99 9 percent are technically feasible and not prohibitively expensive for most applications. In
this analysis two different PTA treatments are used to estimate radon removal cost. The costs
are dependant on the degree of reduction required to achieve compliance with the allowable
radon level. The first design is capable of reducing radon levels by 80 percent; the second and
more costly version reduces radon in drinking water by 99 percent.
Diffused Bubble Aeration (PAX Aeration is accomplished in the diffused-air type
equipment by injecting bubbles of air into the water by means of submerged diffusers or porous
plates The untreated water enters the top of the basin and exits from the bottom having been
treated while the fresh air is blown from the bottom and is exhausted from the top (US EPA
1998O) Diffused bubble aeration can achieve radon removal efficiencies greater than 90
percent. In this analysis, a DA system with a removal efficiency of 80 percent is used as the
basis for estimating compliance costs. i
Multiple Staoe Rubble Aeration fMSBA). MSB A is a variant of DA developed for small
to medium water supply systems (US EPA 1998O).- MSB A units consist of shallow partitioned
trays Water passes through multiple stages of bubble aeration of relatively shallow depth. In
this analysis, an MSBA radon removal efficiency of 80 percent is assumed.
All of the aeration technologies discussed above are assumed to be "central" treatments in
the cost analysis. That is, a single large installation is used to treat water from a given source,
prior to the water entering the distribution system to serve many users. It is also technically
feasible to apply some of these technologies at the point, of entry (e.g. just before water from the
distribution system enters the household where it is to be used). However, most aeration
technologies are only cost-effective at minimum flows far above that corresponding to. the water
usage rate of a typical household, and thus point-of-entry application would not likely be selected
as the treatment of choice.
Also, in all of the aeration systems just discussed, the radon removed from water is
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released to ambient (outdoor) air. In this analysis, it has been assumed that the air released from
aeration systems will not itself require treatment, result in appreciable risks to public health, or
result in increased permitting costs for water systems. For the 1991 proposed rule, EPA
conducted analyses of radon emissions and potential risks associated with radon and its progeny
as they disperse from an aeration facility (US EPA 1988, 1989). In summary, these analyses
concluded that the annual risk of fatal cancer from radon and its progeny in off-gas emissions
was 2700 times smaller (108 cases/0.04 cases) than the annual risk of fatal cancer from radon and
its progeny from tap water after all ground water systems were at or below the 1991 target level
of 300 pCi/L. Using the occurrence estimates at that time, the off-gas risk was estimated to be
4800 times smaller (192 cases/0.04 cases) than the radon in tap water risk if no water mitigation
was done (US EPA 1994C). The EPA's SAB reviewed the Agency's report and concluded that:
(1) while the uncertainty analysis could be upgraded to lend greater scientific credibility, the
results of modeling would not likely change, i.e., the risk posed by release of radon through
treatment would be less than that posed by drinking untreated water; and (2) it is likely that the
conservative assumptions adopted by EPA in its air emissions modeling resulted in overestimates
ofrisk(USEPA1994C).
7.2.2 Granular Activated Carbon (GA C)
The second major category of radon removal technology is treatment with granular
activated carbon. GAC adsorption removes contaminants from water by the attraction and
accumulation of the contaminant on the surface of carbon. The amount of surface area available
for adsorption to occur is of primary importance, while other chemical and electrochemical
forces are of secondary significance. Therefore, high surface area is an important factor in the
adsorption process (US EPA 1998O). GAC systems are commonly used in water supplies to
remove pesticides or other low-volatility organic chemicals that cannot be removed by aeration.
Radon can also be captured by GAC filtration, but the amounts of carbon and the contact times
needed to produce a high degree of radon removal are generally much greater than those required
to remove common organic contaminants. For most system sizes and design configurations
evaluated in this study, aeration can achieve the same degree of radon reduction at lower cost
than GAC. However, in the cost analysis for the radon rule, it has been assumed that a small
minority of systems will nonetheless choose GAC technology over aeration alternatives, due to
system-specific needs (e.g., land availability). Also, POE GAC (see below) may be cost-
effective for systems serving only a few households. Depending on the specific design and
operating characteristics, GAC can remove up to 99.9 percent of influent radon, but high removal
efficiencies require large amounts of carbon and long contact times.
Two types of GAC systems have been evaluated: Central GAC and Point of Entry GAC
(POE GAC). Central GAC refers to a design configuration in which the activated carbon
treatment takes place at a central treatment facility, prior to entry into the distribution system.
GAC may be combined with other treatments and may be used to remove contaminants other
than radon in large, centralized facilities. In this analysis, costs are estimated for central GAC
systems with removal rates of 50, 80, and 99 percent. POE GAC generally refers to small to
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medium-sized carbon filtration units placed in the water distribution system just before use
oTcursTe^ before water enters a residence from the distribution, system ) System maintenance
invoWes periodic replacement of the filter units. As noted previously, POE GAC may be the
most cost-effective treatment for very small systems serving few. households. Costs are
estimated for POE GAC with removal rates of 99%.
7.2.3 Storage
Another technology that may be practical when only relatively small reductions in radon
levels are needed is the storage of water for a period of time necessary for radioactive decay and
volamizatL to reduce radon to acceptable levels. Depending on the configuration of the vessel,
Ito7aL for ?4 to 48 hours may be sufficient to reduce radon levels by DO percent or more. The
mode of r moval is a combination of radon decay and transfer of the radon from the water to the
forage taThead space, which is refreshed through ventilation (US EPA, 1998D It has been
aSumed Tat a proportion of the smallest CWSs (serving 500 people or fewer) with relatively
low influent radon levels and sufficient storage capacity may choose storage as the preferred
radon treatment technology. In estimating costs for the storage option, it is assumed that Ae
entire capital and O&M costs of the storage system is attributable to the need to reduce radon
Lv Is In fact, the majority of CWSs choosing storage are likely to already have at least some
storage capacitv available (ten percent of small systems have atmospheric storage in place (US
EPA 1997A)) 'These systems may be able to add ventilation and/or other mechanisms to
fncfease air/water contact with a small capital investment, which supports the conclusion that the
present assumption of no storage in place is a conservative assumption.
7.2.4 Regionalization
The last technology whose costs are included in the HRRCA is regionalization. In this
analysis reoionalization is defined as the construction of new mains to the nearest system with
wafer £low the required radon level. This cost is estimated to be $280,000 per system 1997$)
The cost of actually purchasing water is not included in regionalization costs, for several reasons.
In the first case, regionalization may involve the actual consolidation of water systems, and ftus
may be no charge to the system which is "regionalized". In addition, the system which
water to the regionalized system will still incur the same (or nearly the same) costs
for ion treatment as before regionalization and could be expected to pass ^ <£ *
regionalized system. This assumes that the water production cost ($/kgal) for the CWS before it
regionalizes is equal to the unit price ($/kgal) it will pay to the water system from which it
purchases water. In reality, this will over-estimate costs in some cases and under-estimate in
others Including a water purchase price in the cost estimate for regionalization without
coveting U for fhe removal of water production costs would lead to an over-estimate in the costs
of regionalization.
7.2.5 Costs of Achieving Radon Removal Efficiencies
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The amount of radon that the various technologies can remove from water varies
according to their specific design and operating characteristics. At the most costly extreme, both
aeration and GAG technologies can remove 99 percent or more of the radon in water. Less costly
alternative designs remove less radon. In this analysis, one or more cost estimates have been
developed for the technologies discussed above, corresponding to one or more radon removal
levels. Approximate cost ranges for achieving specified radon reduction efficiencies using the
various technologies are shown in Table 7-2. These costs are estimated based on flow rates for a
single installation, which may treat water for an entire system or from a single source. For the
aeration and GAG technologies, costs have also been derived for combined radon removal and
post-treatment technologies, as discussed below. The basis for the derivation of these cost
estimates is described in more detail in Section 7.5.
i I
! '
I i
The procedures used to decide what proportion of CWSs will adopt the various radon
removal technologies is described in more detail in Section 7.6. In general, however, the large
majority of the systems are assumed to select the least-cost technology required to achieve a
target radon level. Other systems, for reasons of technical feasibility, may need to choose more
costly treatment technologies.
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7.2.6 Pre-Treatment to Reduce Iron and Manganese Levels
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Pre-treatment technologies may also need to be part of radon reduction systems. Aeration
and GAG technologies can be fouled by high concentrations of iron and manganese (Fe/Mn).
EPA believes that Fe/Mn concentrations greater than 0.3 mg/1 would generally require
pretreatment to protect aeration/GAC systems from fouling. However, since this level is near to
the secondary MCL. it is believed that essentially all systems with iron and manganese levels
above 0.3 are likely to already be treating to remove or sequester these metals. Therefore, costs of
adding Fe/Mn treatment to radon removal systems are not included in the HRRCA. Preliminary
EPA estimates suggest that inclusion of Fe/Mn treatment costs will not significantly effect overall
cost estimates for radon removal. More detailed analysis will be presented when the proposed
NPDWR is published.
I '
7.2.7 Post-Treatment—Disinfection
. i
In addition to pre-treatment requirements, the installation of some radon reduction
technologies may also require post-treatment, primarily to reduce microbial contamination. Both
aeration and GAG treatment may introduce potentially infectious particulate contamination, which
must be addressed before the water can enter the distribution system. The treatment of water for
other contaminants may also introduce microbial contamination. This is one reason why the
majority of systems already use disinfection technologies. As discussed in Section 5.2, a
substantial proportion of ground water systems (ranging from 50 percent in the smallest size
category, to about 68 percent of the largest systems) already disinfect. Costs of disinfection are
only attributed to the radon rule only for that proportion of systems not already having disinfection
systems in place. For systems that do not already disinfect, chlorination is assumed to be the
treatment of choice. Alternative technologies are available, for example UV disinfection, but
chlorination is widely used in all size classes of water supply systems, and the chlorination is
considered to provide a reasonable basis for estimating disinfection costs.
7.3 Monitoring Costs
While not strictly speaking a water treatment technology, ground water monitoring will
play an important role in any strategy to reduce radon exposures. Therefore, monitoring costs
have been included as an element in the cost analysis. For the purpose of developing national cost
estimates, it has been assumed that all systems will have to conduct initial quarterly monitoring of
all sources, and continue to conduct radon monitoring and analysis indefinitely after the rule is
implemented. This is a conservative assumption (likely to overstate monitoring costs) because in
reality a large proportion of systems with radon levels below the MCL will probably be allowed to
monitor less frequently after the initial monitoring period.
Monitoring costs are simply the unit costs of radon analyses times the number of samples
analyzed. The number of intake sites per system is estimated from SDWIS data, as discussed in
September, 1999 - Draft Document
-74-
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Section 7.8. The cost of analyzing each sample is estimated to be between $40 and $75, with a
representative cost of $50 per sample used for the national cost estimate (US EPA 1998K).
7.4 Cost of Technologies as a Function of Flow Rates and Radon Removal Efficiency
EPA has developed a set of cost curves that describe the relationships between the capital
and operating and maintenance costs of the various treatment technologies, flow rates, and the
degree of radon removal that is required (US EPA 1998A, 1998O). Cost curves were developed
using the most recent available data and standard cost estimation methodologies. Separate
functions for capital and operation and maintenance (O&M) costs have been developed for each
technology and radon removal rate. For all of the technologies.except regionalization, both the
capital and O&M cost curves are functions of flow rates. Capital costs are estimated as a function
of the design flow (DF) of the technology. The DF for a technology is equal to a technology's
maximum flow capacity, or the largest amount of water that can be processed per unit time. The
DF is typically two to three times greater than the average amount of water treated by a given
system. O&M costs are functions of the average flow (AF) through the system. Labor, treatment
chemicals and materials, periodic structure maintenance, and water stewardship expenses are
estimated based on daily average flows. :
EPA recognizes that the costs of the radon treatment technologies can vary with the
different physicafcharacteristics of systems, even within the same size category and for similar
average and design flows. To evaluate the relative costs of the various MCL and technology
options, costs are developed using EPA's "central tendency" cost curves for the various
technologies These curves are intended to estimate the average cost, across all systems, of the
various technologies. The cost curves developed by OGWDW for the various radon removal
technologies are provided in Appendix B.
7.5 Choice of Treatment Responses
The Agency has developed a set of assumptions regarding the choices that CWSs will
make in deciding how to mitigate water radon levels to meet specific exposure reduction ^
requirements. These assumptions have been developed taking into account the expected influent
radon levels, the degree of radon removal needed to reach specified levels, the types of
technologies that would be technically feasible and cost-effective for systems of a given size, and
the distribution of pre-existing technologies shown in Table 5-4. Generally, it is assumed that a
system will choose the least-cost alternative technology to achieve a given radon level. For
example, to achieve a radon level of 100 pCi/1, all systems with average influent levels below 100
would not need to mitigate, systems with influent radon levels between 100 and 200 pCi/1 would
need to employ technologies that achieve 50 percent reduction, systems with influent levels
between ?00 and 500 pCi/1 would employ technologies capable of 80 percent radon removal, and
systems with influent radon above 500 pCi would employ technologies with removal efficiencies
of 99 percent. In actuality, removal efficiencies would be more variable; e.g., a removal
efficiency of 90 percent, rather than 99 percent, could be employed for radon levels between 500
September, 1999- Draft Document -75-
-------
and 1,000 pCi/1. However, this cost analysis has been limited to three removal efficiencies to
simplify the analysis. EPA does not believe that this has introduced any significant bias into the
assessment.
Table 7-3 presents the most likely proportions of systems of given sizes that are expected
to choose specified radon reduction technologies for given degrees of radon removal. Most
systems in most size classes are assumed to choose aeration as the preferred radon reduction
technology with or without disinfection, depending on the proportion of systems in that size
stratum already disinfecting. This is because some form of aeration is generally the most cost-
effective option for a given degree of radon reduction. For small systems and low required
removal efficiencies, multistage fixed-bed (MSBA) and diffused bubble aeration (DA) tend to be
the most cost-effective. For large systems and high removal efficiencies, packed tower aeration
(PTA) is the only feasible aeration technology.
Small proportions of the smallest system size categories (less than 5 percent in all cases)
are assumed to choose central GAC with or without disinfection. A few percent of the smallest
systems are also assumed to choose POE GAC. Storage is assumed to be a viable option for two
percent of small systems where radon reduction of 50 percent or less is required, and
regionalization is assumed to be feasible for one percent of the smallest systems' EPA has
assumed in this HRRCA that no systems would choose spray aeration or alternative source
technologies. It is believed that these technologies would be chosen only rarely and their
omission has not biased the compliance cost estimates. This issue will be addressed in more
detail in the proposed NPD WR. As was the case for the mitigation cost curves, these proportions
constitute EPA's best estimate of system responses to specific radon regulatory options
September, 1999 - Draft Document .75.
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7.6 Cost Estimation
7.6.1 Site and System Costs
The costs of reducing radon in ground water to specific radon levels was calculated using
the cost curves discussed in Section 7.4 and the matrix of treatment options presented in Section
7.5. For each radon level and system size stratum, the number of systems required to reduce
radon levels by up to 50 percent. 80 percent and 99 percent were calculated. Then, the cost curves
for the distributions of technologies dictated by the treatment matrix were applied to the
appropriate proportions of the systems. Capital and O&M costs were then calculated for each
system, based on typical estimated design and average flow rates. These flow rates were
calculated on spreadsheets using equations from EPA's Baseline Handbook (US EPA 1999A).
The equations and parameter values relating system size to flow rates are presented in Appendix
The distributions of influent radon levels in the various system size categories were
calculated using the results of EPA's updated radon occurrence analysis, as discussed in Section
5.2. The proportion of sources and systems above radon levels were calculated based on the
estimated lognormal distributions of groundwater radon levels, and are not actual counts of
systems or sources.
Capital and O&M costs were estimated separately for each "site" (a separate water source,
usually a well) within systems. Where systems obtained water from only one site, costs are
calculated by applying the entire system flow rate to the appropriate cost curves. Where systems
consisted of more than one site, the total system flow rate was divided by the number of sites,
capital and O&M costs were then calculated for the resulting flow rate, and the total system cost
was obtained by multiplying this result by the number of sites in the system. This approach
provides conservative cost estimates, because it assumes that separate treatment systems would be
built at each site. This approach also obscures some of the effects of variability in system sizes on
costs, because each system in a given size category is assumed to have the same flow rate. The
number of sources per system that were used in the analysis are summarized in Table 5-2.
In addition to the costs of radon treatment and disinfection, monitoring costs were also
calculated for each system. As noted previously, the average cost of monitoring was estimated to
be $50 per sample, and it was assumed that each site in a system would need to be monitored
quarterly. Monitoring costs were added as an ongoing cost stream to the O&M costs.
With the exception of monitoring costs, all cost estimation input data, discussed above,
were included in the quantitative evaluation of cost variability. For purposes of comparing radon
regulatory alternatives, central tendency estimates were used. In the variability analysis,
distributions of the cost inputs reflecting a reasonably expected degree of variability were used.
September, 1999 - Draft Document .yg.
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7.6.2
Aggregate National Costs
The costs of reducing radon levels to meet different potential regulatory MCL alternatives
were estimated by summing the costs for the individual sites and systems in each size category
and influent range. Separate totals were compiled for capital, O&M, and monitoring costs.
Capital costs were annualized (over 20 years at a seven percent discount rate) and added to the
annual O&M costs to provide single aggregate estimates of national costs for each radon level.
This approach implicitly assumes that treatment devices have useful lives that are identical to the
period of financing. In reality, the useful life and period of financing are not necessarily the same.
The aggregate cost estimates for 100% compliance with the MCI are presented in Section 10. As
will be discussed in more detail below, separate cost estimates were developed for
implementation options involving MMM programs and are presented in Section 9. Summary
outputs of the spreadsheet models used to estimate costs are provided in Appendix D.
7.6.3 Costs to Community Water Supply Systems
As noted above, costs were estimated separately for public and private ground water
systems. Costs per system were calculated by dividing total costs for a given size category of
public or private system by the total number of systems needing to mitigate radon. The results of
these assessments are presented in Section 10.5. :
7.6.4 Costs to Consumers/Households
Costs to households have also been calculated for public and private ground water
systems. Costs are calculated by multiplying the average annual treatment costs per thousand
gallons by the estimated average household consumption (83,000 gal/year). This approach
assumes that all water systems pass incremental costs attributable to the radon rule on to system's
residential customers. Average household costs are calculated separately for public and private
community water systems across various system-size categories. Per household costs are then
compared to median household income data (US EPA 1998H) within the same system size
categories. These impacts are discussed in Section 10.6.
7.6.5 Mixed Systems
Current regulations require all systems that use any amount of surface water as a source be
categorized as surface water systems. This classification applies even if the majority of water in a
system is from a ground water source. Therefore, SDWIS does not provide the Agency with
information to identify how many mixed systems exist. This information would help the Agency
to better understand regulatory impacts.
EPA is investigating ways to identify how many mixed systems exist and how many mix
their around and surface water at the same entry point or at separate entry points within the same
distribution system. For example, a system may have several plants/entry points that feed the
September, 1999 -Draft Document
-79-
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same distribution system. One of these entry points may mix and treat surface water with ground
water prior to its entry into the distribution system. Another entry point might use ground water
exclusively for its source while a different entry point would use surface water exclusively.
However, all three entry points would supply the same system classified in SDWIS as surface
water.
One method EPA could use to address this issue would be to analyze CWSS data then
extrapolate this information to SDWIS to obtain a national estimate of mixed systems. CWSS
data, from approximately 1,900 systems, details sources of supply at the level of the entry point to
the distribution system and further subdivides flow by source type. The Agency is considering
this national estimate of mixed systems to regroup surface water systems for certain impact
analyses when regulations only impact one type of source. For example, surface water systems
that get more than fifty percent of their flow from ground water would be counted as a ground
water system in the regulatory impact analysis for this rule. The Agency is requesting comment
on this methodology and its applicability for use in regulatory impact analysis in the preamble for
the proposed rule.
7.7 Application of Radon Related Costs to Other Rules
i J i
The baseline for the radon rule compliance cost estimates presented in this HRRCA
consists of the pre-existing treatment technology distribution shown in Table 5-4. As the radon
rule is implemented, however, other rules may also require additional systems to install new
technologies (e.g., disinfection). Thus, attributing all costs of increased use of disinfection at
Systems with high radon levels to the radon rule would overstate its cost. At the present time,
EPA has not quantified the potential degree to which the costs of the radon rule may be
overstated.
8. ECONOMIC IMPACT ANALYSIS
8.1 Impacts on Governments and Small Business Units
8.1.1 Unfunded Mandates Reform Act (UMRA)
\
Summary of UMRA Requirements
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
September, 1999 - Draft Document
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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.
Written Statement for Rules with Federal Mandates of $100 Million or More
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,
and 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
and disproportionate budgetary effects; (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 more detailed description of this analysis is
presented in this section.
Authorizing Legislation
This 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; paragraph D of this section establishes a statutory deadline of August 1999
to propose this rule and paragraph E of this section establishes a statutory deadline of August
2000 to promulgate this rule.
8.1.1.1 Cost-Benefit Analysis
.Sections 9 and 10 of this RIA contain a detailed cost-benefit analysis in support of the
Radon Rule. This proposed rule is expected to have a total annualized cost of approximately $121
million with a range of potential impacts from $60.4 million to $407.6 million, depending on how
many States and local PWSs adopt MMM programs and comply with the AMCL. This total
September, 1999 - Draft Document -81-
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annual ized 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 conservatively
assumes 50% of States implement MMM programs with the remaining 50% of States
implementing system-level MMM programs or complying with the MCL. Under Scenario E,
total costs are approximately $60.4 million. A detailed description of these scenarios is shown in
Section 9).
Section 10 of this analysis 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 for the 4,000 pCi/1 level and $362.0 million
for the 300 pCi/1 MCL, assuming all systems comply with the MCL. 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 maximum radon level of 4.000 pCi/1, an estimated 2.9
fatal cancers and 0.2 non-fatal cancers per year are prevented. At a level of 300 pCi/1, 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/1 and implementation of a Multimedia Mitigation (MMM) program would
result in health benefits equal to or greater than those achieved by compliance with the MCL (300
pCi/1).
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 VSL estimate. In addition, if chlorination is added to the process of
treating radon in drinking water via aeration, arsenic pre-oxidation 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 an MMM program.
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 drinking water risk
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mitigation can include costs associated with program management, inspections, and enforcement
activities. EPA estimates the total annual costs of administrative activities to support 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) description of the process for
involving the public in the development of an MMM program plan; (2) establish and include in
their plans quantitative goals to measure the effectiveness of their MMM program for existing
houses with elevated indoor radon levels that will be mitigated by the public and new houses that
will be built radon-resistant by home builders; (3) submit and implement plans for radon
mitigation in existing and new homes; and (4) develop and implement plans for tracking and
reporting the results of the program. The administrative costs will consist of the various activities
necessary to satisfy these criteria. Because EPA does not know the exact 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) select MMM implementation; and (2)
100 percent of States implement an MMM program.
If a State does not develop an MMM program, 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/1 would choose to administer an MMM
program rather than achieve the 300 pCi/1 level though water mitigation. It is assumed that, on
average, water risk mitigation costs will exceed 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 plan. The total costs across all system sizes under
Scenario E for system-level MMM programs is approximately $5 million.
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Availability of Federal Assistance
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)(l)] 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 States to set-up and administer a State MMM
program..
i
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.
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However, expenditure of SIRG will not be permitted to fund strictly water-related activities, such
as testing or monitoring of water by CWSs.
8.1.1.2 Estimates of Future Compliance Costs
To meet the UMRA requirement in section 202, 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 above, accurately characterize future
compliance costs of the proposed rule.
8.1.1.3 Macroeconomic Effects :
UMRA Section 202 requires EPA 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 100% compliance with the MCL, the total annual costs are
approximately $43.1 million for the 4,000 pCi/1 level and about $407.6 million at the 300 pCi/1
level per year (at a 7 percent discount rate) and the costs are not expected to be highly focused on
a particular geographic region or industry sector.
8.1.1.4 Summary of EPA's Consultation with State, Local, and Tribal Governments
and Their Concerns
Under UMRA section 202, EPA is to provide a summary of its consultation with elected
representatives (or their designated authorized employees) of affected State, local, and tribal
governments in this rulemaking. 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 from
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other tribes. EPA also made presentations at tribal meetings in Nevada, Alaska, and California.
The Agency also held two series of three conference calls with state drinking water program and
sta^e radon program representatives. 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). In addition to these consultation, 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 9560). 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 on the
February 26, 1999 notice. Of the 26 comments received concerning the HRRCA, 42% were from
States and 4% were from local governments.
The public docket for the 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 government's concerns. A summary of
State, local, and tribal government concerns on this proposed rulemaking is shown below in the
next 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 attendees representing tribes from across the
country were in attendance. During the conference, EPA conducted two workshops for meeting
participants. The objectives of the workshops were to present an overview of EPA's drinking
water program, solicit comments on key issues of potential interest in upcoming drinking water
regulations, and to solicit advice in identifying an effective consultative process with tribes for the
future.
EPA, in conjunction with the Inter-Tribal Council of Arizona (ITCA), also convened a
tribal consultation meeting on February 24-25, 1999 in Las Vegas, Nevada to discuss ways to
involve tribal representatives, both tribal council members and tribal water utility operators, in the
stakeholder process. Approximately twenty-five representatives from a diverse group of tribes
attended the two-day meeting. Meeting participants included representatives from the following
tribes: Cherokee Nation, Nezperce Tribe, Jicarilla Apache Tribe. Blackfeet Tribe, Seminole Tribe
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of Florida, Hopi Tribe, Cheyenne River Sioux Tribe, Menominee Indian Tribe, Tulalip Tribes,
Mississippi Band of Choctaw Indians, Narragansett Indian Tribe, and Yakima 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. 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. Meeting summaries for EPA's tribal consultations are available in the public docket
for the proposed rulemaking. A summary of tribal government concerns and EPA's response to
their concerns is provided in the next section.
8.1.1.5 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.
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EPA understands the State, local, and tribal government concerns with the above issues.
The Agency believes that the option 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.
i
i i i
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 of the preamble for the proposed rule. EPA has conducted a preliminary analysis on
exposure and risks to NTNCWSs and is soliciting public comment on this preliminary analysis.
EPA has also included an analysis of the benefits and costs to NTNCWSs in Appendix F.
EPA has included the risks to both ever-smokers and never-smokers in the 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 3 of this analysis.
I
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 discussed in Section 8.1.1.1.
8.1.1.6 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, this analysis evaluates radon MCL options ofTOO, 300, 500, 700, 1,000, 2,000, and
4,000 pCi/1.
The RIA also evaluates 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 (NAS) recommendations, the AMCL level that was evaluated is
4,000 pCi/1. For further discussion on the regulatory alternatives considered in the proposed
rulemaking, see Section 4 of this RIA.
EPA believes that the regulatory approaches proposed for radon are the most cost-effective
options that achieve the objectives of the rule and provide the highest degree of public health
protection.
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8.1.1.7 Impacts on Small Governments
In preparation for the proposed Radon Rule, EPA conducted analysis on small government
impacts and 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 the proposed rulemaking.
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, as required by the Small Business Regulatory
Enforcement Fairness Act of 1996. 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.
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8.L2 Indian Tribal Governments
Executive Order 13084, Consultation and Coordination with Indian Tribal Governments,
states that 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.
EPA has concluded that this rule will significantly or uniquely affect communities of
Indian tribal governments because it will impose substantial direct compliance costs on such
communities, and the Federal government will not provide the funds necessary to pay the direct
compliance costs incurred by the tribal governments in complying with this rule.
EPA estimates that there are approximately 500 tribal water systems in the United States
and that all of these tribal water systems may be disproportionately impacted by this rule.
Because these tribal water systems are small systems, EPA anticipates that, by requiring small
systems to comply with the AMCL of 4,000 pCi/1 and implement an MMM program, the financial
burden on small systems, and thus tribal systems, to comply with the radon rule will be
significantly reduced.
In developing this rule, EPA consulted with representatives of tribal governments pursuant
to Executive Order 13084. EPA's consultation, the nature of the governments' concerns, and how
EPA addressed their concerns are described above.in Sections 8.1.1.4 and 8.1.1.5.
! i ' i
8.1.3 Regulatory Flexibility Act (RFA)
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. This proposed rule may have significant economic impact on a
substantial number of small entities and EPA has prepared this 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 below.
8J.3.1 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
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"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.
8.1J.2 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 above requirements. The following is a summary of
the IRFA.
The first and second requirements are discussed in Section II of the Preamble. The third,
fourth, and sixth requirements are summarized as follows. The .fifth requirement is discussed
under Section VIII. A.2 of the Preamble in a subsection addressing potential interactions between
the radon rule and upcoming and existing rules affecting ground water systems.
8.1.3.3 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 8-
1 indicates, water mitigation administration costs for small systems remain the same under any
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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 Section 9.
Table 8-1. Annual Water Mitigation and MMM Program Costs to Small Systems
(SMillions, 1997)
Cost Description
Water Mitigation
Costs'
Total Capital Costs
Total Annual Costs2
Water Mitigation Administration Costs
Multimedia Mitigation Program Costs
Total Small System Costs per Year
100% of States
Adopt MMM
118.5
31.3
5.8
0
37.1
50% of States
Adopt MMM
194.1
43.2
5.8
43.3
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.
8.1.3.4 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 of the
preamble). 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 of the preamble). 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.
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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).
8.1.3.5 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 the 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.
In addition to being summarized here, the public docket for the 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.
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". 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" (US EPA 1994C).
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On May 11, 1998, EPA held a small entity conference call from Washington D.C. 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 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 SB A.
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.
Recommendations and Actions
\ \
The proposed rule 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
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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 ot this
Preamble discusses the MMM program in greater detail. ;
The 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 of the preamble "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 (GAG) 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 (GAG)
treatment may be appropriate as a central or point-of-entry unit treatment technology (See Section
VIII A 3 of the preamble "Centralized GAG and Point-of-entry GAG"); the RIA and the treatment
sections of the preamble describe the components which contribute to the regulatory economic
analysis (See Section VIII.A.2 of the preamble "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 typicd cases (see
Sections VIII A 2 of the preamble "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 ottgas
from aeration towers will not preclude installation of aeration treatment (see Section VIII.A.3 oi
the preamble "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 VIIIA of the preamble "Potential Interactions Between the Radon Rule and
Upcoming and Existing Rules Affecting Ground Water Systems").
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Analytical Methods and Monitoring: The Panel recommended the following- fully
consular the availability and capacity of certified laboratories for radon analysis and consider the
Sin T nng; T f ?Plylng ^ V°CS SampHng meth°d t0 radon to ^uce the need for
anH on , H mg^ -the ^^ of monitorin§ *&* initial determination of compliance
and consider providing waivers from monitoring requirements when a system in not at risk of
exceeding the MCL; and develop monitoring requirements that are simple and easy to interpret to
facilitate compliance by small systems. uucipreiro
*va-i KM analytical methods section of the Preamble includes discussion of the
availability and capacity of certified laboratories for radon analysis (see Section VIII C of the
So ^T^ ^Pf0*3: - PraCtiCal Availability ^ *e Methods"); and a clarification that
the radon samphng method is the same as for the volatile organic carbons sampling method (see
Section VllLBl of the preamble "Sampling Collection, Handling and Preserva'tionTlhe wT
and the preamble include more detailed discussion of regulatory costs estimates including the
monitoring costs estimated (see Section VIH.B.2 of the preamble "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 '/2 MCL/AMCL provided tono
sample exceeds the MCL/AMCL (see Section VIII E.4 of the preamble "IncreasedTdecrea ed
monitoring requirements" and Section 141.28(b) of the proposed rule). Section VIII E 5 of the
S£±L Gf^df^r^f 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 VIU E.4 of the preamble "Increased/decreased monitoring reTutmenS
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 frequency. Section VIII.E, Table VIII E 1 of the
preamble also describes monitoring requirements to facilitate interpretation of the requirements.
recommended *at EPA explore options for providing technical
ndnn * '^ COmmunicate the *** ^m radon in drinking water and
indoor air, the rationale supporting the regulation, and actions consumers can take to reduce their
drinHnlf rS' f rambIe,haS been ^^ t0 Clarffy t0 the Public the risks f— radon in
ttnl > - ^ rad°nale — ^ ^ ™~* -ulation (see
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 compliLe
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 tha do no^ s
TT' •"? "^ inf0rmati°n °n th£ risks °f radon -d OP^ for reducing t
health nsk reduction benefits" (as referenced in the SDWA) independent of whether
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homes are actually mitigated or built radon resistant. A detailed discussion of these issues is
included in the Panel report.
8.1.4 Paperwork Reduction Act (PRA)
The information collection requirements in the proposed rule have been submitted for
approval to the Office of Management and Budget (OMB) under the Paperwork Reduction Act
(PRA), 44 U.S.C. 3501 et seq. An Information Collection Request (ICR) document has been
prepared by EPA (OMB control number 1923.01) and a summary of the ICR is shown below.
8.1.4.1 Summary of Information Collection Requirements
Two types of information will be collected under the proposed 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 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. 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
groundwater 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. 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 two 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 EP A-approved MMM program and enforce the AMCL for
radon rather than the MCL. Similarly, information related to system-level MMM programs is
required only of systems that comply with the AMCL rather than the MCL and are in States that
do not have a MMM program in place.
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AMrr I* lSV lnformatlon dlscussed Previously, on compliance with the MCL or
AMCL and on MMM programs, is essential to achieving the radon-related health risk reductions
anticipated by the EPA under the proposed rule. reductions
i
EPA has estimated the burden associated with the specific record keeping and
"
• time' effort' or fmancial reso"rces expended
Th ?T? ' rmtam' retain' °r diSCl°Se °r Pr°vide ^formation to or for a Federal
This includes the time needed to review instructions; develop, acquire install and utilize
technology and systems for the purposes of collecting, validating, and vending nform^n
processing and maintaining information, and disclosing and providing info^Ln aZ the
oe±n8erSHt0 M ^ Withfy PreVi°USly aPpHcable inStrUCtions -d requirement, Strain
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
costs do
d°
EPA has estimated a range of administrative costs for the proposed rule These
" 1 ^8 ^ °r teStin§ ^ mitigating h°USehoIds in the M
amaud C°St ** Iabor for Administrative costs be
programs and the proportions of states that elect to implement state-wide MMM programs These
raros^A Tib;d in detail in section XIILG °f the preamwe *« s^***^ sr
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 ($357 per system) or 267,625 hours, dis Huted
be Jthe^ S12e, " "ST TabIC ^ A" 4°'863 C°mmunity S-undwater systems will
bear these costs under all scenarios evaluated.
,|
In the first three years of the rule, there are no administrative costs to community
groundwater systems for MMM program activities.
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Table 8-2. Administrative Costs to Community Water Systems Associated
With Water Mitigation and System-Level MMM Programs
(Excluding MMM Testing and Mitigation)
System Size
(Customers Served)
VVS (25-100)
VVS (10 1-500)
VS (501-3,300)
S (3,301-10,000)
M(10,001-100K)
L (>100K)
Total For All Systems
Administrative Costs of
Water Mitigation
($ per year)
4,485,485
4,958,735
3,430,387
848,487
491,944
23,579
14,598,617
Administrative Costs
of System-Level MMM
Programs ($ per year)
0
0
0
0
0
0
0
Administrative costs to States for water mitigation-related activities are to be
approximately $3 million per year (Table 8-3) and 119,625 hours, or approximately
$65,400 per year per state and 2,600 hours per year per state. Forty-six states bear these
costs under all scenarios.
Table 8-3 presents the costs if 100 percent of all states were to incur the specific
administrative costs listed. However, no state will bear 100 percent of state-wide MMM program
costs and 100 percent of system-level MMM program costs. These costs will be borne in an
inverse relationship; e.g., 95 percent of the states will bear administrative costs associated with
state-wide MMM programs and 5 percent of states will bear administrative costs associated with
system-level MMM programs.
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Table 8-3. State Administrative Costs for Water
Mitigation and MMM Programs ($ per year)
Water Mitigation
State- Wide MMM Programs
System-Level MMM
Programs
Total State Administrative
Costs
3,009,713
6,346
5,909
3,021,968
nn C°StS 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 elated up to $5,900 per yera and up to 123 hours per year for the first three years of
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
: I
_ Because much of the activity required under the proposed rule occurs in later years this
analysis presents avearge 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 mitigatin*
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. b>'system size as shown in Table 8-4. All 40,863 community groundwater
systems will bear these costs under all scenarios evaluated.
I
Under Scenario A, administrative costs to community groundwater systems for MMM
?S8^,aCtlVltieS ^ 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
sysetms) that develop and file an MMM plan. The costs are distributed across the system
size categories as shown in Table 8-4. Under Scenario E, administrative costs to systems
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are $5.0 million per year or 19,333 hours per year. The per-system cost is the same as
Scenario A, but only five percent of systems (2,042) bear these costs.
Table 8-4. Administrative Costs to Community Water Systems Associated With Water
Mitigation and System-Level MMM Programs (Excluding MMM Testing and Mitigation)
System Size
(Customers Served)
VVS (25-100)
VVS (101-500)
VS (501-3,300)
S (3,301-10,000)
M(10,001-100K)
L (>100K)
Total for All Systems
Administrative
Costs of Water
Mitigation ($ per
year)
2,857,190
2,923,970
2,022,764
500,319
290,080
13,904
8,608,226
Administrative
Costs of System-
Level MMM
Programs Under
Scenario A ($ per
year)
14,978,142
15,328,217
10,603^857
2,622,804
1,520,674
72,886
45,126,581
Administrative
Costs of System-
Level MMM
Programs Under
Scenario E ($ per
year)
1,664,238
1,703,135
1,178,206
291,423
168,964
8,097
5,014,065
Total administrative costs to community water systems (water mitigation plus MMM
programs) range from $11 million per year under Scenario E to $51.2 million under
Scenario A or 165,000 hours under Scenario E to 320,000 hours under Scenario A. The
costs are distributed across the various system sizes as shown in Table 8-5.
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Table 8-5. Total Administrative Costs of Water Mitigation and MMM Programs to
Community Groundwater Systems
System Size (Customers
Served)
VVS(25-100)
VVS (101-500)
VS (501-3,300)
8(3,001-10,000)
M (10,00 1-100,000)
L (100,000)
Total for All Systems
Total Administrative Costs
Under Scenario A
($ per Year)
16,990,791
17,387,906
11,238,829
3,412,697
1,873,106
256,893
51,160,223
Total Administrative Costs
Under Scenario E
(S per Year)
3,676,887
3,762,824
1,813,178
1,081,316
521,396
192,105
11,047,707
Administrative costs to States for water mitigation-related activities are estimated to be
approximately $2.5 million per year (Table 8-6) or approximately $53,900 per year per
state. Total state burden is approximately 100,000 hours per year. Forty-six states bear
these costs under all scenarios.
Table 8-6. State Administrative Costs for Water Mitigation and MMM Programs
($ per year)
Water Mitigation
State- Wide MMM Programs
System-Level MMM
Programs
Total State Administrative
Costs
Scenario A
2,477,299
2,926,691
7,830,995
13,234,985
Scenario E
2,477,299
5,560,713
870,111
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
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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
thecost 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.
8.2 Impacts on Subpopulations
EPA is using risk estimates developed by the National Academy of Sciences (NAS) for its
assessment of the risks from radon in drinking water. The NAS concluded that there is
insufficient scientific information to permit separate cancer risk estimates for subpopulations such
as pregnant women, the elderly, children, and seriously ill persons. The NAS also concluded that
current and former smokers are considerably more sensitive to radon and progeny inhalation
exposures than never-smokers. A complete discussion on the NAS Report findings related to
sensitive subpopulations is provided in Section 3.3, and the findings related to smokers are
discussed in Section 3.8.
8.3 EnvironmentalJustice
Executive Order 12898 "Federal Actions To Address Environmental Justice in Minority
Populations and Low-Income Populations," 59 FR 7629 (February 16, 1994) establishes a Federal
policy for incorporating environmental justice into Federal agency missions by directing agencies
to identify and address disproportionately high and adverse human health or environmental effects
of its programs, policies, and activities on minority and low-income populations. The Agency has
considered environmental justice related issues concerning the potential impacts of the radon rule
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
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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 the proposed rulemaking.
i
Stakeholders have raised concerns that the proposed rule 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, thought 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.
i i
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
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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 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 arid 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.
9. RESULTS: WEIGHING THE COSTS AND BENEFITS OF THE PROPOSED
RULE
This Section presents an analysis of the likely costs and benefits under different
implementation scenarios in which States choose to develop and implement multimedia
mitigation (MMM) programs to comply with the radon NPDW!*.. The analysis presented in this
section reflects the most cost-effective method of achieving the health risk reduction benefits of
complying with the radon rule. As shown in Section 10, strict compliance with an MCL of 300
pCi/1 results in significantly higher compliance costs than the costs associated with the option
chosen for the proposed rule and shown in this section.
9.1 Multimedia Mitigation Programs for Radon Risk Reduction
The SDWA, as amended, provides for development of an Alternative Maximum
Contaminant Level (AMCL), with which public water systems may comply if their state or
system has an EPA-approved MMM program to reduce radon in indoor air. The idea behind the
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AMCL and MMM option is to reduce radon health risks by addressing the most significant
sources of radon exposure, which typically come from indoor air, rather than from drinking water
If a state implements a statewide MMM program to reduce radon risk, it could then allow public
water systems to control water radon levels to the AMCL, rather than the more stringent MCL If
a state does not choose to implement a statewide MMM program, then individual community
water systems may propose a system-level MMM program for state approval. The Agency is
currently developing guidelines for MMM programs, which will be published for public comment
along with the proposed NPDWR for radon.
For the RIA, EPA used a simplified approach to estimating costs of mitigating indoor air
radon risks. A point estimate of the average cost per life saved under the current voluntary radon
mitigation programs served as the basis for estimating the costs of risk reduction under the MMM
options. The Agency has estimated the average screening and mitigation cost per fatal lung
cancer avoided to be approximately $700,000, assuming the current distribution of radon in
indoor air, that all homes would be tested for radon in indoor air, and that all homes at or above
EPA s voluntary action level of 4 pCi/1 would be mitigated. This value was originally derived
based on data gathered in 1991. The same value has been used in the RIA, without adjustment for
inflation, after discussions with personnel from EPA's Office of Radiation and Indoor Air
indicated that screening and mitigation costs have not increased since 1991.
9.2 Implementation Scenarios
1 ! !
EPA evaluated the annual cost of five MMM implementation scenarios that span the range
of participation in MMM programs that might occur when a radon NPDWR is implemented
Each scenario assumes a different proportion of States' will implement the AMCL along with
statewide MMM programs.
Scenario A: 50 percent of States implement statewide MMM programs.
i i
Scenario B: 60 percent of States implement statewide MMM programs.
Scenario C: 70 percent of States implement statewide MMM programs.
Scenario D: 80 percent of States implement statewide MMM programs.
Scenario E: 95 percent of States implement statewide MMM programs.
' It has been assumed that "50 percent of the states" will, on average, mean 50 percent of
systems in the U.S; "60 percent of states" means 60 percent of systems, etc.
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States that do not implement statewide MMM programs instead may review and approve
any system-level MMM programs prepared by community water systems. In these states,
regardless of scenario, 10 percent of systems are assumed to comply with the MCL and 90 percent
of systems are assumed to comply with the AMCL and to implement a system-level MMM
program.
Costs and benefits have been estimated for radon levels of 100, 300, 500, 700, 1000, and
2000, and 4000 pCi/1 in public domestic water supplies, supplemented by State MMM programs
allowing compliance with an AMCL of 4000 pCi/1. Costs and benefits are presented for the
different system sizes. The analysis assumes that the proportions of systems electing system-level
MMM programs is constant across all size categories.
Currently, it is not possible to estimate the actual degree of State participation in MMM
programs, because there is little information at present as to how these programs would be funded
or upon whom the costs would fall. Thus, economic impacts of the MMM programs at the system
and household level have not been calculated.
9.3 Multimedia Mitigation Cost and Benefit Assumptions
9.3.1 Health Benefits
Under baseline assumptions (no control of radon exposure), 168 fatal cancers and 9.7 non-
fatal cancers per year are estimated to occur from radon exposures through community water
systems (see Section 10). At a radon level of 4,000 pCi/1, an estimated 2.9 fatal cancers and 0.2
non-fatal cancers per year are prevented. At the 300 pCi/1 maximum exposure level, 62 fatal and
3.6 non-fatal cancers per year would be prevented. At the lowest radon level evaluated (100
pCi/1), 120 fatal and 7.0 non-fatal cancers per year would be prevented. Statutory language
requires that MMM programs achieve the same degree of risk reduction as would be achieved by
control of radon in water alone. Therefore, it has been assumed that implementation of a radon
AMCL of 4,000 pCi/1, supplemented by a multimedia mitigation program, would generate health
benefits equal or greater to those achieved by the imposition of the more stringent radon level
(300 pCi/1).
EPA has developed monetized estimates of the health benefits associated with the risk
reductions from radon exposures, as discussed in Section 6. Monetized health benefits are
estimated using an estimated value of a statistical life (VSL) applied to each fatal cancer avoided.
For non-fatal cancers, willingness to pay (WTP) data to avoid chronic bronchitis is used as a
surrogate to estimate the WTP to avoid non-fatal lung and stomach cancers. Because most radon-
induced cancers have a high mortality rate, and because the central tendency estimate of the VSL
is greater than the central tendency WTP estimate, monetary benefits are dominated by the value
of fatal cancers prevented.
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EPA has developed national aggregate estimates of the health benefits of radon exposure
reduction. The monetized benefits realized by the 4,000 PCi/l level alone are estimated to be
approximately $17.0 million per year, while the 300 pCi/1 level generates annual monetized health
benefits of $.>62 million. As noted above, the benefits of MMM scenarios which include both an
AMCL and a more stringent MCL are assumed to be equal to that achieved by imposition of the
MCL alone. In calculating benefits of the MMM scenarios it has been assumed that 62 0 cases of
ratal cancer would be avoided as was calculated for the 300 pCi/1 MCL compliance scenario
presented above.
! . |
In addition to quantifiable benefits, EPA has identified several potential non-quantifiable
benefits associated with reducing radon exposures in drinking water. These benefits may include
peace-of-mmd associated with reduction of radon risks that may not be adequately captured in the
VSL estimate. In addition, if chlorination is added to the process of treating radon via aeration
arsenic pre-oxidation 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. This may result in
health benefits or treatment cost reductions over and above the health benefits realized by radon
removal alone. Finally, provision of information to households concerning the risks of radon in
indoor air and available options to reduce exposure is a potential non-quantifiable benefit that
may be attributed to some components of MMM programs. Providing such information may aid
households in making more informed choices about the need for risk reduction given their
specific circumstances and concerns than they would have in the absence of an MMM program
These potential benefits have not been quantified in this analysis.
9.3.2 Radon Mitigation Costs (no MMM Programs)
The estimated total annual cost of mitigating radon in drinking water is $43.1 million for
the 4,000 pCi/1 level and $407.6 million for the 300 pCi/1 levels (see Chapter 10) At both of
these levels, costs of water mitigation alone exceed monetized benefits
9.4
Costs and Benefits of Multimedia Mitigation Program Implementation
EPA has estimated system-level and State-level costs for five scenarios All these
S 3SSUme 10 perC6nt °f community groundwater systems in states without state-wide
MMM programs comply with the MCL, and 90 percent of the systems comply with the AMCL
and implement a system-level MMM program. Table 9-1 summarizes the implementation
assumptions for each scenario.
September, 1999 - Draft Document
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Implementa-
tion Scenario
A
B
D
Table 9-1. Summary of MMM Scenario Assumptions
Proportion of Systems
Mitigating Radon to 300
pCi/1 and Not
Proportion of
States'
Implementing
State-Wide MMM
Programs
50 Percent
60 Percent
70 Percent
80 Percent
Proportion of Systems
Mitigating Radon to 4,000
pCi/1 and Implementing
System-Level MMM
Program
95 Percent
96 Percent
97 Percent
98 Percent
Implementing System-
Level MMM Program
5 Percent
4 Percent
Percent
2 Percent
0.5 Percent
Notes:
1
. It is assumed that 50 percent of states implies, on average, 50 percent of systems nationwide, etc.
9.4.1 System-Level and State Costs
The total annual cost of the water mitigation and MMM, program varies significantly
depending on assumptions regarding the number of states implementing MMM programs. Table
9-2 shows that total annual system-level and state-level costs decrease from $121.1 million to
$60 4 million as the percentage of states implementing statewide MMM programs increases from
50 to 95 percent. System-level costs decrease from $104 million to $47 million as the percentage
of states implementing statewide MMM programs changes from 50 to 95 percent. Costs for
actual mitigation of radon in indoor air rise from $3.9 million to $4.1 million as the percentage of
States implementing MMM programs rises from 50 to 95 percent. Note that these mitigation
costs are relatively flat because all scenarios assume that 95 percent or more of the risk reduction
will be achieved through MMM at either the State or local level. Additional MMM scenario cost
and benefit tables for MCL levels of 100, 500, 700, 1000, 2000, and 4000 pCi/1 are shown in
Appendix E.
9.4.2 Benefit-Cost Ratios and Net Benefits of MMM Scenarios
Table 9-3 presents the ratios of benefits to costs of MMM programs at 300 pCi/1 for each
scenario by system size. The tables in this section, except for the last row in each table, do not
include state level costs, but analyze the benefits and costs at the system level. Benefit-cost ratios
are less than one for the smallest system size category (systems serving less than 500 people), but
greater than one for all larger systems under all four scenarios. For the large systems, benefit-cost
ratios range from 2.6 for systems serving 501-3,300 people under Scenario A to approximately
41 4 for systems serving 10,000 to 100,000 people under Scenario E. Overall benefit-cost ratios
are over one for all five scenarios when State costs are included. This pattern is seen primarily
September, 1999 - Draft Document
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because a larger proportion of smaller systems having influent radon levels exceeding 4000 pCi/1
AMCL. A larger proportion of these systems, therefore, incur water mitigation costs to comply
with the AMCL than is the case for larger systems.
September, 1999 - Draft Document
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tl
System Size
25-100
101-500
501-3300
3301-10,000
10,001 -100,000
>100,000
Total CWS
Water Mitigation
Costs
Table 9-2 (A) Annual System-Level ar
ie Multimedia Mitigation and AMCL Op
Scenario A
45% Implement
System-Level
MMM Program;
5% Mitigate
Water to 300
piC/L MCL; 95%
Mitigate Water to
4000 piC/L AMCL
Scenario B
36% Implement
System-Level
MMM Program;
4% Mitigate
Water to 300
piC/L MCL; 96%
Mitigate Water to
4000 piC/L AMCL
d State-Level Costs Associated with
tion (SMillions/Year) (MCL = 300 pCi/L)
Scenario C
27% Implement
System-Level
MMM Program;
3% Mitigate
Water to 300
piC/L MCL; 97%
Mitigate Water to
4000 piC/L AMCL
Scenario D
18% Implement
System-Level
MMM Program;
2% Mitigate
Water to 300
piC/L MCL; 98%
Mitigate Water to
4000 piC/L AMCL
Scenario E
5% Implement
System-Level
MMM Program;
.5% Mitigate
Water to 300
piC/L MCL;
99.5% Mitigate
Water to 4000
piC/L AMCL
System Costs for Water Mitigation ($ millions/year)
10.2
17.6
9.9
5.5
7.5
2.0
52.7
9.7
16.9
9.2
5.0
6.6
1.7
49.1
9.3
16.3
8.5
4.3
5.6
1.4
45.4
8.8
15.6
7.7
3.9
4.6
1.1
41.8
8.1
14.6
6.7
3.1
3.2
0.7
36.3
Water System Administration Costs ($ millions/year)
System Size
25-100
101-500
501-3300
3301-10,000
10,001 -100,000
>100,000
Total CWS
Administrative
Costs
Total CWS
Water Mitigation
and
Administrative
Scenario A
17.0
17.4
12.0
3.0
1.7
0.1
51.2
104.0
Scenario B
14.0
14.3
9.9
2.5
1.4
0.1
42.1
91.2
Scenario C
11.0
11.3
7.8
1.9
1.1
0.1
33.1
78.5
Scenario D
8.0
8.2
5.7
1.4
0.8
0.0
24.1
Scenario E
3.7
3.8
2.6
0.6
0.4
0.0
11.1
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Table 9-2 (B) State MMM Administrative Costs ($ millions/year)
Scenario A
50% of States
Implement State-
wide MMM
Program; 45% of
CWS Implement
System-Level
MMM Program
Scenario B
60% of States
Implement State-
wide MMM
Program; 35% of
CWS Implement
System-Level
MMM Program
Scenario C
70% of States
Implement State-
wide MMM
Program; 25% of
CWS Implement
System-Level
MMM Program
Scenario D
80% of States
Implement State-
wide MMM
Program; 15% of
CWS Implement
System-Level
MMM Program
Scenario E
95% of States
Implement State-
wide MMM
Program; 5% of
CWS Implement
System-Level
MMM Program
State costs associated with State-wide MMM program administration, reviewing system-level
MMM programs, and reviewing system-level water mitigation requirements are not distributable
across different system sizes.
State
Administration
Costs for Water
Mitigation
State
Administration
Costs for State-
Level MMM
Mitigation
State
Administration
Costs for System-
Level MMM
Vlitigation
Administration
Costs
2.5
2.9
7.8
13.2
2.5
3.5
6.1
12.1
2.5
4.1
4.4
10.9
2.5
4.7
2.6
9.8
2.5
5.6
0.9
8.9
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Table 9-2 (C) MMM Testing and Mitigation Costs (Smillions/year)
CWS MMM
Costs
State MMM
Costs
Total MMM
Costs
TOTAL COSTS
(From Tables
XHI.18A, B,
andC)
Scenario A
1.9
2.1
3.91
121.1
Scenario B
1.5
2.5
3.95
107.3
Scenario C
1.1
2.9
3.99
93.4
Scenario D
0.7
3.3
4.03
79.7
Scenario E
0.2
3.9
4.12
60.4
Table 9T3. Ratio of Benefits and Costs (System-Level) by System Size for Each Scenario
(MCL = 300pCi/I)
System Size
Z5-100
101-500
501-3,300
3,301-10,000
10,001-
100,000
> 100,000
OVERALL
Benefits,
$M
3.5
16.9
58.0
59.2
147.3
76.7
361.6
Scenario A
0.13
0.48
2.59
6.87
15.82
37.16
2.98
Scenario B
0.14
0.53
2.98
7.85
18.35
43.70
3.37
Scenario C
0.17
0.61
3.51
9.16
21.84
53.04
3.87
Scenario D
0.21
0.70
. 4.27
11.0
26.96
67.44
4.54
Scenario E
0.30
0.92
6.23
15.61
41.43
113.68
5.99
Table 9-4 shows the net benefits (benefits minus costs) of the various MMM
implementation scenarios. As would be expected from the benefit-cost ratios in Table 9-3, all the
systems serving more than 500 people realize net positive benefits under all four scenarios. By far
the largest proportion of net benefits are realized by systems serving 10,000 to 100,000 people.
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Table 9-4. Net Benefits by System Size for Each Scenario (SM, 1997) (MCL = 300 pCi/I)
>S-100
101-500
501-3,300
3,30 1-10,000
10,001-
100,000
> 100,000
Overall
16.9
58.0
59.2
147.3
76.7
361.6
Scenario A
(24.3)
(18.7)
35.6
50.6
138.0
74.6
240.5
Scenario B
(20.7)
(14.8)
38.6
51.7
139.3
74.9
254.3
Scenario C
(17.1)
(11.0)
41.5
52.7
140.6
75.3
268.2
Scenario D
(13.5)
(7.1)
44.4
53.8
141.8
75.6
Scenario E
(8.3)
(1.6)
48.7
55.4
143.7
76.0
9.4.3 Household Costs
I
Table 9-5 presents the costs per household for each scenario and system size. Costs per
household decrease significantly with increasing system size across all scenarios. For the largest
systems, costs for the five scenarios range from $0.20 to $0.60 per household per year. For the
smallest systems (serving less than 100 people), costs range from $81.90 to $193.00 per
household per year. Cost per household decrease slightly for all system sizes as the percentage of
states implementing a statewide MMM program increases from 50 to 95 percent.
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Table 9-5. Costs per Household by System Size for Each Scenario (Includes Only System-
Level Costs, $1997 (MCL = 300 pCi/1))
System Size
>5-100
101-500
501-3,300
5,301-10,000
10,001-
100,000
> 100,000
Overall
#of
Households
Served by
Systems >
300 piCl
MCL
144,165
599,171
2,702,014
2,974,655
7,787,850
3,199,008
17,406,863
Scenario A
193.0
59.4
8.3
2.9
1.2
0.6
6.1
Scenario B
168.0
53.0
7.2
2.5
1.0
0.5
5.3
Scenario C
143.1
46.5
6.1
2.2
0.9
0.5
4.6
Scenario D
118.1
40.1
5.0
1.8
0.7
0.4
3.8
Scenario E
81.9
30.8
3.4
1.3
0.5
0.2
2.7
9.4.4 Cost Per Fatal Cancer Avoided
At the system level, the total cost per fatal cancer case avoided ranges from $15.7 to $0.02
million depending on system size and scenario implemented (Table 9-6.) For the smallest
systems (serving less than 100 people) the total costs per life saved varies from $25.1 to $95.6
million. For systems serving 101-500 people, the cost per fatal cancer avoided ranges from $5.8
to $6.8 million. For all system size categories serving more than 500 people, the cost per fatal
cancer avoided is $1.1 million or less. Costs per fatal cancer avoided are similar for the five
implementation scenarios, but decrease slightly with increasing state MMM participation. At the
national level, aggregate costs per case of avoided fatal cancer (including State costs) range from
$1.1 to $2.0 million per year. The overall costs per fatal cancer avoided are considerably lower
than the costs per fatal cancer avoided for water mitigation only that are estimated in Section 10.7.
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Table 9-6, Cost per Fatal Cancer Avoided By System Size for Each Scenario (Includes Only
System Costs), $M, 1997 (MCL = 300 pCi/1)
System Size
15-100
101-500
501-3,300
3,301-10,000
10,001-
100,000
> 100,000
OVERALL
Total Fatal
Cancers
Avoided
2.9
10.0
10.2
25.9
12.8
62.4
Scenario A
46.4
12.3
2.2
0.8
0.4
0.2
1.94
Scenario B
40.4
10.9
1.9
0.7
0.3
0.1
1.72
Scenario C
34.4
9.6
1.7
0.6
0.3
0.1
1.49
Scenario D
28.4
8.3
1.4
0.5
0.2
0.1
1.28
Scenario E
19.7
6.4
0.9
0.4
0.1
0.1
10. COSTS AND BENEFITS OF 100% COMPLIANCE WITH AN MCL
; i !
This section presents benefit, cost, and impact estimates, assuming 100% compliance with
optional MCLs, for the proposed rule. Costs and benefits assuming various percentage
compliance with the AMCL and MMM program are shown in Section 9 of this analysis. Section
10.1 provides an overview of the approaches used to estimate costs and benefits. Section 10.2
summarizes the results of the risk reduction and benefit calculations. Section 10.3 summarizes
the costs of radon mitigation in water supplies. Section 10.4 provides a more detailed picture of
costs to groundwater systems of radon mitigation, and Section 10.5 discusses the costs to
households served by these systems. Section 10.6 compares the incremental costs and benefits of
successively more stringent radon levels. Section 10.7 summarizes the aggregate and incremental
costs of preventing fatal cancers and Section 10.8 provides an analysis of the uncertainty
associated with the benefit and cost estimates.
10.1 Overview of Analytical Approach
; ;i ;
11111 , i J . i
Consistent with the discussion in Section 4.1, the costs and benefits of radon mitigation
have been calculated for maximum radon exposure levels of 100, 300, 500, 700, 1,000, 2,000, and
4,000 pCi/1. For each of these levels, central tendency estimates of costs and benefits have been
developed. These central tendency estimates represent EPA's best estimate of the average costs
and benefits that would accrue under the different maximum radon level
i | j
The health benefits of the rule that have been quantitatively evaluated consist of reduced
fatal and non-fatal cancer risks. Cancer risks, and the reductions in risks associated with
reductions in radon in drinking water, have been calculated for the general population. In
September, 1999 - Draft Document
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addition, risk reduction and benefits calculations have been performed separately for non-(never)-
smokers and for ever-smokers, the latter being much more sensitive to radon and radon progeny
inhalation exposures. The health benefits of reductions in radon levels have been calculated using
the monetary surrogates for these benefits, as described in Section 6.
The elements of radon mitigation that have been included in cost calculations include
capital and O&M costs, along with pre- and post-treatment costs where appropriate, as well as
monitoring costs. Costs are calculated for each groundwater system size category. The
proportions of sources and systems requiring mitigation are calculated using the distributions of
influent groundwater given in Section 5.2, and the costs of mitigation are calculated using
assumptions of pre-existing technologies, likely responses to regulation, and costs of radon
mitigation technologies, that are summarized in Section 7. National cost estimates are derived by
summing the estimated mitigation costs incurred by all the system size categories. Record
keeping and reporting costs, along with implementation costs to States and government entities,
are addressed in Section 8.1 and in the preamble for the proposed rule. The analysis of the costs
and benefits of various percentages of states and community water systems choosing the
AMCL/MMM option is presented in Section 9.
The costs and benefits of the proposed radon rule will result in economic impacts on
affected individuals, corporate entities, and government entities. In this analysis, economic
impacts on water systems and households have been evaluated using two indicators, (1) the cost
of radon mitigation to systems of different sizes and ownership types, and (2) potential increases
in water costs to households as a proportion of income due to the pass-through of radon mitigation
costs.
Costs have been estimated for systems of three ownership types. The first type is public
systems, which are those owned by government entities. Private systems consist of investor-
owned entities that provide drinking water as their primary line of business. Ancillary systems
include drinking water systems that are operated incidentally to another business. The majority of
ancillary systems are operated by mobile home parks, but some are run by schools, hospitals, and
other entities. Non-Transient Non-Community Water Systems (NTNCWSs) are not covered by
the radon rule and thus have not been included in the proposed rulemaking. An analysis of the
potential benefits and costs to NTNCWSs is shown in Appendix ,F. In this section, the economic
impacts of the multimedia mitigation (MMM) programs on systems or households have not been
calculated, because there is limited information at present as to how these programs would be
funded or upon whom the costs would fall. The costs and impacts of possible MMM
implementation options are discussed in more detail in Section 9.
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10.2 Health Risk Reduction and Monetized Health Benefits
^ The probabilistic risk model described in Section 6 was used to calculate the cancer risk
reduction benefits of the various radon levels. Distributions of individual risk as a function of
influent radon levels were developed for each system size based on exposure assumptions
developed by the NAS and EPA. General population risks (fatal cancers per year) were
calculated by multiplying the estimated individual risks by the estimated populations exposed to
water from each size system. The numbers of non-fatal cancers per year associated with radon
exposures were also estimated using the mortality rates for the various radon-related cancers
shown in Section 6.2. Risks and risk reduction estimates for ever- and never-smokers were
calculated the same way as general population risks, except that different Unit Risk values,
derived for these groups by NAS and EPA, were used instead of the general population Unit Risk
value. Risk reduction benefits were calculated by subtracting the estimated population risks at a
given radon level from the baseline (pre-regulation) population cancer risk due to radon exposure.
Monetized benefits were calculated using a central tendency value of statistical life (VSL) of $5.8
million per fatal cancer, and a central tendency willingness-to-pay estimate to avoid non-fatal
cancer of $536,000 dollars.
National population risks and risk reduction benefits for different radon exposure levels
are summarized in Table 10-1. Under the baseline scenario, the estimated number of fatal cancers
per year caused by radon exposures in domestic water supplies is 168, and the number of non-fatal
cancers is 10.7. As radon levels decrease, residual risks decrease, and the risk reduction benefits
increase. Since only a small proportion of the population are exposed at levels above 2,000 pCi/1,
the benefit of controls in this exposure range is relatively small (fewer than 7 cancers prevented
per year). The health risk reduction benefits then increase as radon levels decrease, because larger
populations are affected as more systems are required to mitigate exposures.
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Table 10-1. Risk Reduction and Residual Cancer Risk from
Reducing Radon in Drinking Water
Radon
Level
(pCi/1 in
water)
(Baseline)
4,0002
2,000
1,000
700
500
300
100
Residual Fatal
Cancer Risk
(Cases per
Year)
168
165
160
150
141
130
106
46.8
Residual Non-
Fatal Cancer Risk
(Cases per Year)
9.7
9.5
9.4
8.8
8.3
7.6
6.1
2.8
Risk Reduction
(Fatal Cancers
Avoided per Year)1
0
2.9
7.3
17.8
26.1
37.6
62.0
120
Risk Reduction
(Noil-Fatal Cancers
Avoided per Year)1
0
0.2
0.4
1.1
1.5
2.2
3.6
7.0
Notes: 1. Risk reductions and residual risk estimates are slightly inconsistent due to rounding.
2. 4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA provisions of Section 1412(b)(13).
At the lowest level (100 pCi/1) analyzed, the residual cancer risk (the cancer risk occurring
after controls are installed) is approximately 47 fatal cancers per year. The risk reduction from
this radon level is 120 fatalities per year, a reduction of approximately 72 percent from the
baseline of 168 per year. A similar reduction in non-fatal cancers is seen with decreasing radon
levels.
The monetary valuation methods discussed in Section 6 were applied to these risk
reductions to generate estimates of monetary benefits, as shown in Table 10-2. As noted above,
the central tendency benefits estimates are based on a VSL of $5.8 million (1997$) and a WTP to
avoid fatal cancers of $536,000 (1997$). Central tendency estimates of total monetized benefits
range from $17.0 million per year for a level of 4,000 pCi/1 up to $702 million for the most
stringent level of 100 pCi/1.
The data in Table 10-2 also show that the benefits associated with reductions in fatal
cancers account for the great majority (more than 99 percent) of the estimated monetary benefit at
all radon exposure levels. This is due both to the far greater number of fatal cancers prevented
and to the relative magnitude of the VSL and WTP values.
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Table 10-2. Estimated Monetized Health Benefits from
Reducing Radon in Drinking Water (1997)
Radon Level
(pCi/1)
Baseline
4,0002
2,000
1,000
700
500
300
100
Health Benefits,
Fatal Cancer Cases'
(SMillions, per year)
0
16.8
42.3
103.0
151.4
218.1
359.6
696.0
Health Benefits,
Non-Fatal Cancer
Cases'
<"SMiIIionsT per vearl
0
0.1
0.2
0.5
0.8
1.2
1.9
3.8
Total Health Benefits,
(SMillions per year)
0
17.0
42.7
103
152
219
362
702
Notes:
1. Fatal and non-fatal health benefits may not match perfectly due to rounding errors
2, 4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA provisions of Section 1412(b)(13).
As noted in Section 10.1, cancer risk reductions and associated health benefits were
calculated for ever- and never-smoking populations. This was done because ever-smokers are
considerably more sensitive to inhalation exposure to radon and radon progeny than are never-
smokers. Thus risk reductions and benefits are greater for ever-smokers than for never-smokers,
as shown in Tables 10-3 and 10-4.
i
• i
The estimated population risk reductions from control of radon in drinking water for ever-
smokers (who are assumed to make up 58 percent of the population) are approximately four times
greater than those for never-smokers (42 percent of the population.) Another way to say this is
that ever-smokers realize approximately 80 percent of the risk reduction and associated benefits.
If the proportions of ever- and never-smokers in the population were to change, then both the
overall magnitude of the benefits and the proportion of benefits realized by smokers would
change. Currently, there is a trend for decreasing population prevalence of smoking in the U.S. If
this trend continues, benefits, and the proportions of benefits accruing to smokers, may be lower
than the values shown in Tables 10-3 and 10-4.
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Table 10-3. Risk Reduction and Monetized Benefits Estimates For Ever-Smokers1
Fatal Cancers Avoided Per Year
Non-Fatal Cancers Avoided Per
Year
Annual Monetized Health
Benefits (SMillions, 1997)
Radon Level, pCi/1
40002
2.4
0.1
13.7
2000
5.9
0.3
34.4
1000
14.3
0.8
83.4
; 700
'.21.1
1.1
'122.8
500
30.3
1.7
176.6
300
50.0
2.7
291.6
100
97.0
5.4
565.6
Notes:
1 . Risk reductions for ever- and never-smokers were estimated using the NAS unit risk estimates summarized in
Table 3-4, an ever-smoking prevalence of 58% males and 42% females, a central VSL estimate of $5.8 million
( 1 997$), and central WTP estimate to avoid non-fatal cancer of $536,000 ( 1 997$).
2. 4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on the SDWA provisions of Section
Table 10-4. Risk Reduction and Monetized Benefits Estimates for Never-Smokers1
Fatal Cancers Avoided Per Year
Non-Fatal Cancers Avoided Per
Year
Annual Monetized Health Benefits
(SMillions, 1 997) - Central
Tendency
Radon Level, pCi/1
40002
0.6
0.05
3.3
2000
1.5
O.I
8.3
1000
3.6
0.2
20.3
700
5.2
0.3
29.7
500
7.5
0.5
43.0
300
12.2
0.8
70.4
100
23.6
1.6
137.1
1. Health benefits are estimated as explained in Table 10.3
2.4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section 1412(b)(13).
10.3 Costs of Radon Mitigation
This section presents the results of calculations of the cost of groundwater radon
mitigation assuming all systems comply with the MCL. National aggregate costs are presented for
the various radon levels. Capital, O&M, and monitoring costs are also broken out. All costs are
incremental (relative to the current baseline, as described in Section 5.2), stated in 1997 dollars.
Capital costs were annualized using a seven percent discount rate and a 20-year amortization
period.
September, 1999 - Draft Document
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10.3.1
Aggregate Costs of Water Treatment
The total annual nationally aggregated cost varies significantly for different radon
exposure levels. Total national cost estimates for CWSs are presented in Table 10-5. As shown
in this table, water mitigation costs increase substantially from the highest radon level analyzed
($43.1 million at 4000 pCi/1) to the lowest level analyzed ($816.2 million at 100 pCi/1). These
cost increases are due to the increase in the number of systems that need to mitigate radon as the
radon level is reduced.
Table 10-5. Estimated Annualized National Costs of Reducing Radon Exposures Assuming 100%
Compliance with an MCL (SMillion, 1997)
Radon Level
(pCi/1)
4,0003
2,000
1,000
700
500
300
100
Central Tendency Estimate
of Total Annualized Water
Mitigation1
34.5
61.1
121.9
176.8
248.8
399.1
807.6
Total Annualized National
Costs2
43.1
69.7
130.5
185.4
257.4
407.6
816.2
Total Cost Per Fatal
Cancer Case Avoided
14.9
9.5
7.3
7.1
6.8
6.6
6.8
I. Costs include treatment, monitoring, and O&M costs.
2. Costs include treatment, monitoring, O&M, recordkeeping, reporting, and state costs for the administration of
water programs.
3. 4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section
The costs of radon mitigation include annualized capital, O&M, and monitoring costs.
These cost elements are broken out in Table 1 0-6. Generally, the annualized capital and O&M
costs of radon mitigation are comparable, with O&M costs slightly exceeding capital costs at high
radon levels, with the reverse at the more stringent radon levels. Capital and O&M costs
dominate the total costs, except at the least stringent radon levels, where monitoring costs account
for a significant (up to 30 percent) fraction of total radon mitigation costs.
I
, j
10.4 Costs to Community Water Systems
September, 1999 -DraftDocument
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This section discusses the water mitigation costs that will be incurred by individual CWSs
at the various maximum radon levels analyzed. Systems above the target radon level will incur
monitoring costs and treatment costs. Systems below the target radon level will incur only
monitoring costs. Thus, the first step in the analysis is to estimate' the number of systems that will
have one or more sources above the radon levels, and therefore incur mitigation costs.
Table 10-6. Capital and O&M Costs of Mitigating Radon
in Drinking Water (SMillion, 1997)
Radon Levels
(pCi/1)
4000*
2000
1000
700
500
300
100
Annual ized
Capital Cost
((a). 7%)
12.1
27.9
64.3
97.4
141.0
232.5
484.1
Annual O&M Cost
8.3
19.1
43.5
65.2
93.6
152.4
309.4
Annual Monitoring
Costs
14,1
14vl
14,1
1411
14.1
14,1
14.1
Total Costs
34.5
61.1
121.9
176.8
248.8
399.1
807.6
*4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section
The numbers of systems and groundwater sources that would exceed various radon levels
were calculated using the distributions of radon levels for each system size category, as described
in Section 5.2. The number of CWSs needing to mitigate one or jnore water sources increases
with each decrease in the maximum allowable radon level, as shown Table 10-7. The table also
shows that the large majority of affected systems, regardless of radon level, are very, very small
(serving 25-500 people) or very small (serving 501-3,300 people). For radon levels of 1,000
pCi/1 or greater, approximately 94 percent of the affected systems fall into these two categories.
For radon levels between 100 and 700 pCi/1, the two smallest system size categories account for
between 74 percent and 85 percent of the systems that would need to mitigate radon.
September, 1999 - Draft Document
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Table 10-7. Number of Community Ground Water Systems
With One or More Sources Exceeding Maximum Radon Levels'
Exposure
Level
(pCi/i)
40002
2000
1000
700
500
300
inn
ws
(25-100)
592
1,299
2,587
3,547
4,658
6,690
11 174
(101-500)
974
1,743
2,977
3,846
4,831
6,611
in 678
VS
(501-
3,000)
165
457
1143
1,731
2,442
3,760
6 797
S
(3,301-
10,000)
30
86
231
370
558
940
1 7QI
M
(10,000-
100,000)
15
52
156
252
374
609
1 1 10
L
(>100K)
1
3
7
12
18
29
54
Total
1,777
3,640
7,101
9,758
12,881
18,639
1L 54?
Notes:
1. Calculated from radon distributions in Section 5.2 using lognormal approximations
2. 4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section
Total radon mitigation costs per systems (annualized capital. O&M and monitoring) were
calculated for the different size systems and for public and privately-owned systems (Table 10-8.)
For small to medium sized systems (serving less than 10,000 people) that have one or more
sources exceeding radon levels, the average mitigation cost per system increases only slightly as
the radon levels decrease. For the smallest systems, the increase in costs from the least stringent
radon level (4,000 pCi/1) to the most stringent level (100 pCi/1) is approximately 7 percent for
public systems and about 6 percent for privately-owned systems. For systems serving 3,300 to
10,000 people, the average mitigation costs increase approximately 49 percent for public systems
and 39 percent for privately-owned systems.
This pattern is due in large part to the limited number of treatment options assumed to be
available to systems that may (in aggregate) be encountering a relatively wide range of radon
levels. Also, as radon levels become more stringent, the increasing average mitigation costs for
systems already affected is offset by the relatively low costs for the systems that just exceed the
more stringent levels. These latter systems can be expected to have lower average costs, because
only a limited amount of radon removal is needed.
For larger systems, average mitigation costs increase more rapidly with decreasing radon
levels. For public and privately-owned medium systems (serving 10,000-100,000 people), the
average mitigation costs increase approximately 265 percent from a radon level of 4,000 pCi/1 to a
level of 100 pCi/1. For large systems (serving more than 100,000 people), average mitigation
costs increase approximately 285 percent over the same range of radon levels. The large changes
in costs are probably due primarily to the need for the larger systems to treat larger numbers of
September, 1999 - Draft Document
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sources as radon levels decrease. At relatively high radon levels, only one or two sources per
system may need mitigation, while at the lower levels, substantially all of the sources in the larger
systems may need mitigation.
The bottom line of Table 10-8 shows the average costs incurred by the systems that do not
have any source exceeding radon levels. In this analysis, monitoring costs per system below
radon levels will be the same for all systems in each size category; because monitoring costs are
assumed to be dependent only on system size and not on concentration2. Under these
assumptions, average annual monitoring costs range from $300 for the very very small systems to
approximately $2,600 for large systems, again due to the larger number of sites requiring
monitoring.
Table 10-8. Average Annual Cost Per System (SThousands, 1997)
Radon
Level
(pCi/1)
40001
2000
1000
700
500
300
100
All
Public Systems Exceeding Radon Levels
vvs
(25-
100)
8.2
8.3
8.4
8.5
8.5
8.6
8.9
vvs
(101-
500)
12.4
12.6
12.9
13.0
13.2
13.5
14.6
vs
18.5
19.1
26.6
27.2
27.8
28.8
31.0
s
49.3
51.3
60.1
61.9
63.7
67.4
77.2
M
82.3
94.1
115.9
129.0
143.2
167.1
219.1
L
484.9
560.7
693.4
758.3
847.8
1000.4
1345.3
Private; Systems Exceeding Radon Levels
vvs
(25-
100)
7.6
7.7
7.8
7.9
7.9
8.0
8.2
vvs
(101-
500)
10.1
10.3
10.5
10.6
10.7
10.9
11.6
vs
15.6
16.2
16.8
17.1
17.5
18.1
19.1
s
43.7
45.5
47.3
48.7
50.3
53.3
61.8
M
72.1
82.4
100.2
111.7
123.9
144.7
189.6
L
468.5
541.8
670.2
752.7
841.6
992.9
1333.1
Annual Per System Cost for those Systems Below Radon Levels: Monitoring Costs Only
0.3
0.3
0.4
0.6
1.1
2.6
0.3
0.3
0.4
0.6
1.1
2.6
1. 4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements at Section 1412(b)(13).
2 As noted in Section 8, some systems where initial monitoring establishes that radon
levels are low (e.g., less than one-half the MCL or below detection limits) may be allowed to
monitor less frequently, thus reducing monitoring costs for those systems after the first year. The
proportions of systems eligible for reduced monitoring will increase with increasing radon levels.
Thus, monitoring costs may be overestimated for the higher levels.
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10.5 Costs and Impacts to Households
Water systems, when faced with the expense of mitigating radon, will pass some portion
of these costs on to their customers. In the extreme, they could pass all of the costs on, and not
reduce their net profit. Using this assumption, the potential increases of the costs to water
consumers have been calculated for each system size category and for public and private systems.
The distinction between public and private systems is important not only because the costs per
system are different for public versus private systems, but also because the smallest private
systems tend to serve fewer households than do the smallest public systems. Therefore,
households served by a small private system must, on average, bear a greater percentage of the
CWS's cost than does the average household served by a public CWS. This is particularly
important where capital costs make up a large portion of total radon mitigation costs.
For systems with one or more sources above the radon levels, customers must bear both
the costs of radon mitigation and the costs of monitoring to assure compliance. However,
households served by systems with no sources above the radon levels will incur monitoring costs
only and no treatment costs. The very low household costs for systems with all sources below
radon levels are not included in this analysis.
Annual radon mitigation costs per household are presented in Table 10-9 for households
served by public and private CWSs. As expected, at all radon levels, costs per household increase
as system size decreases. Costs per household are higher for smaller systems than for larger
systems for two reasons. First, smaller systems serve far fewer households than larger systems
and, consequently, each household must bear a larger proportion of radon mitigation costs.
Second, smaller systems tend to have higher influent radon levels that require more expensive
treatment methods (e.g., 99 percent removal efficiency rather than 50 percent) to achieve the
target radon level.
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Table 10-9. Annual Radon Mitigation Costs per Household for Community Water Systems
to Treat to Various Radon Levels ($, 1997 )*
Radon
level
(pCi/1)
4000"
2000
1000
700
500
300
100
Households Served by PUBLIC Systems Above
Radon level
VVS
(25-
100)
256.5
259.0
262.5
264.4
266.3
269.5
278.8
VVS
(101-
500)
91.0
92.8
94.8
96.0
97.1
99.3
107.1
VS
22.7
23.5
24.6
25.2
25.9
26.9
29.1
S
14.3
14.9
15.4
15.9
16.4
17.4
20.1
M
6.2
7.1
8.6
9.6
10.6
12.4
16.2
L
4.5
5.2
6.4
7.2
8.1
9.5
12.8
Households Served by PRIVATE Systems
Above Radon level
VVS
(25-
100)
372.4
375.8
380.5
383.1
385.6
389.8
401.5
VVS
(101-
500)
14.1.1
143.7
146.3
147.8
149.4
152.2
162.4
VS
30.3
31.2
32.6
33.4
34.2
35.5
37.9
S
22.8
23.7
24.7
25.4
26.2
27.7
32.1
M
6.6
7.5
9.1
10.1
11.2
13.1
17.1
L
4.4
5.1
6.3
7.1
7.9
9.4
12.6
*Reflects total household costs for systems to treat down to these radon levels. Because EPA expects that most systems will
comply with the AMCL/MMM, most systems will not incur these household costs. ;
**4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section
Another significant finding regarding annual cost per household is that, like the per-system
costs, household costs (which are a function of per system costs) are relatively constant across
different radon levels for the smaller system size categories. For example, the household cost to
achieve a radon level of 100 pCi/1 is only five percent higher than the household costs of meeting
a level of 4,000 pCi/1 for the smallest public system. The analogous difference for the very very
small private systems is only seven percent.
To further evaluate the impacts of radon mitigation costs on the households that must bear
them, the costs per household were compared to median household income data for households in
each system-size category. The analysis includes only households served by CWSs with influent
radon levels at one or more sources that are above the various radon levels. Households served by
systems with lower radon levels may incur incremental costs due to new monitoring requirements,
but these costs are not significant at the household level.
Household impacts are presented in Table 10-10 for public and private CWSs,
respectively. For all system sizes but one (very very small systems), household costs as a
percentage of median household income are less than one percent: Impacts exceed one percent
September, 1999 - Draft Document
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only for households served by very very small private systems at all radon levels, and for very
very small public systems at radon levels below 500 pCi/1. The highest household impact for the
very very small private systems is 1.51 percent of median income to meet a radon level of 100
pCi/1, and the highest impact for very very small public systems is 1.17 percent, also at 100 pCi/1.
Similar to the cost per household results on which they are based, household impacts exhibit little
variability across radon levels for the smaller systems.
1 j
1 i
Table 10-10. Per Household Impact by Community Ground Water Systems as a
Percentage of Median Household Income
Radon II Household Impact for Public Systems Above
level Radon Level
(pCi/1) (percent of median household income)
4000 '
2000
1000
700
500
300
100
VVS
(25-
100)
0.86
0.92
0.96
0.98
1.00
1.05
1.17
VVS
(101-
500)
0.30
0.36
0.38
0.38
0.39
0.40
0.44
VS
0.13
0.12
0.13
0.13
0.13
0.14
0.15
S
0.06
0.05
0.05
0.06
0.06
0.06
0.07
M
0.03
0.02
0.02
0.03
0.03
0.03
0.05
L
0.02
0.01
0.01
0.02
0.02
0.02
0.03
Household Impact for Private Systems Above
Radon Level
(percent of median household income)
VVS
(25-
100)
1.12
1.19
1.24
1.27
1.30
1.35
1.51
VVS
(101-
500)
0.35
0.42
0.44
0.45
0.45
0.47
0.51
VS
0.16
0.16
0.16
0.17
0.17
0.18
0.19
S
0.07
0.09
0.09
0.09
0.09
0.10
0.12
M
0.04
0.02
0.03
0.03
0.03
0.04
0.05
L
0.02
0.01
0.01
0.01
0.01
0.02
0.02
Notes:
1. 4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SD WA requirements of Section
10.6 Incremental Costs and Benefits
,, ' : ' I !
i I
Incremental costs and benefits are those that are incurred or realized in going from a given
radon level to the next more stringent level, e.g., from the "baseline" to 4,000 pCi/1 or from 300
pCi/1 to 100 pCi/1. Incremental costs are useful in developing estimates of the cost-effectiveness
of successively more stringent requirements. Such measures will be developed in Section 10.7
.:.!••, i il
Table 10-11 shows the incremental total national risk reduction, radon mitigation costs and
benefits for the various radon levels. Risk reduction and monetary benefits in this case were
calculated for the general population, including both smokers and non-smokers. It can be seen
that the cancer risk reduction, monetized benefits, and radon mitigation costs all increase with
decreasing radon levels, and in fact, they all increase more rapidly as the radon levels become
September, 1999 - Draft Document -128-
-------
more stringent. For all of the radon levels, incremental radon mitigation costs exceed the
monetized health benefits. At a radon level of 4,000 pCi/1, radon mitigation costs exceed
monetized benefits by a factor of approximately 2. As will be seen in the following section, the
incremental cost-effectiveness of radon mitigation (as measured'in costs per life saved) is also the
greatest for these radon levels.
Table 10-11. Estimates of the Annual Incremental Risk Reduction, Costs and Benefits of
Reducing Radon in Drinking Water Assuming 100% Compliance With an
**™i^^^*^^^^"^M'"'^^^^^™"M'™M'
Radon Level, pCi/1
Incremental Risk Reduction, Fatal
Cancers Avoided per Year
Incremental Risk Reduction, Non-
Fatal Cancers Avoided per Year
Annual Incremental Monetized
Benefits, SMillions per Year
(1997)
Annual Incremental Radon
Mitigation Costs, $Millions per
Notes: i
1. 4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section
1412(b)(13).
2. Costs include treatment, monitoring, and O&M costs only.
Because the risk reduction for ever- and never-smokers are different, the incremental
benefits of radon levels in drinking water are different for the two groups. The incremental
monetary benefits and radon mitigation costs for ever- and never-smokers are shown in Tables 10-
12 and 10-13, respectively. As expected, the incremental benefits for ever-smokers are greater
than those realized by never-smokers.
September, 1999 - Draft Document
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Table 10-12. Incremental Risk Reduction, Costs, and Monetized Health Benefits for Ever-
Smokers
|| | Radon Level, pCi/I
Incremental Risk
Reduction, Fatal Cancers
Avoided per Year
Incremental Risk
Reduction, Non-Fatal
Cancers Avoided per
Year
Annual Incremental
Monetized Benefits,
SMillions per Year
(1997)
Annual Incremental
Radon Mitigation Costs,
SMillions per Year
(I997)2
4000 '
2.4
0.1
13.7
17.3
2,000
3.5
0.2
20.7
13.3
1,000
8.4
0.5
49.0
30.4
700
6.8
0.3
39.4
27.4
500
9.2
0.6
53.8
36.0
300
19.7
1.0
115
75.2
100
47.0
2.7
274
204
Notes:
1.4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section
1412(bX13).
2. Costs include treatment, monitoring, and O&M costs only.
September, 1999 - Draft Document -130-
(•" • ,.• I '„,',. .. , : kllli: .
fe,;;, „ , ilii
i . .,iii ,i. .1 liiii;. I!
-------
Table 10-13. Incremental Risk Reduction, Costs, and Monetized Health Benefits for Never
Smokers
'
Incremental Risk
Reduction, Fatal Cancers
Avoided per Year
Incremental Risk
Reduction, Non-Fatal
Cancers Avoided per
Year
Annual Incremental
Monetized Benefits,
SMillions per Year
(1997)
Annual Incremental
Radon Mitigation Costs,
SMillions per Year
(1997)2
=====
=====
4000 '
0.6
0.05
3.3
17.3
•• —
2,000
0.9
0.05
5.0
13.3
— . -
=====
Rad«
=======
1,000
2.1
0.1
12.0
30.4
•
on Level, p
===
700
1.6
0.1
9.4
27,4
=====
Ci/1
500
2.3
0.2
13.3
36.0
—
=========
300
4.7
0.3
27.4
75.2
==========
100
11.4
0.8
66.7
204
=====
1 °4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section
1412(b)(13).
2. Costs include treatment, monitoring, and O&M costs only.
10.7 Costs per Life Saved
One measure of the cost-effectiveness of the various radon levels is the cost of radon
mitigation per fatal cancer avoided. As expected, the costs per life saved vary widely across the
different radon levels and for the different size systems.
Table 10-14 shows the total mitigation costs per fatal cancer avoided for all systems for
the general population, ever-smokers, and never-smokers. For all three populations, costs per life
saved decrease with decreasing radon levels, reach a minimum at 300 pCi/1, and then increase
slightly at the radon level of 100 pCi/1. As expected, the costs per life saved are lowest for the
ever smokers, highest for never-smokers, and the cost per life saved for the general population
falls in between these two values. For ever-smokers, the cost per life saved at the 300 pCi/1 radon
level is $4.0 million. For never smokers, the corresponding values is $16.6 million, and the cost
per life saved at 300 pCi/1 (assuming all systems comply with the MCL) for the general population
is $6.6 million.
September, 1999 - Draft Document
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Table 10-14. Total Costs per Fatal Cancer Avoided as a Function of Radon Level For 100%
Compliance with an MCL, $Millions
Population
Radon Level, pCi/1
4,000
2,000
1,000
700
500
300
100
General Population
14.9
9.5
7.3
7.1
6.8
6.6
6.8
Ever-Smokers
7.3
5.2
4.3
4.2
4.1
4.0
4.2
Never-Smokers
30.8
21.5
17.6
17.4
For never-smokers, the cost per life saved at 4,000 pCi/1 is $30.8 million, and decreases to
$16.6 million at 300 pCi/1. For the general population, costs per life saved at radon levels
between 4,000 pCi/1 and 100 pCi/1 vary from $6.8 million to $14.9 million.
I
Table 10-15 provides a comparison of the total mitigation costs and the reduction in fatal
cancers for the different system sizes and radon levels. It can be seen from this table that the
mitigation costs and risk reduction benefits are not distributed equally across the system size
categories. Table 10-16 provides a comparison of the total benefits and the reduction in fatal
cancer cases for each system size at various radon levels.
September, 1999 - Draft Document
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10.8 Uncertainty in Benefit and Cost Estimates
10.8.1 Uncertainties in Risk Reduction Estimates
The models used to estimate radon-related cancer risks, risk reduction, and monetary
benefits take many inputs which are both uncertain and highly variable. EPA has used a two-
dimensional Monte-Carlo model to derive upper and lower confidence limits on radon-related
risks and risk reduction estimates. The results of this analysis are summarized in the second and
third panels of Table 10-17.
Table 10-17. Upper and Lower Confidence Limits on Risk, Risk Reduction,
Radon
Level
(pCi/l)
Baseline
4,000
2,000
1,000
700
500
300
100
Fatal Cancers per Year
Lower
Bound
80.5
79.7
77.2
76.9
74.2
69.6
56.1
25.1
Central
Tendency
168
165
160
150
141
130
106
46.8
Upper
Bound
288
279
269
221
214
192
150
67.5
Fatal Cancers Avoided per
Year
Lower
Bound
0
0.8
3.3
3.5
6.3
10.9
24.4
55.0
Central
Tendency
0
2.9
7.3
17.8
26.1
37.6
62.0
120
Upper
Bound
0
8.7
27.0
58.6
74.5
95.8
138
220
Monetized Health Benefits,
SMillions per Year l
Lower
Bound
I^^BM^HMH
0
4.7
19.2
20.4
36.7
63.6
142
321
Central
Tendency
•^••••^••i^HM
0
17.0
42.7
103
152
219
362
702
Upper
Bound
^••^^•^
0
50.7
157
342
434
559
805
1,283
^Calculated using VSL of $5.8 million for fatal cancers and WTP to avoid non-fatal c'ancers of $536,000.
The central tendency estimate of population cancer risk under baseline conditions (no
radon limit in drinking water) is 168 fatal cancers per year. The lower-bound estimate of baseline
cancer risks (the 5 percent lower confidence limit) is 80.5 fatal cancers per year, and the upper-
bound estimate (the 95 percent upper confidence limit) is 288 cancers per year. The difference
between the lower-bound and upper-bound cancer risk estimates is thus approximately 208 fatal
cancers per year. The upper bound population risk estimate is 1.7 times the central tendency
estimate and the lower bound approximately 48 percent of this value.
September, 1999 - Draft Document
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,| . , : „
_ The distributions of estimated population cancer risks for the two proposed radon levels
are similar to those seen in the baseline case. For a radon level of 4,000 pCi/1 the estimated
population cancer risks range from a lower-bound value of 79.7 fatal cancer per year to an upper-
bound value of 279 cancers per year, with a central tendency estimate of 165. Population cancer
risk estimates for a radon level of 300 pCi/1 range from 56. 1 fatal cancer per year (lower-bound) to
150 cancer per year (upper-bound) with a central tendency value of 106 cancers per year The
estimated reduction in fatal cancers per year for a radon level of 4,000 pCi/1 range from 0 8 to 8 7
with a central tendency value of 2.9. For a radon level of 300 PCi/I, risk reduction estimates range
from 24.4 to 138 fatal cancers per year, with a central tendency estimate of 62.0. Risk and risk
reduction estimates for the remainder of the radon levels show the same general pattern
Monetized benefit estimates were developed using the central tendency estimates of VSL and
WTP, as shown in Table 10-17.
: j , :
10.8.2 Sensitivity of Benefits Estimates to Variability in The Value of Statistical Life
. As nPte4 above, the benefits estimates that have been discussed so far were derived using
f.?ln/ve5rlmuateS5the m°netary Dogates for fatal and non-fatal cancers. The value of statistical
lte ( ™J*g? been aPPro*»™ted by a single-value estimate of $5.8 million, and the willingness-
to-pay (WTP) to avoid non-fatal cancer has been modeled as a constant with a value of $536 000
These are the central tendency values derived by the EPA based on studies from the economic
hterature and previous regulatory analyses (USEPA 1999B, 19981). Because the VSL is much
larger than the WTP value, and because there are many more fatal than non-fatal radon-related
cancers, the VSL value dominates the total monetary benefit calculation.
j
The studies that have been reviewed by EPA (USEPA 1 999B) have developed a wide
range of VSL values, from $700,000 to $16.3 million. This implies that the monetized benefits of
reduced cancer risks could take a wide range of values, depending upon the VSL that is chosen
To estimate bounds on the range of benefits estimates, EPA has performed the benefits
ca culations using the upper- and lower-bound VSLs identified above. The results of these
calculations are presented for the various radon levels in Table 10-18.
n t- .costs estimates range from $123 million per year to $2.74 billion per year
reflecting the 2j-fold difference between the lower-bound ($0.7 million) and upper-bound ($163'
?±0nlefm?teS,°f \SL' The Iower and "PPer-bound estimates of the monetized benefits of the
4,000 PCi/1 radon level are $2.1 million and $47.6 million per year, respectively. The ranges of
monetized benefits for the other radon levels follow the same pattern, with the lower- and upper-
bound estimates covering a 23-fold range about the central tendency values
September, 1999 - Draft Document
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Table 10-18. Monetized Benefits as a Function of the Value of Statistical Life (VSL)
Estimates
Value of Statistical Life
(SMillions)
Baseline Costs of Fatal and
Non-Fatal Cancers,
SMillions per Year
Radon Level, pCi/1
4,000
2,000
1,000
700
500
300
100
Lower Bound
0.7
123
Central Tendency
5.8
980
Upper Bound
16.3
2,744
Monetized Benefits (SMillions per Year)
2.1
5.4
13.0
19.1
27.5
45.3
88.1
17.0
42.7
104
152
219
362
702
47.6
119
290
427
615
1,012
1.966
10.8.3 Variability in Mitigation Cost Input Variables
To evaluate the potential variability in the radon mitigation cost estimates, a limited Monte
Carlo sensitivity analysis was undertaken. This analysis differed from that of the benefit
estimates in that many of the input variables were allowed to vary, instead of only a few. In
addition, the analysis was "one-dimensional" instead of two-dimensional, addressing only
variability, and not uncertainty. The outputs of this model tell how the known variability in the
input values effects the output values, but does not address the affects of uncertainty (lack of
knowledge) about the inputs. The inputs that varied were: :
• Numbers of total systems in the various size categories
• Numbers of sources per systems in different size categories
• Distributions of populations served by size category ;
• Coefficients used to determine flow rates as a function of population served
September, 1999 - Draft Document
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• Daily household water consumption
• Proportions of systems and sources exceeding radon regulatory limits
" ' • ' , i ' i| i
i 'I "l
• Unit costs (capital and O&M) of major radon mitigation technologies (aeration and central
GAC)
Each of these inputs was modeled using probability distributions that reflected the state of
the available da|a. The input distributions were designed so that the variability in the inputs
reflected the range of variability seen in the real-world data. In some cases, (distributions of
populations served, daily household water consumption, unit costs) variability was estimable from
SDWIS, the CWSS, or other sources. In the case of the total numbers of systems of different
sizes, variability was estimated using professional judgement. The estimated variability was
greatest for the smallest systems (plus or minus 10 percent), less for the moderate size systems
(plus or minus five percent), and the numbers of the largest systems (serving greater than 100,000
customers) was assumed to be known with certainty. The variation in the proportions of systems
and sources above radon levels was estimated based on EPA's recent analysis (USEPA 1999C) of
inter- and intra- system radon variability in radon levels.
In addition to these inputs, the distributions of probabilities in the mitigation technology
selection matrix ("decision tree", see Table 7-3) was allowed to vary as well. Three decision tree
matrices were developed by EPA, corresponding to a central tendency estimate of the proportions
of systems choosing specific mitigation technologies, and to lower- and higher-cost distributions
of technology selection. When the simulation was run, the central tendency matrix was selected
in 80 percent of the iterations, and the low- and high- cost decision matrices were selected in ten
percent of the iterations each.
The model was run for 5,000 iterations for each potential regulatory level, and the
variability in the total mitigation costs was examined. The results of the analysis are shown in
Table 10-19. This table shows the lower- and upper-bound estimates (5th and 95th percentiles
respectively) of the Monte Carlo runs, rather than the confidence limits on the mean values, and
reflects the variability in the input parameters, rather than uncertainty.
September, 1999 - Draft Document
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Table 10-19. Distribution of Radon Mitigation Cost Estimates from
Monte Carlo Analysis, SMHlions per Year
Estimate
——
Lower-Bound (5th Percentile)
Central Tendency (Deterministic)
Simulation Mean
Upper-Bound (95th Percentile)
Regulatory Level, pCi/1
100
HHMBHBIH
754
808
851
975
300
•^•••^•i
385
399
417
457
500
^••••MHMM
234
249
259
291
700
: 167
, 177
i 184
1 205
1,000
116
122
126
139
2,000
56.9
61.1
61.4
66.4
4,000
•^^•i^HHM
32.9
34.5
35.1
37.6
At each radon level, the mean costs estimated by the Monte Carlo model is slightly greater
than the corresponding central tendency estimates. At a radon level of 4,000 pCi/1, the mean
modeled radon mitigation cost is $35.1 million per year, about 1.5 percent higher than the central
tendency estimate of $34.5 million. At 300 pCi/1 the mean modeled cost is $417 million per year,
4 5 percent above the central tendency estimate of $399.1 million. Corresponding small
differences are seen at the other potential regulatory levels. These differences arise because the
mean values of the input distributions to the Monte Carlo model differ slightly from the point
estimates of the same parameters that were used to derive the central tendency estimates.
The breadth of the variability distributions differ across the different radon levels. The 5th
and 95th percentile estimates of radon mitigation costs at the 300 pCi/1 level differ from one
another by approximately $72 million per year ($385 to $457 million), which corresponds to
approximately 18 percent of the central tendency estimate. The 5th and 95th percentile estimates
of mitigation costs at 4,000 pCi/1 differ by about $4.7 million, which is about 14 percent of the
central tendency cost estimate. The corresponding ranges for the other potential regulatory levels
fall in between these two ranges.
The distributions of radon mitigation costs generated by the sensitivity analysis are quite
narrow, considering the numbers of inputs that were analyzed,: and the magnitude of the variability
in the individual inputs. The results of the analysis are highly dependent on the assumption that
all the input variables are independent. If this is not the case, then variability in total mitigation
costs may have been underestimated.
10.8.4 Relative Contributions of Model Inputs to Mitigation Cost Variability
In addition to evaluating the overall variability in mitigation cost estimates, the impacts of
individual input variables on the variability in mitigation costs were also evaluated. The Monte
Carlo model was run for systems in the smallest (25-100 people) and largest (lOOK-1 million
people) systems for radon levels of 300 PCi/l and 4,000 pCi/1.; The contribution of the variability
September, 1999 - Draft Document
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of each input to the total variance in the output mitigation costs were measured, and the results are
summarized in Table 10-20.
It can be seen from Table 10-20 that, for both system sizes and radon levels, unit cost
variables contribute a large proportion of the total variance in mitigation costs. For the smallest
systems, approximately 85 percent of the total variance in mitigation costs at a radon level of 300
pCi/1 can be attributed to variability in the unit costs of the common mitigation technologies. The
three aeration technologies (SSPTA/MSBA/STA, HSPTA/MSBA/STA, and PTA/MSBA/STA)
account for 68 percent of the variance, followed by GAC unit costs (14.8 percent), and then by
another aeration technology (PTA/MSBA/STA, 12 percent of variance). The only other inputs
that contribute more than 0.1 percent to total cost variance are variability in the total number of
systems in the category (11.8 percent), variability in the flow rate coefficients (3.2 percent), and
variability in the proportion of sites above 300 pCi/1 (0.2 percent). The small contribution of the
last variable suggests that variability in radon occurrence, which determines the proportion of
sources above the radon level, is not a big factor determining costs for the smallest systems at a
regulatory level of 300 pCi/1.
For the largest systems, unit costs contribute an even larger proportion of the cost variance
at the regulatory level of 300 pCi/1. Three aeration technologies, PTA/MSBA/STA,
HSPTA/MSBA/STA, and SSPTA/MSBA/STA, account for approximately 97 percent of the
variance. The remainder is accounted for by the flow rate coefficients in the cost model.
i
At a radon level of 4,000 pCi/1, variation in unit costs still account for the majority of total
cost variance for the smallest systems, but other inputs contribute significantly as well.
Variability in the unit costs of aeration (SSPTA/MSBA/STA) contribute about 45 percent of the
variance, followed by variability in the estimated proportion of systems and sources above 4,000
pCi/1. Variability in the total numbers of systems contributes just over 11 percent of the
mitigation cost variance, followed by the unit costs of four more mitigation technologies, and a
very small contribution from the flow rate coefficients. The relatively large impact of the
variability in the numbers of sources above 4,000 on total variance is due to the facts that (1) the
relative magnitude of this variability is far greater than it is for a regulatory level of 300 pCi/1 and
(2) the average mitigation cost per source is generally lower at 4000 pCi/1 than at 300 pCi/1.
September, 1999 - Draft Document
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Table 10-20. Contributions to Variance in Tol
300 pCi/L MCL
Small Systems (25- 100)
Cost Element
SSPTA/MSBA/
STA'
HSPTA/MSBA
/STA
GAC
PTA/MSBA/S
TA
Total Number
of Systems
DBA
Flow Rate
Coefficients
Proportion of
Systems and
Sources > 300
pCi/L
Proportion
of Variance
33.5%
22.8%
14.8%
12.0%
11.8%
2.5%
2.3%
0.2%
Large Systems (100K-1
million)
Cost Element
PTA/MSBA/ST
A
HSPTA/MSBA/
STA
SSPTA/MSBA/S
TA
Flow Rate
Coefficients
NA i
NA
NA
NA
Proportio
n of
Variance
53.8%
35.8%
7.2%
3.2%
NA
NA
NA
NA
tal Costs by Radon Mitigation Cost Variables
1 4000 pCi/L MCL
Small Systems (25-100)
Cost Element .
SSPTA/MSBA/S
TA
Proportion of
Systems and
Source > 4.000
pCi/L
Total Number of
Systems
PTA/MSBA/ST
A
GAC
DBA
HSPTA/MSBA/
STA
Flow Rate
Coefficients
Proporti
on of
Variance
44.9%
31.7%
11.2%
4.3%
3.5%
2.7%
1.6%
0.1%
Large Systems (100K-1
million)
Cost Element
PTA/MSBA/STA
HSPTA/MSBA/ST
A
SSPTA/MSBA/ST
A
Flow Rate
Coefficients
Proportion of
Systems and Sites
> 4,000 pCi/L
NA
NA
NA
Proportio
n of
Variance
45.9%
38.8%
10.2%
4.8%
0.3%
NA
NA
NA
1 Unit cost of technologies: SSPTA/MSBA/STA = small-system packed tower aeration, multiple stage bubble aeration, shallow
tray aeration- HSPTA/MSBA/STA = high-side packed tower aeration, multiple stage bubble aeration, shallow tray aeration;
PTA/MSBA/STA = packed tower aeration, multiple stage bubble aeration, shallow tray aeration; DBA = diffused bubble aeration;
GAC = granular activated carbon.
For the largest systems, unit costs again contribute the bulk of the variance in total
mitigation costs at the radon level of 4,000 pCi/1. The same three aeration technologies that
dominated cost variance for this size system at 300 pCi/1 contribute just over 94 percent of the
mitigation cost variance at 4,000 pCi/1. Variability in the flow rate coefficients and the
proportions of sources and systems above the regulatory limit Ithen account for the rest of the
variance.
The relatively high impact of unit costs on total mitigation costs is not surprising. Unit
costs, after all, are incurred by all systems that need to mitigate water radon levels. In addition,
the le'vel of variability in unit costs is quite high, with case studies of similar size systems
September, 1999 - Draft Document
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differing by over an order of magnitude in estimated mitigation costs. The relative low impact of
other factors, such as the estimated proportions of sources and systems above regulatory limits, is
an interesting result, in that EPA's analysis of radon occurrence (USEPA 1999C) indicates that
radon levels in individual sources and systems may be quite high. The reason why this high
variability does not have more impact on national mitigation costs is that (averaged over the entire
universe of groundwater sources and systems) the variability in the radon level has only a
relatively small impact on the total numbers of source and systems out of compliance in any single
year. (Another way of saying this is that the estimated annual average numbers of sources and
systems out of compliance is quite stable, with relatively low variability.)
September, 1999 - Draft Document
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-------
References
Davis, RMS and JE Watson Jr. "The Influence of Radium Concentration in Surrounding Rock on
' Radon Concentration in Ground Water," University of North Carolina, Chapel Hill: March
13,1989.
Longtin, J.P. "Occurrence of Radon, Radium, and Uranium in Groundwater." Journal of the
American Water Works Association. July, 1987.
Marcinowski, F. and S. Napolitano. "Reducing the Risks from Radon." Air and Waste, Vol. 43,
955-962, 1993.
NAS. 1999. "Risk Assessment of Radon in Drinking Water," National Academy Press:
Washington, DC.
NAS. 1998 A. "Health Effects of Exposure to Radon - BEIR VI (Pre-Publication Copy)," National
Academy Press: Washington, DC.
US EPA. 1999A. "Drinking Water Baseline Handbook (Draft).; Office of Ground Water and
Drinking Water, February 24.
US EPA. 1999B. "Guidelines for Preparing Economic Analyses - Review Draft," Office of
Policy, November.
US EPA. 1999C. "Methods, Occurrence, and Monitoring Document for Radon," Office of
Ground Water and Drinking Water, August.
US EPA. 1999D. "Point Estimate of Radon Unit Risks," Memo to Mike Osinski from Nancy
Chiu, Office of Science and Technology, January 22.
US EPA. 1999E. "Radon in Drinking Water Health Risk Reduction and Cost Analysis:
Appendices," Office of Ground Water and Drinking Water, February.
US EPA. 1998A. "Cost Evaluation of Small System Compliance Options: Point-of-Use and
Point-of-Entry Treatment Units," Office of Ground Water and Drinking Water.
US EPA. 1998B. "Cost of Lung Cancer (Draft)," Office of Ground Water and Drinking Water,
October.
US EPA. 1998C. "Cost of Stomach Cancer (Draft)," Office of Ground Water and Drinking Water,
October.
September, 1999 - Draft Document -143-
-------
US EPA. 1998D. "Evaluation of Full-Scale Treatment Technologies at Small Drinking Water
Systems: Summary of Available Cost and Performance Data," Office of Ground Water
and Drinking Water, December.
US EPA. 1998F. "'Health Risks from Low-Level Environmental Exposure to Radionuclides,"
Office of Radiation and Indoor Air, Federal Guidance Report No. 13, Part I - Interim
Version, EPA 40l/R-97-014.
US EPA. 1998G. "Model Systems Report (Draft)," Office of Ground Water and Drinking Water,
March.
US EPA. 1998H. "National-Level Affordability Criteria Under the 1996 Amendments to the Safe
Drinking Water Act," Office of Ground Water and Drinking Water, August 19.
US EPA. 19981. "National Primary Drinking Water Regulations: Disinfectants and Disinfection
Byproducts; Final Rule," 63 FR No. 241, 69390-69476, December 16.
US EPA. 1998J. "Potential Benefits of the Ground Water Rule - Draft Final Report," Office of
Ground Water and Drinking Water, February.
' :l
,|
US EPA. 1998K. "Radon Cost Estimate," Memo to Bill Labiosa from H. McCarty, Office of
Ground Water and Drinking Water, December 4.
US EPA. 1998L. "Re-Evaluation of Radon Occurrence in Ground Water Supplies in the United
States - External Review Draft," Office of Ground Water and Drinking Water, September
30.
' I
US EPA. 1998M. "Regulatory Impact Analysis of the Stage I Disinfectants/Disinfection By-
Products Rule," Office of Ground Water and Drinking Water, November 12.
US EPA. 1998N. Safe Drinking Water Suite Model. Inputs from Version 3.4 of the Cost Library
and Version 4.0 of the What If Module.
'I
US EPA. 1998O, "Technologies and Costs for the Removal of Radon From Drinking Water,"
Office of Ground Water and Drinking Water, September.
US EPA 1997A. "Community Water System Survey. Volume II: Detailed Survey Result Table
and Methodology Report." Office of Ground Water and Drinking Water. EPA 815-R-97-
00 Ib, January.
US EPA. 1997B. "Withdrawal of the Proposed NPDWR for Radon-222," 62 FR No. 151,42221 -
42222, August 6.
September, 1999 - Draft Document
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US EPA. 1995. "Uncertainty Analysis of Risks Associated with Radon Exposures in Drinking
Water," Office of Science and Technology, Office of Policy, March.
US EPA. 1994A. "A Citizen's Guide to Radon (Second Edition): The.Guide To Protecting
Yourself and Your Family from Radon," Office of Radiation and Indoor Air. EPA-402-
K92-001, September.
US EPA. 1994B. "Final Draft for the Drinking Water Criteria Document on Radon," Office of
Water, September 30.
US EPA. 1994C. "Report to the United States Congress on Radon in Drinking Water, Multimedia
Risk and Cost Assessment of Radon," Office of Water. EP A-811 -R-94-001.
US EPA. 1993 A. "EPA's Map of Radon Zones: National Summary," Office of Air and Radiation,
EPA 402-R-93-071, September.
US EPA. 1993B. "Uncertainty Analysis of Risk Associated with Exposures to Radon in Drinking
Water," Office of Science and Technology, April 30.
US EPA. 1992 A. "National Residential Radon Survey: Summary Report," Office of Air and
Radiation, EPA 402-R-92-011, October.
US EPA. 1992B. "Technical Support Document for the 1992 Citizen's Guide to Radon," Office
of Air and Radiation. EPA 400-R-92-011.
US EPA. 1991. "National Primary Drinking Water Regulations: Radionuclides: Notice of
Proposed Rulemaking," 56 FR No. 138, 33050-33127, July 18.
US EPA. 1989. "Analysis of Potential Radon Emissions from Water Treatment Plants Using the
MINEDOSE Code," Memo to Greg'Helms from Marc Parrotta, Office of Ground Water
and Drinking Water.
US EPA. 1988. "Preliminary Risk Assessment for Radon Emissions from Drinking Water
Treatment Facilities," Memo to Stephen Clark from Warren Peters and Chris Nelson,
Office of Water.
Viscusi, WK, WA 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.
September, 1999 - Draft Document -145-
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-------
APPENDIX A. Equations and Parameter Values Used in the Assessment of
Risks and Risk Reduction Benefits
-------
. li'llPI' '! IP '
-------
APPENDIX A. EQUATIONS AND PARAMETER VALUES USED IN THE
ASSESSMENT OF RISKS AND RISK REDUCTION BENEFITS
This appendix describes the methods that were used to estimate the risks associated with
radon exposure from domestic water supplies, the risk reduction associated with regulatory limits
on radon levels in water, and the monetary benefits associated with the reductions in risk. As
noted in Section 3, the benefits of reductions in radon exposure take the form of reduced cancer
risks. To estimate benefits, it is necessary first to estimate individual risks to those exposed to
radon in domestic water, then to extrapolate these risks to exposed populations (estimate
population risks) and, finally, to associate each type of outcome (fatal and non-fatal cancer) with
monetary surrogates. The following discussion explains how the "nominal" risk estimates
(central tendency values based on point estimates of input variables) were derived. The nominal
estimates of risk and risk reduction were used throughout the RIA as the basis for benefit
estimates and cost-benefit comparisons.
i
A.I Individual Risks \
A.I.I Individual Risks for the General Population
Individual risks of fatal cancer associated with radon exposure to the general population
were calculated as described in Section 3.2, using models and input parameters developed by
EPA(USEPA 1999A,B) and the National Academy of Sciences (1999). EPA's analysis resulted
in the following estimates of radon-associated cancer risks per pCi/1 (Unit Risks) for each
exposure pathway.
Table A.l-1. Summary of EPA/NAS Unit Risk Estimates
Exposure Pathway
Inhalation of radon progeny1
Ingestion of radon1
Inhalation of radon gas2
Total
Lifetime Cancer Unit Risk per
pCi/1 in Water
5.9X10"7
7.0X1 0-8
6.3 X 10-" i
6.7xi Q-7 ;
Proportion of Total Risk
(Percent)
88
11
1
100
1. Source: NAS 1999.
2. Source: Calculated by EPA (1999A,B) from radiation dosimetry data and risk coefficients provided by NAS
(NAS 1999).
-------
These unit risk values were used by EPA to develop their "nominal" point estimates of
baseline individual risk, and to estimate population risks as discussed in Section A.2. The
nominal risk calculation is illustrated for the baseline case (no radon regulatory limit) in Table
A.l-2.
Table A.l-2. Individual Risk Calculation for General Population, Baseline Case
Input
Parameter
Lifetime Unit
Risk (per pCi/L)
Annual Unit
Risk (per pCi/L)
Mean Radon in
Water, pCi/1
Mean Annual
Individual Risk
Lifetime
Average
Individual Risk
Exposure Pathway
Inhalation of
Progeny
5.9X1 O'7
7.92X1 O'9
213
1.7X10"6
L26X10'4
Ingestion
7.0X1 0"8
9.39X10'10
213
2.0X1 0'7
1.50X10'5
Inhalation of
Radon Gas
6.4X1 0'9
8.47XKT11
213
1.8X10'8
1.35XKT6
Total
6.7XKT7
8.93X10'9
213
1.9X10'6
1.42X1Q-4
These risks are calculated as:
= Unit Risk
Pathway
Average Radon
(A.l-1)
where:
IRPathway
Unit Risk,
•Pathway
Individual risk (lifetime or annual) of fatal cancer from the
indicated pathway
The unit risk of fatal cancer from that pathway (cancers per
pCi/1, annual or lifetime)
Population-weighted average radon level (pCi/1)
Average Radon =
A. 1.2 Individual Risk Reduction for the General Population
Reductions in individual risks associated with regulatory limits on radon exposures were
calculated by subtracting the residual risks associated with the regulatory limits from the risks
under the baseline case. Residual risks under the various radon levels were calculated using
equation A.l-1, and the population-weighted average radon levels calculated for each radon level.
Reductions in radon levels were calculated as described in Section 3.4, and the estimated average
-------
residual radon exposures for radon levels of 4,000 pCi/1 and 300 pCi/1 are given in Table A. 1-4.
The average exposures are considerably less than the radon exposure limits because the average
radon exposure limit was far below 4,000 pCi/1 even without a radon regulatory limit, and when
systems comply with the regulation, they often select technologies that reduce radon to levels
below the regulatory limits.
Table A.l-4. Average Radon Levels Associated with
Radon Regulatory Limits, pCi/1
System Size
Very Very Small
Very Small
Small
Medium
Large
All
Radon Regulatory Limit
Baseline Case
570
531
242
176
188
213
Limit = 4,000
pCi/1
532
486
237
176 \
187
210
Limit = 300
pCi/1
163
153
125
131
136
134
A.1.3 Individual Risk Estimates for Smokers and Non-Smokers
As discussed in Section 3.2, EPA calculated risks separately for smokers and non-
smokers. This was done because smokers are known to be more sensitive to inhalation exposures
to radon progeny than non-smokers. To perform this calculation, EPA used estimates of cancer
Unit Risks derived for "ever-smokers" and "never-smokers" by the NAS (USEPA 1999B). The
calculations of individual risks, which are again performed using equation A. 1-1, are summarized
in Table A. 1-5. '•
-------
Table A.l-5. Individual Risk Calculations for Ever- and Never-Smokers
Input Parameter
Lifetime Unit Risk
(perpCi/L)
Annual Unit Risk
(per pCi/L)
Mean Radon in
Water, pCi/1
Mean Annual
Individual Risk
Lifetime Average
Individual Risk
Population
Ever-Smokers
9.63X1 0'7
1.3 1X1 0'8
213
2.74X1 O'6
2.05X1 0'4
Never-Smokers
1.85X10'7
2.43X1 O'9
213
5.26X1 0'7
3.94X1 0'5
A.2 Population Risks
' .: , ' ' ' ' i
A.2.1 Population Risk of Fatal Cancers
",; :'! . ,; |
The central tendency estimates of population risks associated with exposures under
baseline conditions and at different radon levels were obtained by multiplying the individual risks,
derived as described above, by the estimated exposed populations:
~ IRsi:
;ize
POPs
(A.2-1)
where:
P°P
size
i
Population risk (fatal cancers per year) for system size category
= Individual risk for system size category
= Population obtaining water from systems in size category
The populations exposed hi each system size category were taken from EPA's Water
Industry Baseline Handbook (USEPA 1.999C), and are shown in Table A.2-1. These estimates
were derived from analyses of data from the Safe Drinking Water Information System (SDWIS).
-------
Table A.2-1. Populations Exposed to Radon from
Community Groundwater Systems
System Size
Very Very Small (25- 100)
Very Small (101-500)
Small (501-3,300)
Medium (3,301- 10,000)
Large/Very Large (> 10,000)
Population Exposed in
Households
•868,152
3,747,450
14,125,825
14,274,415
55,045,735
1 population risks of fatal cancer were then estimated by summing
the pop
across all the system size categories.
A.2.2 Population Risks of Non-Fatal Cancers
Non-fatal cancer incidence was estimated from the fatal population cancer incidence based
the proportions of cancers due to each exposure pathway and the estimated mortality of each type
of cancer. As shown in Table 3-4, inhalation of radon progeny were found to be associated with
approximately 88 percent of the total radon-related population fatal cancer risk, ingestion of radon
was found to be associated with 10 percent of radon-related fatal cancer, and inhalation of radon
gas was found to cause an estimated 1 percent of the all cancers from radon in domestic water
supplies:
PR
•Progeny
PR
•Ingestion
0.885 *
0.101 *
0.009 *
PRTotal
PR-Total
PR-Total
(A.2-2)
(A.2-3)
(A.2-4)
where:
pRTota, = Total population cancer risk (fatal cancers per year)
PRpro en = Total population fatal cancer risk due to progeny inhalation (fatal
cancers per year)
pRln estion = Total population fatal cancer risk due to'ingestion of radon (fatal
cancers per year)
pRGas = Total fatal cancer risk due to radon gas inhalation (fatal cancers per
year) :
These calculations were performed for the general population and for ever- and never-
smokers, using the individual risk results shown in Tables A. 1-2 and A. 1-5.
-------
The incidence of non-fatal cancer for each pathway was then estimated on an organ-
specific basis:
NF0rgan = PRPathway * POrgan * (1 - M0rgan)
(A.2-5)
where:
NFOrgan
PR-
-Pathway
organ
i
Non-fatal cancer risk for organ system (cases per year)
Population fatal cancer risk for the pathway (fatal cancers per year)
Proportion of cancers from the pathway occurring in the organ
system
Mortality rate for cancer of the organ system
The proportions of cancers of the various organ systems due to each exposure pathway,
along with the estimated mortality rates for each cancer, are given in Table A.2-2. The total
numbers of non-fatal cancers per year were then summed across the exposure pathways and
System sizes for the baseline case and for the various radon levels.
Table A.2-2. Proportion of Fatal Cancers by Exposure Pathway and
Estimated Mortality
Exposure Pathway
Inhalation of progeny, radon gas
Ingestion of radon gas
Organ Affected
Lung
Stomach
Colon
Liver
Lung
General Tissue
Proportion of Fatal
Cancers by Organ and
Exposure Pathway
( percent*)'
89
9.5
0.4
0.3
0.2
0.5
Mortality
(percent)2
95
90
55
95
95
—
—_ _ _ -_.__^ ___ _— «V»»»WM^ uubu. uiiv* Vt ^t*ii JL/^Vrfl JL It- t 1OIV \*\J
2. Source: US EPA analysis of National Cancer Institute mortality data.
-------
A.3 Population Risk Reduction
Reductions in population risks were calculated by subtracting the residual population risks
under different radon levels from the population risks under baseline conditions (no regulatory
limit). The resulting differences represent the risk reduction benefits associated with the radon
levels. The population risk reduction estimates are summarized for the various radon levels in
Table A.3-1. !
Table A.3-1. Summary of Central Tendency Population Risk Reduction Estimates
Radon
Level
(pCi/1)
(Baseline)
4,000
2,000
1,000
700
500
300
100
Residual Fatal
Cancer Risk
(Cases per
Year)
168
165
160
150
141
130
106
46.8
Residual Non-
Fatal Cancer Risk
(Cases per Year)
9.7
9.5
9.4
8.8
8.3
7.6
6.1
2.8
Risk Reduction
(Fatal Cancers
Avoided per Year)1
0
2.9
7;3
17.8
26.1
37.6
62.0
120
Risk Reduction
(Non-Fatal Cancers
Avoided per Year)1
0
0.2
0.4
1.1
1.5
2.2
3.6
7.0
Notes:
1. Risk reductions and residual risk estimates are slightly inconsistent due to rounding.
-------
A.4. Monetary Benefits
i
The approaches used to develop monetary surrogates for fatal and non-fatal cancers are
discussed in detail in Section 6.2 of the RIA. The values of the monetary surrogates used to
estimate monetary benefits are summarized in Table A.4-1.
- . „ |
Table A.4-1. Values of Monetary Surrogates Used in the Calculation of
Health Benefits (SMillions, 1997)
Health
Outcome
Fatal Cancer
Case
Non-Fatal
Cancer Case
Monetary
Surrogate
Value of
Statistical Life
(VSL)
Willingness to
Pay to Avoid
Non-Fatal
Cancer (WTP)
Central
Tendency
Estimate
5.8
0.536
Lower-Bound
Estimate
0.7
0.169
Upper-Bound
Estimate
16.3
1.05
For the baseline case and for each radon level, costs associated with fatal and non-fatal
cancer cases were calculated:
Costs
'Fatal
= PR-
-Total
VSL
Costs,
'Non-Fatal
NF
Total
WTP
(A.4-1)
(A.4-2)
where:
CostsN
on_Fatal
The total health costs of fatal cancers ($ per year)
The total health costs of non-fatal cancers ($ per year)
PRTotai = Total fatal cancers per year due to radon in domestic water
N^Tota! = Total non-fatal cancers per year due to radon in domestic water
The total benefits at each radon level were then calculated by subtracting the costs
associated with the radon level from the baseline health costs.
-------
A.5. References
NAS. 1999. "Risk Assessment of Radon in Drinking Water," National Academy Press:
Washington, DC.
USEPA. 1999A. "Point Estimate of Radon Unit Risks (III)," Memorandum from Nancy Chiu,
Office of Science and Technology, to Mike Osinski, Office of Groundwater and Drinking
Water, February 19.
USEPA. 1999B. "Draft Criteria Document for Radon in Drinking Water," Office of Science and
Technology, June.
USEPA. 1999C. "Uncertainty Analysis for the Risks Associated With Radon in Drinking Water,"
Office of Ground Water and Drinking Water.
USEPA. 1999D. "Drinking Water Baseline Handbook (Draft),"' Office of Ground Water and
Drinking Water, February 24.
-------
-------
APPENDIX B. Cost Curves for Radon Reduction and Disinfection
Technologies
-------
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-------
APPENDIX C. Flow Estimation Equations for Public and Private
Water Systems
-------
-------
Flow Rate Formula*
= (a) x (population / 1000) A (b)
Average Daily Flow (AF) Coefficients
Public Water Systems
Private Water Systems
a =
0.1284
a =
0.1029
b =
1.0584
1.0628
Design Flow (DF) Coefficients
Public Water Systems
Private Water Systems
a =
0.4041
a =
0.3179
0.9554
b =
0.9608
* Flow Rate is in Million Gallons per Day (MOD)
-------
-------
APPENDIX D. Summary Cost Tables
-------
r'l '••: !(•! It;:
11 It., if |
-------
10OMCL
Public Witor Systttns
CoelteMonllore
sue »
Symn.II,. NO.OISUO
•M14M 0053-4
Mrl-WO* 4247 1
XM1-W4M SBS3.4
KXM1.09.OM 49855
fM81.1M.OM 11639
lyotomllTi OoMCo*
29-10S < 3.900.526
MjllTM 17522508
M1.16M 10586.691
•M135M 29.880.613
OMD148.M8 52.054.595
5BuM1-1M.tM 18575.580
SyolejftSb. 06MCO«
2>,ieo 3,609528
igilM 17,622.306
Mt-1O6O 10,686.891
S5tn-16uM> 35.456.378
•MM-M.OM 52.054.595
MuM1.tt6.M6 18.975,580
lleonHnMCooH „
9voMnSU. 0>MCo*
20VM* 3.609.526
tgUH 17.822506
lol-MM 10.680.691
3.301-tt.OM 35,458578
IfUol-oUM 52.054595
MjM1-tt9;M6 18.975.580
2f,tt6 81.000
ttMOO 93.000
Ut-ttM 97.000
1M1-35M 82.000
3J01.14>M 87.000
MJM1-OUM 108.000
I8JM1.1M.9M 122.000
tto.M1-t.MUM 127.000
Frequency of
koaoringporrooT
NevotSyoNone
1202
4104
2574
3792
997
113
52
AmuelCioCo*
4.791.823
27228.453
18.043.600
44296.854
9S.490.029
2)547.181
1 313805.749
ArxuolCjpCo*
4.791.826
27228.453
16.043.800
44.296.654
63591.976
95.480029
26547.181
AtmuotCapCe*
S 4.791.828
S 27226.453
S 16.043500
I 44.296.854
t 63.991.976
J 95.480.029
S 28547.10!
MonoorlngCO* ceotpersyolom
302.904 252
1210.680 295
849.420 330
1.403.960 300
997.000 1.000
232.780 2580
136240 2.620
Aiou* Monitoring"
CopCO* Co*
SO784.894 S 302.904
288.437.434 1210.680
169.988250 849.420
469.302.093 1.440560
677.331507 1,170676
1.011.516.788 997.0M
302.42924! 232.780
~ Mm*ermgroitr"
No.ofSMeAbeve Sy*e»» Above
RO^UHI Heg.Um«
1237 249.542
4.625 931.345
2.795 574.080
4.969 1.039.195
4.149 e4i.7JU
3583 810.452
'832 180225
01, 11O748
Monitoring Co* for
Syslonv Above Reg. AvoregoDoMynoM
Una (MOO)
249542 O0071
931.345 0.0349
574.080 0.0947
1.036.198 O25O3
682.730 0825!
610.452 3.204B
189225 11-1711
S 110.746 37.59M
SyetOMSUe NO.OISOM
WS IW9
VS 114519
S 5853.4
M 8148.9
L »I2
8.904256 WS
46,259.442 VS
27581511 S
73520.427 M
146531.824 toM
47.755541
58545.789
No.ofSye.Aoevo Co*por
990 8.938
3.157 14584
1.740 15.697
Z732 27.531
610 183.040
92 519.416
42 S 1.379.899
HH
Roo,Urot Co*
990 276.79
1157 107.13
1.740 4405
Z732 24.70
810 16.90
92 1554
42 1277
HewofSyHone MoMorlngCo* Co*lot6y*o«.
3308.0 1513.584 285
6366.0 1290380 389
1918.0 1,170.676 611
11100 1229.780 1.10.
52.0 136240 1620
5 °2re31.634 J 31018:261 S 339201127 1513.584
$ 40.589.304 I 80541655 > 639270543 129O38O
t 39.458.378 S 83.991,976 > 677.931537 1.170.878
S 71.030175 S 124.027210 S 1513548.029 1229.780
1 24.703922 S 33505.627 S 354.969.000 138.240
SyeteoiSbe OIMCe* Aonel Oo Co* Rog,Un*
WS S 21.631.834 t 31018281 5582
VS 1 40589.304 S 90541855 7.785
S I 38X466.376 I 63591.979 4.149
M » 71.030175 J 124J07210 4393
L I 24703922 S 33505.627 497
1 MoMtoringCo*for
SyoMme Above Reg,
SMtomSIze OAMCo* AjmuolCapCo* Untt
WS S 21.631.834 31018281 I.19O867
VS 1 40596504 6054t«SS 1512256
S » 35.458576 63591.978 881730
M J 71.030.175 124,027210 999.677
1 S 24703922 33.505.627 11O748
S 35.161699
S 1O32O2.339
) 100.821.028
S 196287.185
S 59.345,789
SvoMneAbovollog, AboveReg, Co*por
UMI Unot Sy*«.
1.171360 4.147.3 » 13219
1557.057 4,471.7 > 22513
829.773 1.444.7 $ 69.411
878593 9013 > 217.150
97578 413 S 1.379,363
Averege Deny Flow AfletM moment*
(MOO) SyoMne Co*
00281 4,147.3 S 11652
0.1899 4.471.7 S 29.08
05252 1.444.7 S 20.09
4.0158 902.3 S 1922
37.5902 425 « 1277
Private Waltf Systtfns
Coc« to Monitor • Fraquoncyol
SIM MonHntogpofVO
1 SfMiSb. Mo.o(Sltt. ltaolS,««m MorttottoBC-l
'JS.H»^ 155749 12361 t 3.114.972
•22., 144196 9778 5 ZSB3.920
'^MM 2813.3 1705 1 562.650
£££. 2908.9 .S3,, 5.1.7,0
'MMWOM 12150 243 » 243.0W
tUM-VtMt 247.2 » « *•**
<,MOT.1jOt.||M 1634 14 1 SHS —
STOT.SH. OUICOM MMCvC** ToWCwCo.1
~.*? 37.360788 43.9O1.625 S 466.047.903
«*UM 33.528100 51,701,157 * 547.722.795
SvS.. 6.W079 9.587.10. » 101.585.935
MU5M 1O3S3.413 16.106296 S 170530528
XMtwMJBM 7513.185 13.808,321 S 149.921,186
M'MUMM li^ijoss 2o!936.334 s 221.799519
UMt-WUM 3,448.637 5509,175 I 56234587
ML8>n.tWMM 6407.891 1 6736600 « 92.556.823
T~*r~*<***,
No. efS«M Above
SrtHmSla 08.MCOM A™«4tC»Co« R^Un*
If,*. « 37.380.788 43.991.875 11731
M1.44* 33526.160 51.701.157 11.016
M1-1M8 6286.079 9.S87.108 1.852
1MV3JM 10353.413 16,106296 2.014
U61.M.9M 7.313.185 13.668521 994
1..0.1-M.O.. 11245.083 20938534 868
U.M1.1H.K4 3.445.637 ""S 1M
1H l_UCon. _ M»«toi1ntCo«lor
SystMIM AboM R*g.
l»un.Sllo 0»MCo«« An~»tCi.CO«t U"*
2S.M6I 37.380.788 43591,825 2589.213
1i1ll> 33.S28.190 51.701.157 2218.525
M1-MM 8.288.079 9.587.105 3902S3
•MUJM 10353,413 16,109298 419.188
1501-WIM 7.313.185 13.886521 211.469
WJM1-M.6M 11245.063 2O938534 197.532
«Un.M6.0M 3.448.637 5.308.175 40.169
tMJM1-1.9M.&16 » 6.407.891 i 6.739.800 S 29517
CotfporSyiMm
252
296
33O
360
1.000
2.080
Z620
Monitoring Co*
V14.972
2583.920
582.650
581.780
280.449
243.000
49.440
36.690
Monitoring Co* lor
SyoMRwAbow
Rog-LMI
1589213
2218.525
390253
419.168
197.532
40.189
29.817
AvoragtCMtyFlow
(MOO)
O.OD52
0.0216
O0726
at922
17355
9.1202
36.0777
SvMn.su
WS
VS
s
M
Tout An»u* CO*
t 64.487.386
88.113237
16.435,635
27.041.480
21.481 .935
32,424.417
8.604252
5 15.181.282
Ho. of sy*. Above
llo»UkM
10183
7.520
1.1S2
1.103
196
20
"
Ho.otSv>.AbovI
HoB>Umlt
10.103
7520
1.152
1.103
198
29
11
No. of SUM
29994.5
572Z2
14022
14622
1634
syoMmSte
WS
VS
s
M
Coelpor
SvMn.
1 8243
> 11.62.
14.105
24587
163.917
450.609
> 1.333.372
toomionul
Cool
40154
182.39
46.68
36.43
2O38
16.79
S I2S.
No.ofSy*nw HMIoringCoot Coot pot SyoHn.
22137.0 t 5596.692 » 271
3238.0 > 1.H4.430 » 354
459.0 S 2C0.449 S 811
267.0 S 292.40 S 1.O9S
140 S 36.BB » 2.620
out cm A»»«icioCiioi caoCo* Co*
5 70J06.9W 95502.782 1.011770.698 5.906.692
18.630.49J 25.803.401 272,196211 1.144.430
7513.H1 11896.321 I4632I.18S 28O449
14.691.71!> 28244509 271034.70J 292.440
8.407.991 8,736.800 92556.821 36560
No, of SMO Above
SyoMoSbe 08MCO* AenyolCwCo* RoUJmii
W» » 70908*18 95.802,782 23.74.
VS > 16,639.492 25593,401 3.888
S » 7.313.165 13596.321 994
H S 14.691.719 28244,509 1.045
t. S 6,407.891 &736.690 131
SveHmo Above Reo,
SvoHmSIn OWCo* Ann>olCo>CO* LMI
WS J 7O90S.948 S 95,892,782 4.784.739
VS > 18.C39.402 t 29.693.401 799.420
S J 7.313.165 1 13588521 211.489
M S 14591.719 S 28244.509 237.722
L S 6.407891 S 8.736.690 29.817
I 172500.822
S 43.477.324
$ 21,461535
$ 41228.669
S 1S.181262
UonHoring Co*tor HokOfSye.
SyflMm Above Rog. AbovoMog, Co*por
LM Ur* SvoMn
4,749514 17.703.6 > 9.879
773279 2255X > 19.113
199,782 346,1 » 81.775
200.023 217.0 S 180.573
16217 114 J 1533,056
Avenge °o»FM AfMtol Hcremnul
(MOO) SioMno Co*
00121 17.7039 217.64
0.1311 22SS.4 37.91
06643 346.1 3Z09
35094 217.0 17.08
36,0777 11.4 1156
93.000
110.000
80.000
102.000
124.000
110.000
90.000
114.000
-------
ill ,I'.
XXJMCU
e
Sf*M«4Ul*
B*"'W*
Witt*
'**^*?**
MUMIU.***
•AMim>44
T tTl.Mm.UM
M..HJ3M
jMuftntMMM
.MI M HMNMT •
Mt
>*•.«< MM
ISI4S
•XBJ4
4347 1
73046
40930
tto
IfMLlMa
131 4,311
,^^-JV
7530,153
t *«•*••
t la** *•
finy|"CT4*
ktaM.Mr)n«BWraar
HferfSr****1*
1303
4104
2574
3792
SOT
113
,":!' : • bi'i
AM.MlCapC.MI
1777 35t
8.441.042
21291(123
1I.S6OSOS
11421738
MenMwtrttCW Coat par SyaMn*
301004 1 252
1.210 MO S 295
848.420 3 330
1.440900 t 380
907,000 $ 1.000
232.780 S 1000
13O249 S 1620
CapCMt Coat
29,421383 S 302.804
194511,443 3 1,210.880
80424.S1T S 040.420
24O427.00S S 1.440980
4176QO501 * 987.000
121471151 S 231780
I 141232.973 S 139.240
1 1.514,284904 S 6.340,880
WS
VS
s
M
etriAnmulCoat
SJ78.208
27.011623
14.B04.B73
40.577.055
4O255.641
0143O707
19.623.448
S 23.711554
S 239.7M.619
H*.ofSMra Naw of SyataiM MoraMrlnff Coal Coat par Sratam
7587.9 5306. 1.511584 205
1149)9 9366. 1290.360 300
5853,4 1919 1.170.678 611
9140 9 1 1 10 1.229.7EO 1.108
6912 510 136,2X0 1020
L, • i ,i !
SytumSta* O4>MC«« AmunCapCc*. CtfCo* C«<
WS 1Z499.172 S 18.306.078 HO934.827
VS 21.390.394 s 31.702.0t4 335.052.122
S 18.560.685 > 28£342» 302.1S9.S30
M 29.650.762 S 50.979.613 540478.742
L I0.1SO.SSS S 13.425.758 142232.673
To(4l 90.421.559 S 142.937.791 1.514^84^04
tt TotU
.513.504 3Z286.832
1SX3K 55.3S2.S28
.170.676 41255.041
.229,730 8U60.IS5
138.240 23.712.554
L340.0M 3MJ»4.«1»
p_BOS2 _ .
SM.I4* 9.H9JM9
\ttimt wxnxff
'tn.ttu utun
[tMtiuM " ' itnajni
4.UV44IUM4 2Z030L90S
Wj^tMjM 7^3010
1 !'",
M.M* s zi«>«
M1M* ' » »ft3TJ..37
MVM44 5J 1*111
Wt^UM 13,173.873
fOMIMJ** 2XQ31.99D
M^ti mm 7-Dato
j.l£l>iiii>i|iiiinnii];
M1«M OJ30Q
MVH44 97PC9
hv
1777 JSO
1SJ.M.716
fl,441,OC
212*1.623
3*.4tl,108
11.S8O303
S 11431758
Syi
1777JSO
11528,718
21291033
3B.4tl.108
11.580 509
S 11425.758
730
1831
1.4S5
1.490
348
204
LMl
140.407
578.845
310371
584.721
440632
101928
60.240
S 140,407
» S7084S
S 31O371
S 594.721
J 44OB32
« 101928
1 60240
("00)
00071
O0349
O0047
02505
O8252
12049
11.1710
375602
503
941
758
441
50
Hag. Urn*
503 *
1.955
941
i.sas
751
441
50
23 |
Coal par
O940
11405
15,168
23.387
90.078
14O372
300.154
cfamantal
Coal
289.51
9028
4157
2277
17JS
1198
11.87
952
SyrtamStea OCMCoat
WS 11409.172
VS 21.390384
s io.sao.BW
M 29.050.762
L 10150558
SyttamSlxt OAMCoat
WS 11490172
VS 21.300364
s tosooees
M 29^50.762
L 10150558
AMMMI Cap Coat
S 10308,078
S 31.701084
S 3*524,280
S SO979.613
S 13.425,758
S
Annual Cap Coal
IO309.076
31.701064
2S.524JI80
50.S79.613
13.4T5.758
Mag.LlmH Unll
1591 711120
4.134 628.743
1,948 309.528
1.030 367.640
204 40.729
, i|
yManwAbowRa* Avarago Daily Flow
UmM (MOO)
728.052 0.0282
908.092 O1 920
463.231 O9252
541758 40158
00.240 375002
II
AbowHag.
Umtt
1547.6
1505.8
750.2
490.8
23.0
Alfaetad
1547.6
1505.6
7582
490.8
210
Coal par
SyMam
S 11380
S 21.520
S 59.981
S 105.442
t 1.027,175
tacnmantal
Coal
10824
28.95
17.35
1138
9.52
eaJjna-AJii;
Syv-MAU
KsttM
Mt«M
8*1^ MM
I-MHUX3J*
»M*t4.U**
HLMI^IfOM
f*££*M>**..*
L»r*"B
JM.14.W
M^*M*
9MMLM8
U-M^MUM
«M*MiJM«
MjM«^1*M«*
P^*»1-^»
rga***
' '"'' *' «
«• HsKMlSMM
1S874H
144IR8
2AI13
2808.*
title
2472
M 18S4
m M«C4«t
21.ttt.5TO
I».3«.a33
U48J88
isotoo
3,4t 4J83
4,ro.«a
t.423.0CO
»• » S833.W
H«..ilSrit.*n.i UwiterintCMl
t2»t 3.1!4.9n
9778 2,8e3j9QO
I7W S3Z8SO
1S31 581.780
498 280.448
243 243.000
34 40,440
14 S 30,660
AMMriOpCMt A««»*C*.>C**t
25.830529 271^30158
20.983.149 317.941,812
SjeOUOt 53JS4J72
8.488J23 88,807,638
OinUW 85.482.413
2.15.L2»4 2Z801.430
1,502.233 * 37.10J704
CQ«p~Sr+«m
252
295
330
380
811
1.000
Z080
1020
MM*arinaCo.*
3.114.972
2.8C3.C20
582.050
381.780
20O449
4».440
1 38.090
SyMmStia
WS
VS
S
M
(.
oWAnMUlCo.it
SO.365.089
SZ280002
0.835.772
14A50.844
9^74.400
1824.733
8.171 .900
N*.efSllM Ho.o(SyaNm« MonNoring dm COM pw Sjntam
296045 22137.0 $ &098.S92 271
572U 3230.0 $ 1.144.430 354
140Z2 450.0 S 280.449 611
14SZ2 287.0 S 292.440 1.095
1834 14.0 S 30.EBO 1620
1
SyMvnSte OtMCoM Annual Cap Cort CapCoM Co
WS 41.011202 S 53,811860 500.171^171
VS 8,740,338 S 13.403.659 141962.012
S 1414,052 S 8.179.169 05.461413
M 0188,684 $ 10007.502 114.406,788
•t TOM
5JW9.B02 100.825,760
t.144,430 21389.419
280440 9.674.400
202.440 17269.897
38.690 6,171,900
WttUM
UttMM*
HtttMtM
mtn-imm
CAM Cart
21J191S70
iatnao
3.414,«a
4 TO 000
I.42XKO
6.41
(.tntus
•X03K2M
Z15Z2M
ftofl-UnH
7516
6.7«
1,061
487
1.530,451
1J73007
2M.5SS
240.115
110.972
107.444
21.660
16.21S
6.007
4.SS9
1S2
107
8,002
10.899
13.610
22.457
53.435
125,0*1
339.977
903.735
41.013£02
S.74SJ2S
3.414.552
11B8.M4
2S32.907
S3.913.gM
I3.490.esa
&179.IM
10.W7.592
3.SQ2.233
MtbofSMwJUmv*
Ita^UmH
14202
2.045
4S7
437
AbovwRcg.
UmN
ZSSZ33S
400.005
93.31S
(7.42S
10.98S
JU)ovtR4«.
Umtt
10.753.3 S
1.254,9 S
181.B S
11S.1 S
B.2 S
9.251
10.050
53.337
144.093
902.S87
MOtt.4jl.MM.!
IUJJlta
3O4SJ9S
5J01041
X4t<8»
25.01S2S
21,983.140
5.026.S3S
2.1SUM
IKa™
UnM
I.53S.4S1
IJ73.807
205,588
240.115
110.972 '
107.444
21^60
'«.3H
Avw*9*04.T7n*w N4he4Syt.Akow
(MOO) IU»Lm«
00052 6.097
0.0216 4.656
O.OT2S
0.1B22
a6543
2.7355
9.1302
3607T7
182
107
15221
4521
32.70
2775
15.S3
12S3
9.38
SyMmSln
WS
VS
OAMCoct AfMU4IC4pC««t
41.013^02 S 55.613.808
S.740.32S > 13,403.859
3.414.652 > 6.179.189
0.1M.M4 J 10.607.592
Z63Z9B7 t 3.502^n
LMl
Z910.05S
445,703
110.972
129.305
18318
AvmglUJIynm AIMcM HamMit
a«23
ai326
0.8543
3.3D94
39.0777
tO.753.3
1JM9
181.6
CMI
206.12
27,75
13.00
938.
(10,030
88,000
KtlSCO
134.000
i to ooo
-------
stats MCL
SnMn.511. MkoUHt. »o.olSra»a«»
—. .M 15145 1202
•MM 90S34 4104
••-MM 4247 1 ^^
»jajn-in8 7204.8 3732
«•«*•» So '»
•U6M6.0M 4983.0 ~'
-rrjr~ '=> «
%—- -",5-,. — «S5,
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iT,.,, 3.437.829 S2SJ242
Siii,, 10.036544 14.612298
\Zu*nJHX» nnaa 20,719.70
SS,.1».00. 4.086.386 M£.7»
SSI1"" S 52.788.096 S 82.4n.758
Monitoring Cort
30Z904 «
1.210.880
940.420
1.440.980
997.000
23Z780
138.240
Cap Co*
3.254.525
117.4Z3.177
55.970.745
1S4.t02.8M
168.426580
219509.457
63549518
73.804.183
5 873.728.197
CoMparSvMm
292
299
330
380
1.000
2.093
2.820
CMI
302.004
1210.880
849.420
1.44U60
1.170.078
907.000
232.780
t 136.240
SyttanStto
fn
tfs
5
M
GUI Annual Cox
3.723,778
19.W9.143
9570.491
29.090.103
21398218
33.437.329
10519,951
1Z414.S06
75879 5308.0 S 1513584 289
11491.9 8388.0 S 2291380 360
5853.4 1918.O S 1.170578 611
8148.9 1110.0 » 1229.780 1.1"
881.2 SZO 1 138.241 Z«20
SyatamSU. OSMCoal A«««iC«.COal CJpCo* Co
WS * SV6B533 J 12.995.801 I37.877.70S
VS S 13.474.873 S 19.895.541 210.773543
S » 9.3292S7 S 15.891.278 . t8e.428.S60
M $ 15,808.953 $ 28,717.547 283,048.075
L S 5511.673 « 6.996583 73.804.183
1513.584 S 2M7Z91S
2291380 S 35.690.504
1.170.878 I 20.30)218
I229.7BO S 43,758289
136.240 » 1Z414.506
Syalomstz. ot
tSJM
.81888
•W8U8.008
lyaamSbo O
M»MI
8M-WM
KI81-18M8
HU«11-»8,»8
•818.I891
•8811 a.3B8
UM-TMM
86M61.tto9.M6
Private Water Systems
UUCoal
1.508.999
7.354.545
3.437.829
10.036.644
9.329.287
11.720.557
4.068.396
SMCOat
1.509.988
7.354.545
3.437.829
10.036944
9.329.297
11.720.587
4.089.399
91.000
93.000
97.000
82.000
87.000
108.000
I2ZOOO
127.000
Amul Cap Coat
» 1.911.884
11.083.917
5283.242
14.81Z298
15.896278
20.719.782
5.997.785
Annual Cap Coat
J 1.911.884
X 11.083.917
S S2S3242
J 14.81Z298
t 15.898.279
1 20.719.782
I 5.997.785
Me. ol SIN* Above
504
ZOSB
906
1.986
789
180
IPS
Monitoring Coat far
Syltam.Abov.ttag.
Unit
S 104.031
t 421J86
198.459
390.493
270.045
83237
_J 37.011
MOMMnfCoalMr
Rag.LMt
1O4.031
421.396
196.450
390.493
270.845
83237
' 37.011
AvaogaOaHyFlow >
(MOD)
aoo7i
0.0346
0.0047
02505
3.2049
11.1710
lo.ofSjn.Abov*
*a*>LMt
413 I
1.428 S
601 S
1.028 S
271 S
31 >
14 5
to.otSya.Abov* I
R*g.LMI
413
1.428
801
1.026
271
31
14
Syatant SyaamSto O8UCoal H
8.530 WS t 8J83533
13203 WS 1- 13.474.673
14.831 S t 9.329287
24.367 M t 15.608.953
58895 L t 551 .673
120.774
330.825
871.798
HH
reramonul '
co*t SyatamSlz* omceat A
288.33 WS » 8583,533
97.12 VS » 13.474.673
41.82 8 3 9529.287
21.86 U » 15.609.953
1638 L U 5511.673
11.15
9.89
ao7 '
wuat Cap Coat
1Z986.801
19.895541
15.899.276
28.717.547
6.989.593
nrwn Cap Coat
12.995.601
19.895,541
15.898.276
28.717.547
6998.593
N*.ofSlle»AI>ov.
H*g.LMI
Z5S3
ZS82
1.087
949
105
MMMtoring Coat lor
SyatamtADonRtg.
LMI
525.417
598,952
274.840
334.082
Monitoring Coat far
Syatim. Above Rag.
LknH
S 512503
S 518,362
J 217.420
S 180.792
S 21.028
Avarag. D*Hy Flow
{MODI
0.0285
0.1930
0.8252
4.0158
37.5902
NakofSyk
Aeova ffa y
LknK
1.6112
1.829,0
449.8
3015
14.1
AflKtad
Syatam*
1.8412
1.629.0
4495
3015
14.1
Coat pa.
SyaMI
S 12.190
S 20593
t 58587
S 141.899
S 870.984
InuainiaM
Coal
109,88
2191
18.38
107
coattoManMora
SW a
SyatamSU* Ma,olsl»a
2S-M8 15574.9
j^j auntSII> OUICoal
t«-)M ' S 14.899210
• t&Utt S 13JS93.702
•Mt-MM S Z023.CS8
M-MJM $ 3,477.899
(8XMM8.9M J Z538.040
p»JB8t-tM408 S 742.593
Ff*quarcyol
lomlortngparYaar
No>otSy«MrM
12361
9778
1705
1531
243
24
Anmul Cap Caat
17.697.558
21.498.322
3.143208
1321.311
4.549.135
1,118.077
ManaMrlngCoat
3.114.972 1
2533.920 1
582.850 t
581.780
243.000
40.440
36.880
Annual Cap Coat
H7.1T0.330
227.753531
33299.191
56^74.047
38,459.852
48,193,603
I 11.823.737
Coat par Syatam
252
298
330
300
1.000
zooo
Z620
MonHonngCoal
3.114.872
Z883.920
582,650
581.780
280.449
243.000
49.440
38.690
SyatamUn
rVS
re
K
H
Total Annual Coal
35.651.738
39275.944
5.729514
9J60.990
5.844.890
7.328.775
1.908,111
3231.723
Ho.o<8IM Ma.ol!Iyalan>i MonurlngCoal Coat par Svatam
299945 22137.0 5M8.892 . 271
572Z2 3236.0 1.144,430 354
1402.2 458.0 280.449 . 811
1482.2 287.0 29Z440 1.005
1834 14.0 36.G80 Z820
SyaMmsm O4MCoat Annual Cap Coal CapCoal Co
WS » 28.78Z912 39.185,878 > 4I4.9Z1870
VS » S.501.554 8.484.519 « B9.S732JS
S J 1.92Z793 3.441.439 « 39.458.852
M » 32792n 5.695.212 S 80.017.340
L I 1.377.729 1.817.314 » 19.25Z649
at Total
5,999.892 S 73,927.882
1.144,430 $ 15.110,504
280,449 > 5544.880
292440 * 9239.868
36.6BO S 3,231.723
syat*mSU*
t»-1M
8*>1-1*M
UM-M.OOI
88j.eiJe.ooe
Mj*et-io*.o«e
S
t
S
S
S
DSMCoat AnnualCipCoal
14.869210 17.0n.558
13.893.702 21.491322
Z023.9S8 3.143206
3.477.899 5J21.311
1J2Z793 3.441.439
Z536.640 4.540.135
74Z583 1.119.077
1.377.729 1 1.917.314
lovolSIMAbov. SyoumoAbov. »
pjao,Unvt Kag-Unil
5200 1.089.819
4503 1.003.770
800 131.458
681 157.658
198 69.013
38 t 13.431
28 S 9.984
lo.otSya.Abov.
n*g.Umtt
4.245
3.403
388
415
68
7
4
Coat par
Sy«*m
S 7.910
S 10.696
S 13.300
> 21.599
> 109.339
< 287.139
S 84Z704
SyatamStt*
WS
VS
S
M
O8MCOH
S 29.78Z912
S 5.501554
1 1.922.793
I 3279233
S 1.377.729
Annual Ca* Coal
S 39.165.678
I 8.484.519
S 3.441.439
> SL695212
1 1517.314
10.103 S
12SI S
280 >
228 S
28 »
LMI
2020576
258,143
5Z085
48,132
5.881
Abo»<^g. Coatpar
IMt SyHan
7547.9 9.148
813.3 17.468
107.8 50263
725 123,937
3.8 841.572
SyctMnSin
p1U.tT49.e09
iM CorwumptJort foaK
IB mM
*9*9»
M.IIX399
*cm-t9.Mt
MA.n49.9M
ML.Mt.1M.9M
O.MCOM
131993.702
Z023.0S8
3.477.S90
1.922.7S3
2.530.S40
742.503
92.000
110.000
«.ooo
10ZCOQ
124.000
110.000
98.000
S
AimMMCapCcMt
17.8S7.SS6
21.40e.322
1321.311
3.441.439
4.S49.135
1.118.077
yttmtAboMf** Av.«5..D*.7yF.ow H-.o*Sy...Ab«y«
1.099.819 0.0052 ««S
1.00X770 0.0219 3,403
131.459 0.0729 369)
157.960 0.1922 «15
88.013 2.735S 96
13.431 9.1202 7
»9M 39.0777 •»
-vawmnUI
Cert
399.03
149.38
44.18
31 J8
13-43
iaro
7.94
SyoMmSlM
WS
VS
S
M
, °2tSS,2 ."— SSS "^"ZOT^ ""T^ *T™ *»-
, J5S. SSS "K, SS ?| *g
> 32792JJ » 5.985212 79.444 3.M84 7Z5 1120
S 1,377,729 » 1817314 9.984 380777 ^ 35 JUJ
!
-------
799 MCL
£SU%££3&!££.
7.031 Wl
BitcuM
\.4A,1+
B.7T2.731
11571737
3.0QXT44
ltof.LMI
7A21S
333.400
279.017
1BZ367
1BZ564
42.625
24.947^
'" »
8.478
1X047
14573
23.743
55.014
109.199
296.416
"M»*
•.90.835 >
121106* $
!«.179.«11
4,100,964
Mf.Un.il Un*
2.013
368242
130.969
113.140
12.334
298.3
20U
54,970
127.009
778.794
M-M*
•tMM
9*OOt4(J4*
I.K.II. ' "ir,.
tgj c,n»MV«M.»l li«y
10.N*
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3J09971
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3
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3.034.43]
10.152.404
13.21X799
12.571,737
3J03.744
3 4.190904
||^»IM<>4.. Hij. AvmgiMlynaw No.fl4Syi.Atm* tncnmnui
Un* (MOD) fte*.Umlt Co*
7051 S 0.0071 314 204.43
335.490 0.0340 1.137 95.97
130X0 OL0047 421 40.90
271.017 02S05 734 21.30
182J07 00252 290 15.00
10Z504 3J049 1B3 10.00
42:023 11.1710 21 9.M
24*47 375902 10 S 722
WS
VS
s
M
1.
5|rtMill*O.I<«H,i. Ayiraptnrtynnw AflKbjO toamim**
ooMC«f« HMMnriyrMi IM* (tnot ijinin. COM
a.r«j.ooo 10.1SOJOO 414,711 o.02or 1.4510 t 10*13
0.394110 13.7091017 417.907 0.1907 1.IS&3 » 25.24
O.Oa.050 10.213.790 102.307 0.0252 290.3 S 15-W
9.043.S3S 10.179.401 225.100 4,0150 203.3 > 9-57
3.212009 4.190.904 24.947 37.5902 9.S t 7.22
l| '.I ,,i
**r{vat* Wattt SytHm*
**
«tf4*f
«778
1TO
1S3I
9472
1034
WWM«J«4
OWOI.M9XO
1^33,752
447.ro
18>«123>
2.11153
2JOOJ12
irooisio
070.107
1.003^77
2.003.920
yftatm
501.703
200.440
243.000
40,440
__ 39,OOP_
Mt.susa
179.405,102
22.000JS1
30.179.0S4
23.411.037
2t244^45
7.090.900
11.591.064
454.492.100
205
330
300
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1.000
iox
2.030
Na.efSHt«
290945
57222
1402.2
1452.2
1034
221370
323&0
459.0
287.0
14.0
91998,892
1.144.430
200.449
292.440
38.380
t.OQS
Z820
3.114.972
2.903.920
502.090
581.700
200.440
243.000
40.440
30.000
roMAMMMlCMI
27.722,132
30.r05.100
4.1HI7S
0.70S.70I
3,731550
4.357J«
t.107.350
1,902.900
SyrtomSIt*
WS
V*
S
22,180799 f 3O307.3S4 S
3.816.158 S 5.059.461 $
U41.198 S 2J09.012 t
Z001.475 S 3.430,703 %
30.0TZ7I4 5 42.900.547 5
T4M
t S0.407J41
S 10.G20.03T
S 3.791.550
$ 1724,815
5 1.902.900
90.7MvU»
OIMC^<
> II20.M
» H.940.033
» IJ00.490
> 2.429,nO
t U« 190
1
I
_1_
13J87.3I8
14940238
2.101JZ3
2.703L510
070,107
_Laa2jr_
II**. LMt
1M3
3,801
112
23
9y«4nMAtwv* H*.fltSr«.Ah*v* CMIBOT
•14.070
790.173
92.040
112.032
43,099
44.49T
8.0S3
»."7
*•>«
ZToa
279
290
72
44 S
4 >
3 5
7.004
10.507
13.004
21.030
40,070
9T.99T
250.430
754.035
5 22,180.795 S
5 3J16.1S8 $
5 1241.199 5
S Z001.47S S
S 823.091 S
Mia.vC.Ml
30307^54
SJ99.451
2209.912
3,430,703
1.033227
7.833
884
UmM
1.S88.0S3
179.737
3X435
26,906
3.375
5.941.7
575.4
71.3
48.9
26
fl.OW
17.124
48.733
1I1.B58
752.732
U4U90
! .Ml 732
447,723
» «33°H »
2.101 J25
3.000J20
239U12
2.790410
07B.I07
'.°Qg7
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014.020
7W.173
92.040
111052
43AO
44.407
».aa
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(MOO)
0.0052
ao2is
00720
ai922
0.0543
2.7355
9.1202
3OOT77
>IOy*.Atev» tnmrmnM
tof.LMI Ce«t
3O.10
147.04
43.40
3050
25.30
12.17
95S
7,10
31233
2.708
279
298
OtMCMt nt
22.180.795 S
3J18.158 S
1241.199 S
Z001.475 S
30307.554 1
3,838,431 t
2209412 5
X430701 t
1.81X799
204.691
SXSSO
6,717
0.0127
111342
0.6543
33094
38.0777
X941.
579.
C
-------
1000 MCL
Co* to Monitor •
MenMwtngtwrYMr
syttmsu* Nao«sitM
2S.1M 15145
MUM 8063.4
OT-IOM 4247.1
1M1.3.3M 7204.8
•M1M1.U.OM 4985.0
MM1-1M.OM I'513
1M.H1.1.W>.9M 981 2
SymmSU* OUlCoK
2S-1M 824.708
Wt-8441 4.431.119
MftM8 1.515.229
M61-UM 4.591.896
tt.S61-M.9M 4.021.149
SM61.1M.OM 1.357,933
-moot-i.eo9.Qo8 * 1.774.013
Tfecai » 2ZI47,2S6~
Nfxe4Sy*ttn»
(202
4tM
2574
3702
SB7
1T3
»
Annul Cap Co*
1.048.914
8.557.814
2332.553
6.588.776
6.100.388
6.975.729
1.975.848
34.050.846
MMtferinffCo*
302.904
1.210,690
849.420
1.440.960
907.000
232.780
138.240
CapOKt
11.G01.02S
70532.972
24.711.100
8S.801.SM
69.474.890
73.900.976
20.MO.017
24.387.938
COM parlytMni
252
298
330
380
1.000
Z080
2.820
C«4t
30Z904
1.210.00
849.420
1.440.980
1.170.878
997.000
232.790
1 138.240
SyatomSb*
•VS
n
%
M
L
Tetal Annual Co*
3.174.526
12JW.813
4.697.202
1Z591.635
11.012.300
11.90.879
3.598.256
4.21Z301
t »U47.M>
M.CJUM NauMSraMni Merilarinf COM Coal par Sy>m
7587.9 5308.0 1.513.364 * 285
11491.9 6368.0 2290.380 9 380
5803.4 1916.0 1.170.878 » 611
614M 11100 129.790 > 1.108
681.2 52.0 136540 * 2.820
l|H»mnln OAMCoat Annual Cap Coal CapCoa*
WS » 9.255.827 7.704.726 S 81.823.997
VI I 6.077,128 Maya S 94.5I2.8M
S S 1661.346 6.190J68 S 65.474.100
M > 5.37H.S82 8SS1.37S S 94.830.993
Coal
1.513.584
Z290.380
1.170.676
1229.780
138,240
Mai
14.474.130
17.280.937
11.012.399
15J60.137
4212.301
1M1-34M
MJfl-iet.OM
SysMmSlM
».IJO,JW,000
HH CatttunvOon toalK
2C-1M
1M.e01'1.0W.OOt
OtMCOJt
824.708
4,431,119
1.515229
4.581 .890
3,081,346
4.021.140
1.357.833
OtMCort
824,708
4.431,119
1,515.229
4.501,890
4.021.140
1.357.833
81,000
93.000
97.000
82.000
87.000
108.000
122.000
127.000
AnnMtCapCort
1.046.914
6,657.814
2332.553
8,586.778
8.975.729
1.975.648
_$ 2.30ZQ4B
1.048.914
6.6S7J14
1332.553
8.588.778
8.975.729
1.975.848
Ho. of SAM Adorn
(te^Lkntt
277
1.260
397
240
58
Unit
$ 57.788
S 259.649
S 90.542
185.965
11ZB93
26JSS
15.427
SyKtmAtevt Na.ofSy.vJ
57.788
250.849
90.542
185.985
11Z803
28.358
15.427
Av-Kao* Daty Fto* Ngibf Syt.J
(MGO) R*9.Un
0.0071
0.0348
0.0947
0.2505
33040
11.1710
37.5902
htovw
tt
229 $
860
274
480
113
13
0
itev* in
«
229 S
880 $
274
480
113
13
6
SyMn.
8.417
1Z694
14.354
23.185
98.410
262£84
694.874
tnmtnut
Gout
262.53
94.84
40.28
20.78
19.44
9.00
7.88
6.43
NtxofSMt.tA.MV* Sy*.n.*Atomft*,> *
SyaMmSte OCMCe*! AnnudCafCo* lto»UT* Urn*
WS * 5JS&827 $ 7.704.728 1.537 307.308
VS * 8.077.128 $ 8*21.329 1.156 231.103
S S 3.681.346 * 6.180,306 422 84.300
M S 5J7B.982 J 8.951,375 307 61,338
L S 1 774013 $ 2.302.048 34 8.79S
Sytf-jmAbowR.!* Avmg*Mi.yBow
SytnmSU* O4MC*6*I AnmMlC.ipCo.tf Umif (MOD)
WS S SJSS.327 J 7.704.728 317.417 00298
V» $ 8.077.128 J 8.921.329 278.508 0.1945
S * 3.681.346 » 6.180.308 113.758 0.8252
M S 51378.982 S 8.951.375 139.251 4.0156
L S 1.774.013 $ 2.302.048 15.427 37.5902
'
Lfcuft
1.100.4
783.8
1882
125.7
SO
t.109.4
763.8
1882
125.7
5ft
CMtpW
11,960
10,040
53.313
114.503
693.409
CMC
102,52
24,62
t&44
ftse
9.43
PtivaM Water SyiMmt
Monitoring par YMT
Sy^amSU. No-OISIM
K.1M 1SS74.9
MI-tM 14419.6
•M.1MI 2913.3
tt81J^M 2WB.9
tt\M14«.Mt 1215.0
•6JM1-1M.OM 247.2
4MM1-1&M.OO* 193.4
SyttwnSix. OftMCeat
M.1M S 8.133.708
ttf-«M S 8J75.472
681-10M I 891.539
M9143M S 1.590.251
M461-M.OM > 870.965
6UOMM.M9 > 246.322
106.M1-1.000.OM S 460.080
Srnm91i. 04\UCoal
2S.1M S 8.133.708
W1.U* S 8,375.472
M1.100. 891.539
S^61.1fl.OM 754.170
tt.M1-M.MO 870.895
M^M1.1M.OM . 249.322
Syt*am8lz. O4MCOM
2S-1M 8.133.709
M14M 9.375.472
W1.1MI 991.539
W814JM 1.590.251
XM1-19.0M 754.170
1M6140.M9 870.895
MJMMM.M9 246.322
HHConauixKlonlaall:
36-1M 9ZCOO
W1408 110.000
68t.1«M 99.000
S^61.19.M9 124,000
WJM1-MJM 110.000
MJM1.1M4M 99.000
tt6jM1.1.0M.M9 114.000
- Y^uiAnnmi
12361 S 3.114,972 » 252
9776 S 2.883.920 S 296
17D5 S 582.6SO S 330
1531 1 581.790 t 3»
243 S 243.000 5 1.000
24 5 49.443 S Z083
14 s 36.680 S 2.620
AnnualCvO* AnourfOpCoal MonawtooCo-
» 9.687.829 I 1OZ83Z9« S 3.114.972
» 1Z97S.199 J 137.459.412 » ZS53.920
» t.306.506 1 14.696.685 S 56Z650
I Z400.718 S 25.433.240 » 591.780
J 1.336,581 S 14.158.545 S 2W44J
S 1.530,799 » 16ai7.296 S 243.000
S 387.116 J 3.689.231 5 49.4«9
5 800.458 J 4361.285 $ 36.690
9.697.929 Z962 I 594.067
1Z975.19S 3.000 S 618.500
1^6.506 283 t 59.975
2.400.718 306 S 75.O83
1.530.798 81 5 27^16
397.116 12 5 iSW
900.4S. 9 » 4.153
AnnuHCapCoat Un« """i,.-,
9687.829 594.067 0.0052
1Z975.196 616.500 0.0216
1.389.506 59.975 O.0729
2.400.710 75.083 0.1922
1530.798 27.516 Z73S5
367.116 5.596 9.1202
S 900.459 4.153 390777
WS 29994.5
VS 57212
S 1402.2
M 146Z2
t 183.4
Total Annual Coat SyttamSli.
20.938.510 WS
242M.5B9 VS
Z840.697 S
4.S8Z749 M
Z371.179 L
Z644.483 ratal
682,879
1.097.216
Z357 7.812
Z097 10.479
182 1Z965
199 20.529
29 89377
3 227.789
2 S 871.620
No.ot3ya.Abov. tocfamantal
>»g.LMI COM
Z357 380.55
Z097 148.33
182 4174
196 29.85
28 10.96
1 8.49
2 9.32
22137.0 5^66.892 $ 271
32J3.0 1.144.430 I 354
469.0 290.449 S 811
287.0 292,440 S 1.096
14.0 36.690 S 2620
OUICoM AnmMCapCoM CapCoM COM
16.509.181 2Z603.025 240.09Z411 5.998.892
2.471.79(1 3.797228 40.121J25 1.144.430
754.170 1.336,561 14.150*45 280.449
1.116.9611 1JB7.914 2aiO«S27 29Z440
400.000 600.459 6.361.285 36.690
SynmiSli. OIUCoM AmuMCapCoM •*g.Un»
WS 16,509.181 S 2Z893.025 S.962
VS Z471.790 > 3.787226 599
S 754.170 > 1.336.581 101
M 1.116,999 > 1.897.914 73
L 490.060 S 800.459 '
SyM«mAl>ov.Rag.
SyttamSIn 0«MCoM AnnuilCapCoM Untt
WS 16.509.181 2Z963.025 S 1.21Z569
VS Z471.790 3.787229 > 135.057
S 754,170 1.339.561 S 27252
M 1,UBJ» 1.897.914 S 33.114
L 490.060 800.458 1 4.1S3
Total
S 48.171.098
S 7.403,416
S 2371,179
I 3J07.342
> 1.097.218
Una) Urat Syiaam
S 1.17Z424 4.454.0 9.059
S 113.635 370.3 16.800
S 20.195 44.6 47.329
S 14,509 302 100204
t 1.829 1.6 670.154
1X00) SyMano C«M
0.0129 4.454.0 193.52
0.1349 379.3 3Z63
0.6543 446 24.8S
3.3094 3012 9.09
360777 1.6 6.32
-------
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1.31 IBM
U 31*23
Sl*.90*
3J11057
09U77
7*T"00*
220243*
tj2*iao
531,150
022273
29.013
152054
35.450
75JJ41
42729
37,900
0,851
5.183
Na.et3y«.Atevo
Haf.Umtt
•JOS
12623
11800
22035
51.467
61,610
211.300
562433
SytMmSto
WS
OtMCoM
2951.020
2342150
1,313.850
1.493,918
401.554
riCM>CoM
4.330,028
3.417.094
220243*
2455.319
622273
NohefSNesAbew
Rag-UmH
Monrtortnf Coat tor
174.169
87.912
30.021
18.014
1.774
630.6
308.7
11.823
19.130
51.310
94.096
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152064 0.0340 SIS $ 92DS
35.450 0.0047 107 30.23
75.341 0.2505 190 19.77
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37.900 37049 30 754
8.531 11.1710 4 &33
5.180 375002 2 571
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s
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Syatomo Atom Reg, AvtragaOaiff Flow Affected tacnmantal
OAM CCM Aimuat Cap COM Unt (MOO} SyMama Coat
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2342156 3.417.664 110.790 0.1957 305.7 23.40
t .31 3.050 2702439 42229 0.8252 69.1 1 4,87
1,480,918 2455.319 40.759 4.0158 422 7,00
4*1.554 522273 5,180 37 5902 20 5.21
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531.0* ICO
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23.482 71
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1226&58* 3.170
1.449.940 210
470.004 30
520.421 19
1S22S4 2
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5y«Nm«Abov*R»f. Atevona?.
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034.045 2411
43.209 151
7.192 16
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9,013
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lyMMMAteMltaf. Avorago Datfy Flow He. of Sy*. Atevo.
LMI p*3O) Ho*.IJMI
290J64 O.OOS2 1.164
302727 0.021* 1728
33.402 007M 71
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********
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375.03
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VS
s
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0,838.103
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270.527
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AnnutCvCoM LMI (MOO» SyMmo CoM
1276*^66 S 060.501 0.0133 2411.9 1 164.91
1.449^40 S 33.900 0.1356 1517 S 31.22
476.004 S tail? a0543 10.0 S 23.73
520.421 * 11.119 3.3094 107 t 7.40
1622*4 S 1.395 30.0777 0.5 S 5.12
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tajaa
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Mentoring par VMT
smomSIu Mo,ol5IM
U-160 <514.5
99t.I6* 6053.4
Kt.1l*. 4247.1
Mtl * ^# 7204.6
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M.661-69J966 4995.0
96.661-16*416 "63.9
nou _
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C91-1M* SW
..•1 * **f 614033
X564.MJ96* 438.666
16561 16586 280.735
66.061-1.M66 66587
Tow S 1322.399 I
TUIIMIITI™ OAMCoot
2;!Se » "aw*
XM1.1.MM ^ 439.888
.AMI-MUM* S 280.735
MjM1.K*Mf * M.OT
l^^uta.idClMt.l
SntamStz* OUICott
2S-1M «M»
Itl-M* t.393,018
•01-tMB 205.829
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XM1-MUQM 439.688
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i«H CoAwmpiien (oam
•IM-IM 33.000
W1.1M* 97-000
jj&t 18 J»l 87.000
M.M1-M4M '06.000
M.M1-MMM 122.000
4M.M1-1.OM.Mi> 127.000
Private Watw Systems
Cotri to Monitor •
W-iM 15574fl
1914M 14419.6
M.1-10M 2813.3
1C.M1-MJM ^215.0
M.M1-1MJM 247.2
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XS.1M * 1.008.112
M1-M* Z633.933
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M8143M 21Z526
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M1-M* Z833.S33
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1M1-X3M 212.326
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HH C4»n«unmttan to*}:
tf-IM 9ZOOO
t*1-M« 110.000
•4-1-1W* 88,000
tM1-3^M> 10ZOOC
l,U1*1t^}M 124.00C
t*M14».6M ttftOOt
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$ 4.0QB.648
187.901
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4.089,648
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3t9.803
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S 4.C09.846
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102X2
23.523
uiasto s
840,420 S
1.440,900 J
997.000 S
232.790 S
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Aft
Z48B.823 S
22.086.357 S
3.351,908 S
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4.979.S4S $
t.346.373 *
1.5S9.B03 S
5^878.922 _S_
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2 $
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13.219
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3.114.972
2.6S3.920
56Z650
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40.440
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23,082,008
43,431.710
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3.385,975
1.674.S68
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S 75.328.735
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302,904 720.959
1.210.680 4.686.494
849.420 1.371 .831
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23Z780 440,438
136.240 S 403.446
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"^STLW* BM,Un*
27.146 71
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3.2049 11
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37,5902 1
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3.114.972 S 7.tOZe08
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583.050 S 871.529
581.780 * 1.113.911
200.449 S 529.009
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8.572 21
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£
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299945 22137.0
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S 90.482
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1513.554 265
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2519.723 24575.190 S 1513584
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S 1576,146 5 2519.723 488
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S 8279.399 S 66523.715 5.986.102
S 507.504 S 5578.506 1.144.430
S 1S9.097 1 1.674599 280.449
S 126508 S 1540201 292.440
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5 333.506 507.504 75
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S 93.826 340.6 11.713
1 30.503 110.7 16.466
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S 3.715 11.6 82.350
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0.0304 3406 96.34
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$ 16.720506
S 1.965.440
S 529.009
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5 108.178
Monitoring Cooler M^ofSyK
LMI UK* S»«m
322.460 1225.7 9.010
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36.0777 0.1 443
-------
I'll:'' • t
•I, S,
i1:! f
if, j ' fin
Eli,
-------
APPENDIX E. MMM Scenario Cost and Benefit Tables
-------
-------
SCO CO
O> T-
d d d
odd
m m tn
p o> •<*;
odd
=
& 0 Q S 5
1 fjfjtil1
** 5 S co 2 T^ O» co
3 «> 5 |> )5 ._ JjJ «_:
3 m "5* •- ^ O ^ ^
1
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S ^ 1 S S.1.S2
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1 IIP I|l
co ^l2-SQ.2>g
S >. °" f 'a ii °
< ilgftfs i§
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— c 91 13 o ra a
%, -SSSoi-S.a)S
TMM
S S d «
«
**
2S5 g
u>
T- W
(D
0
1
501-3300
3300-10.000
10,000 -100.000
>1 00,000
Total CWS Water l\
Costs
UJ
•c
(0
c
o
o
CO
0
o
•c
1
o
•i
(I
CO
CD
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n
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mini strati
Water System Ad
Costs
to PO CM d d d
p CM f^ -C CO O
o co co en T- i-
q [ co en
P-
8
in
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•* o o r- •«-
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d
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13300-10,000
o
8
o"
O
o"
o
•r-
£
c5
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•<»
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s
1
o>
1 Total CWS Admin
Costs
3
S
0
$
5 D
r
r
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M (I
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and Administratio
S
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2 a> ^ 3> Q *® £
12 11 E |3 »
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flow
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rograms,
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a
5
ii
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reviewin
strubtabl
12
I c
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o)'5
3 '
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= •
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»*• 55 co »- A
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to (d »
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odd
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o
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g|£:l|l|
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Costs
UJ
•c
cs
C
^
a
CO
s
to
o
o
•c
C
a
£
m
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^
(
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dministrative
ts
Water System A
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co co CN d d d
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o
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r— v
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110.000-100,000
o
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8
t^.
e*i
m
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2
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I Total CWS Admi
Costs
to
w
O
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1
c
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(it
°c
1
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3
o> u
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on Costs
Total CWS Wate
and Administrat
n S"5=S
c 'a -3^ i j: -V f
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2.
w
s ill!
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= « 1 • r. ••§. g 2
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iity!!1
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ffereni sysle
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m 01 co
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5
2
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UJ
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1 &
2
i
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implementation)
CO
CO
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(N
1
S
(State MMM Cos
limolementation)
01
o
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c
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1 Total MMM Imp
Costs
CD
CM
CM
a
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00
r^
ir
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T-
CO
C
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APPENDIX F. NTNCWS Cost and Benefit Tables
-------
I","
-------
An Analysis of the Potential Benefits and Costs of Radon in Drinking Water
for Non-Transient Non-Community Water Systems (NTNCWSs)
The following tables provide an analysis of the fatal and nonfatal cancer cases per year,
benefits, costs, and costs associated with five MMM implementation scenarios for Non-Transient
Non-Community Water Systems (NTNCWSs). Table 1 provides the estimated number of
reduced fatal and nonfatal cancers and health risk reduction benefits at each MCL level. Table 2
provides the national water mitigation only costs for NTNCWSs. Table 3 provides benefit-cost
ratios at each potential MCL. Table 4 shows the incremental benefits and costs at each MCL
level. Table 5 shows the total and incremental costs per life saved at each level and Table 6
provides the total system and state c osts for NTNCWSs for five MMM implementation
scenarios.
Some key inputs and assumptions used in this analysis::
• Total numbers and size distribution of NTNCWSs are from the Drinking Water Baseline
Handbook (US EPA 1999A) ',
• Distributions of radon levels are from the revised distributional analysis used in the risk
assessment for NTNCWSs
• NTNCWSs are assumed to have the same distributions,'number of sources per system, the
same distributions of pre-existing treatment technologies, make the same type of
mitigation choices, and have the same mitigation unit costs as public ground water
systems.
-------
Table 1. Cancer Risk Reductions and Monetized Health Benefits1
Radon Level
(pCi/l)
None
4000
2000
1000
700
500
300
100
Cancers/Year
Fatal
1.76
1.71
1.62
1.44
1.30
1.13
0.83
0.29
Non-fatal
0.10
0.099
0.095
0.084
0.076
0.066
0.048
0.017
Reduced Cancers/Year
Fatal
0.000
0.052
0.13
0.31
0.45
0.63
0.93
1.46
Non-fatal
0.000
0.0030
0.0078
0.018
0.026
0.037
0.054
0.085
Benefits
($Million/yr)2
$0
$0.30
$0.78
$1.8
$2.6
$3.7
$5.4
$8.5
1 . Source of cancer risks and risk reduction estimates: W. Brattin Fax of 7/7
2. VSL (fatal cancer) = $5,800,000; WTP (non-fatal cancers) = $536,000
-------
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Table 3: Benefit-Cost Ratio at Potential Regulatory Levels
Radon Level
(pCi/l)
None
4T300
2000
1000
700
500
300
100
Benefits
($Million/yr)
0
0731T
07/8
1.83
2T.65
3.67
5.41
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Costs
($Millions/yr)
0
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24.60
54.11
/7.15
102.91
145.54
223.95
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Ratio
0
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0.036
0.037
0.038
Net Benefits,
$Millions/yr)*
0
(11.63)
(24.56)
(64.08)
(//.12)
(102.87)
(145.50)
(223.91)
Table 4: Incremental Benefits and Costs
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Radon Level
(pCi/l)
4000
2000
1000
700
500
300
100
Incremental
Benefits
($Millions/yr)
0.30
0.48
1.05
0.81
1.02
1.74
3.13
Incremental
Costs
($Millions/yr)
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13.0
29.5
23.0
25.8
42.6
78.4
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