PRELIMINARY HEALTH RISK
REDUCTION AND COST ANALYSIS
REVISED NATIONAL PRIMARY
DRINKING WATER STANDARDS
FOR RADIONLCLIDES
Review Draft
Prepared for:
Office of Ground Water and Drinking Water
and
Office of Radiation and Indoor Air
U.S. Environmental Protection Agency
Prepared by:
Industrial Economics, Incorporated
2067 Massachusetts Avenue
Cambridge. MA 02140
(617)354-0074
Januarv 2000
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PREFACE
This report was completed by Industrial Economics, Incorporated (lEc) for the U.S.
Environmental Protection Agency (EPA) under Work Assignment 2-43 of Contract 68-W6-0061,
building upon work completed under previous work assignments. The Work Assignment Manager
is William Labiosa of EPA's Office of Ground Water and Drinking Water. In addition to drafting
this report, lEc conducted the occurrence analyses (reported in Chapters 2 and 5) and the risk
analysis (reported in Chapter 3). The cost analysis (reported in Chapter 4) was conducted by
William Labiosa of EPA.
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TABLE OF CONTENTS
EXECUTIVE SUMMARY ES-1
CHAPTER ONE: INTRODUCTION AND REGULATORY FRAMEWORK 1-1
Regulatory Options 1-1
Requirements for Economic Analysis 1-3
Comparison to 1991 Analysis 1-7
General Approach 1-7
Baseline Definition 1-10
CHAPTER TWO: BASELINE OCCURRENCE 2-1
Analytic Approach 2-1
NIRS Data 2-2
Initial and Revised Baselines 2-9
Systems Serving Populations Greater than One Million 2-14
Findings 2-15
Community Water Systems: Gross Alpha and Combined Radium 2-16
Community Water Systems: Uranium 2-27
Community Water Systems: Summary of Results 2-30
Systems Serving Populations Greater than One Million 2-31
Implications of Limitations in the Analysis 2-34
CHAPTER THREE: RISK REDUCTIONS 3-1
Analytic Approach 3-1
Risk Factors 3-1
Changes in Occurrence and Exposure 3-8
Valuation 3-13
Findings 3-21
Community Water Systems: Gross Alpha and Combined Radium 3-21
Community Water Systems: Uranium 3-25
Community Water Systems:
Summary of Results and Value of Risk Reductions 3-27
Implications of Limitations in the Analysis 3-29
Risk Coefficients 3-30
Other Sources of Uncertainty 3-31
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TABLE OF CONTENTS
(continued)
CHAPTER FOUR: CHANGES IN COSTS 4-1
Analytic Approach 4-1
Types of Compliance Costs 4-1
Per System, Per Household, and National Cost Estimates 4-8
Findings 4-12
Community Water Systems: Gross Alpha and Combined Radium 4-12
Community Water Systems: Uranium 4-16
Community Water Systems: Summary of Results 4-18
Implications of Limitations in the Analysis 4-22
Compliance Actions 4-22
Market Impacts 4-24
Other Sources of Uncertainty 4-25
CHAPTER FIVE: NON-TRANSIENT NON-COMMUNITY WATER SYSTEMS .... 5-1
Analytic Approach 5-1
Data Sources 5-2
Approach 5-4
Findings 5-6
Implications of Limitations in the Analysis 5-9
CHAPTER SIX: SUMMARY AND CONCLUSIONS 6-1
Comparison of Costs and Benefits 6-1
Implications and Key Limitations 6-8
APPENDICES
Appendix A: Number of Water Systems and Population Served:
Community and Non-Transient Non-Community Water Systems A-l
Appendix B: Histograms of Occurrence Data B-l
Appendix C: Detailed Risk Results for Community Water Systems C-l
Appendix D: Decision Trees for Community Water Systems D-l
Appendix E: Detailed Occurrence and Cost Results for Community Water Systems E-l
Appendix F: Trends in Costs and Risk Reductions Associated with Additional
Radium Options F-l
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EXECUTIVE SUMMARY
The U.S. Environmental Protection Agency (EPA) is considering changes to the regulations
governing the allowable levels of radionuclides in drinking water. The Notice of Proposed
Rulemaking for these revisions was published in 1991. Since that time, additional information on
the impacts of changes to these standards has become available, and EPA is publishing a Notice of
Data Availability to publicize this new information. The Notice summarizes the risks and costs
potentially associated with revisions to the standards; this report provides more detailed information
on these impacts.
BACKGROUND
EPA first promulgated standards regulating the concentrations of radionuclides in drinking
water in 1976 as National Interim Drinking Water Regulations (see 40 CFR 141). In 1986, EPA
published an Advance Notice of Proposed Rulemaking, which discussed additional information on
the occurrence and risks associated with radionuclides in drinking water. The Notice of Proposed
Rulemaking (NPRM) for revisions to the radionuclide standards was published in 1991. The
subsequent Notice of Data Availability (NODA) that this report supports provides additional
information on the topics addressed by the NPRM.
The current regulations establish Maximum Contaminant Levels (MCLs) of 5 pCi/L for
radium-226 and radium-228 combined and of 15 pCi/L for gross alpha (net of uranium and radon).1
In the 1991 NPRM, EPA proposed to revise the combined radium and gross alpha standards and to
create an MCL for uranium. Separate, higher standards were proposed for radium-226 and radium-
228, while the standard for gross alpha would remain the same but be redefined to exclude radium-
226. EPA is now considering instead whether to limit the contribution of radium-228 to the current
1 The current and proposed standards also address the MCL for beta and photon emitters.
This preliminary analysis does not consider the costs or risks associated with changes to the
standards for these radionuclides because EPA expects that the impacts of these changes will be
relatively small.
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combined radium MCL, and whether to revise the gross alpha MCL to equal 10 pCi/L excluding
radium-226. EPA is also considering MCLs for uranium at either 20 ^g/L (20 pCi/L), 40 ^g/L (40
pCi/L), or 80 ngfL (80 pCi/L). The NODA provides more detailed information on the rationale for
considering each of these regulatory options.
In addition to revising the MCLs, both the 1991 proposal and the current NODA propose to
alter the requirements for monitoring and analysis. The existing regulations include inadvertent
loopholes that allow systems to "legally" exceed the current MCLs. These loopholes include: (1)
systems may avoid analyzing their water for compliance with the combined radium standard if their
measured gross alpha activity level is reliably below 5 pCi/L; (2) systems may avoid measuring
radium-228 in cases where radium-226 does not exceed 3 pCi/L; and (3) systems may hold their
gross alpha samples long enough to allow radium-224 to decay below detection limits.
Under the first two loopholes, some systems may legally exceed the MCL of 5 pCi/L for
combined radium because the regulations allow them to avoid measuring activity levels for radium-
228.2 Under the third loophole, systems with elevated levels of radium-224 may legally exceed the
MCL of 15 pCi/L for gross alpha because of the length of the allowable holding time for the
samples. EPA is considering whether to close these loopholes to ensure that all systems achieve
radionuclide levels at or below the existing MCLs.
In addition to changing the MCLs and monitoring requirements, the proposed rule would
extend the requirements to non-transient non-community water systems. The current regulations
apply only to community water systems. The regulations (at 40 CFR 141.2) define a community
water system as "a public water system which serves at least 15 service connections used by year-
round residents or regularly serves at least 25 year round residents." A non-transient, non-
community water system is defined as "a public water system that is not a community water system
and that regularly serves at least 25 of the same persons over 6 months per year." These systems
often serve locations such as schools or office buildings.
OVERVIEW OF THE ECONOMIC ANALYSIS
Analysis of the costs, benefits and other impacts of regulations is required under the Safe
Drinking Water Act Amendments of 1996, Executive Order 12866 ("Regulatory Planning and
Review") and EPA's internal guidance. Related requirements have been revised substantially since
EPA published the 1991 proposal for changes to the radionuclides regulations, and the new
requirements guide the economic analysis presented in this report. In addition, there are several new
2 Radium-228 is a beta emitter, whereas radium-226 is an alpha emitter and included in the
measurement of compliance with both the gross alpha and combined radium MCLs.
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statutory and administrative requirements for assessing the distribution of costs and benefits and
equity concerns, focusing on groups such as small businesses and children.
The analysis in this report represents the first step in the development of a comprehensive
economic analysis for the radionuclides rule. It provides preliminary estimates of national costs and
benefits, and presents information on the data sources and analytic approach used for review by
interested stakeholders. This analysis will be subsequently refined as needed to respond to
comments, incorporate new data, and address key sources of uncertainty. In addition, it will be
expanded to include assessment of distributional effects (e.g., on small systems and sensitive sub-
populations) as required by various statutes and administrative orders.
The basic steps in a comprehensive economic analysis include: (1) estimating baseline
conditions in the absence of revisions to the regulations; (2) predicting responses to each regulatory
option; (3) estimating changes in national costs; (4) estimating changes in national benefits; and (5)
assessing distributional impacts and equity concerns. In this report, we develop preliminary
estimates of national costs and benefits, focusing on monitoring and compliance costs and reductions
in cancer risks. Other national costs and benefits (e.g., state administrative costs and risk reductions
from incidental treatment of co-occurring contaminants) and potential distributional impacts are
described qualitatively.
The first step in the economic analysis, defining the baseline, provides unusual challenges
in the case of the radionuclides regulations. Several community water systems are not complying
with the existing regulations, in part because they are anticipating the proposed changes to these
requirements and hope to avoid unnecessary costs. Also, as discussed earlier, there are loopholes
in the current monitoring requirements that allow some systems to legally avoid compliance with
the current MCLs. To address these issues, this preliminary analysis considers two baselines.
Initial baseline: Under this scenario, we assume that systems would be required to
comply with the existing regulations as currently written. Community water systems
could exceed the existing MCLs only in cases where they can legally avoid
compliance due to the loopholes in the monitoring requirements.
Revised baseline: Under this scenario, we assume that EPA would alter the current
regulations to eliminate the monitoring loopholes, so that all community water
systems would be required to achieve the existing MCLs.
This dual baseline approach allows us to separate the costs and benefits of changes in the monitoring
requirements and from the costs and benefits of changes in the MCLs. It also avoids attributing costs
to the new regulations that are in fact attributable to achieving compliance with the regulations now
in force.
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APPROACH FOR ASSESSING OCCURRENCE, RISKS AND COSTS
The first step in the economic analysis involves estimating baseline occurrence in the absence
of revisions to the regulations. To develop these estimates for community water systems, we begin
by extrapolating from data obtained through EPA's National Inorganics and Radionuclides Survey
(NIRS). This survey measures radionuclide concentrations at 990 community ground water systems
between 1984 and 1986. We adjust these data to address certain of their limitations, including (1)
the small size of the sample for systems serving populations greater than 3,300 persons; (2) the decay
of radium-224 prior to analysis of the NIRS water samples; (3) the need to convert mass
measurements of uranium to activity levels; and, (4) the lack of information on surface water
systems.
Because of uncertainties related to extrapolation from this sample to national estimates, we
apply two approaches. First, we assume that national occurrence is directly proportional to the
occurrence levels measured in NIRS. In other words, if one percent of the systems in a particular
size class in NIRS are out of compliance with a regulatory option, we assume that one percent of all
systems in that size class nationally are out of compliance. Under the second approach, we fit a
lognormal distribution to the NIRS data for each system size class and group of radionuclides, then
uses this distribution to estimate the percentage of systems out of compliance nationally. The
properties of the lognormal distribution depend on the underlying NIRS data, but applying this
distribution often increases the estimates of the proportion of systems out of compliance as well as
the amount by which they exceed the MCL of concern. This approach recognizes that actual
national occurrence levels will vary from the levels observed for the systems included in NIRs.
Under both the direct proportions and lognormal approaches, we develop an initial baseline
for combined radium and gross alpha that reflects full compliance with the existing regulations as
written. We implement these adjustments by identifying systems in illegal compliance status and
adjusting their gross alpha and combined radium concentrations downwards, to reflect the impacts
of installing treatment or taking other actions to achieve compliance (such as changing water
sources, blending contaminated and uncontaminated water, or closing contaminated wells). A
similar approach is used to subsequently adjust the data to account for closure of the monitoring
loopholes, which leads to development of the revised baseline where all systems are at or below the
current MCLS. These adjustments are not applied to uranium, which is not currently regulated and
tends not to occur above levels of concern in systems affected by the existing monitoring loopholes.
After determining the number of systems out of compliance with each regulatory option
under consideration, we assess the risk reductions associated with requiring compliance. The
approach for the risk analysis begins with the development of risk factors for each group of
radionuclides. These factors involve multiplying the mortality and morbidity cancer risk coefficients
for each group of radionuclides by standard assumptions regarding drinking water ingestion to
determine the risks associated with annual exposure. We then apply the individual annual risk
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factors to the estimates of the reduction in occurrence associated with each regulatory change under
consideration, taking into account the population exposed.
Once we estimate the reductions in fatal and nonfatal cancer risks associated with each
regulatory option, we assess the value of these reductions using generally accepted economic
valuation techniques. To estimate the monetary value of the reduced fatal risks (i.e., the risks of
premature death from cancer) predicted under different regulatory options, we apply the value of a
statistical life approach. A "statistical" life is the sum of small individual risk reductions across an
entire exposed population, not the value of saving the life of a particular individual. For nonfatal
cancer risks, we use data on the cost of illness to value the risk reductions.
The third component of the analysis involves estimating the costs of the compliance under
each regulatory option. The options under consideration will increase the costs of monitoring for
all systems as well require certain systems to take action to reduce the concentrations of
radionuclides in their water. These latter actions may include installing treatment or changing the
water source used. The analysis considers both capital costs and operations and maintenance costs,
and includes a number of treatment technologies. The options of complying by purchasing water
from neighboring systems, blending, or using alternative water sources are also considered.
SUMMARY OF FINDINGS
In Exhibit ES-1 below, we estimate the number of systems likely to be out of compliance
with each of the regulatory options assessed in this preliminary analysis.
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Exhibit ES-1
NUMBER OF COMMUNITY WATER SYSTEMS EXCEEDING STANDARDS
Option
Number of
Systems
Illegally out of compliance with existing MCLs (combined radium = 5 pCi/L, gross alpha = 15 pCi/L) '
Illegal noncompliance: gross alpha
Illegal noncompliance: combined radium
Total number of systems in illegal noncompliance (adjusts for overlap)
400 systems
420 systems
670 systems
Legally out of compliance with existing MCLs (due to monitoring loopholes)2
Legal noncompliance (due to monitoring loopholes): gross alpha
Legal noncompliance (due to monitoring loopholes): combined radium
Total number of systems in legal noncompliance (adjusts for overlap)
210 -250 systems
270 - 320 systems
3 1 0 - 400 systems
Out of compliance with options for revising MCLs 3
Gross alpha at 10 pCi/L net of radium 226
Combined radium at 5 pCi/L with radium-228 limit at 3 pCi/L
Total number of systems out of compliance with revised radium or gross alpha MCL
(adjusts for overlap)
500 -6 10 systems
210 systems
570 - 670 systems
Out of compliance with options for uranium MCL
Uranium at 20 pCi/L (20 ^g/L)
Uranium at 40 pCi/L (40 Mg/L)
Uranium at 80 pCi/L (80 A/g/L)
830 - 970 systems
300 - 430 systems
40- 170 systems
Notes:
Ranges based on directly proportional versus lognoimal distribution approach. Combined radium and gross alpha analyses
include ground water systems only; uranium analysis includes both ground water and surface water systems.
1 . Costs and risk reductions associated with complying with existing requirements for these systems are not assessed because these
impacts are not attributable to the changes in requirements now under consideration.
2. Compared to initial baseline (i.e., occurrence data are adjusted to eliminate illegal noncompliance).
3. Compared to revised baseline (i.e.. occurrence data are adjusted to eliminate legal noncompliance with both gross alpha and
combined radium MCLs).
As indicated by the exhibit, closing the monitoring loopholes will affect about 310 to 400
systems once potential double-counting is taken into account, and the MCL revisions for gross alpha
and combined radium will affect a total of about 570 to 670 systems. The low end estimates
generally result from the direct proportions approach to estimating occurrence, while the lognormal
approach leads to higher estimates of the number of systems out of compliance for most (but not all)
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the options . The uranium options will affect between 40 and 970 systems depending on the MCL
lected and the approach used to estimate the number of systems out of compliance.
In Exhibit ES-2 and ES-3 below, we summarize the risk reductions and compliance costs
suiting from closing the regulatory loopholes for gross alpha and combined radium to eliminate
jal noncompliance with the current regulations. We also report the impacts associated with
:ernative MCLs. Exhibit ES-2 provides the results for the direct proportions approach, while
:hibit ES-3 provides the results for the lognormal approach.
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Exhibit ES-2
SUMMARY OF QUANTIFIED ANNUAL COSTS AND BENEFITS:
DIRECT PROPORTIONS APPROACH
(community water systems)
Total Cancer Cases
Avoided
(fatal cases)
Value of Avoided Cases
(range)
Total Change in
Compliance Costs
Compliance with existing MCLs after closing monitoring loopholes (combined radium = 5 pCi/L, gross
alpha = 15 pCi/L)1
Eliminate gross alpha
monitoring loophole only
Eliminate combined radium
monitoring loophole only
Eliminate both loopholes2
0.04 cases total
(0.03 fatal)
0.31 cases total
(0.21 fatal)
0.32 cases total
(0.22 fatal)
S0.2 million
($<0.1 - $0.3 million)
SI. 2 million
(S0.3 - S2.4 million)
$1.3 million
($0.3 - $2.5 million
$2.5 million
$21.6 million
$22.2 million
Compliance with revised MCL options 3
Revise gross alpha MCL to 1 0
pCi/L net of radium-226 only
Limit radium-228 at 3 pCi/L
within combined radium MCL
ofSpCi/Lonlv
Revise both gross alpha and
radium MCLs2
0.53 cases total
(0.35 fatal)
0.50 cases total
(0.34 fatal)
0.78 cases total
(0.52 fatal)
S2.1 million
($0.5 - $4.0 million)
$2.0 million
($0.5 - $3.9 million)
$3.1 million
($0.8 - $6.0 million)
$62.7 million
$40.7 million
$82.5 million
Compliance with new uranium MCL options
Establish uranium MCL at 20
pCi/L (20 Mg/L)
Establish uranium MCL at 40
pCi/L (40 /zg/L)
Establish uranium MCL at 80
pCi/L (80 Mg/L)
0.15 cases total
(0.10 fatal)
0.04 cases total
(0.02 fatal)
0.01 cases total
(<0.01 fatal)
$0.6 million
($0.2 -$1.2 million)
$0.1 million
($<0.1 - $0.2 million)
$<0.1 million
$31.6 million
$6.7 million
$5.0 million
Notes:
See text for discussion of non-quantified impacts and limitations in the analysis.
Gross alpha and combined radium risk estimates include risk reductions due to incidental treatment; e.g., the removal of gross
alpha by treatments installed to address combined radium and vice-versa.
1. Compared to full compliance baseline (i.e.. occurrence data are adjusted to eliminate illegal noncompliance).
2. Removes double-counting of systems affected by both options.
3. Compared to revised baseline (i.e.. occurrence data are adjusted to eliminate legal noncompliance).
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Exhibit ES-3
SUMMARY OF QUANTIFIED ANNUAL COSTS AND BENEFITS:
LOGNORMAL DISTRIBUTION APPROACH
(community water systems)
Total Cancer Cases
Avoided
(fatal cases)
Value of Avoided
Cases
(range)
Total Change in
Compliance Costs
Compliance with existing MCLs after closing monitoring loopholes (combined radium = 5 pCi/L, gross
alpha = 15 pCi/L)1
Eliminate gross alpha monitoring
loophole only
Eliminate combined radium
monitoring loophole only
Eliminate both loopholes2
0.35 cases total
(0.22 fatal)
0.54 cases total
(0.37 fatal)
0.86 cases total
(0.57 fatal)
$1.3 million
($0.3 - $2.6 million)
$2.2 million
($0.6 - $4.3 million)
$3.4 million
($0.9 - $6.6 million)
$34.5 million
$38.8 million
$7 1.9 million
Compliance with revised MCL options3
Revise gross alpha MCL to 10 pCi/L
net of radium-226 only
Limit radium-228 at 3 pCi/L within
combined radium MCL of 5 pCi/L
only
Revise both gross alpha and radium
MCLs2
0.70 cases total
(0.45 fatal)
0.63 cases total
(0.43 fatal)
1.08 cases total
(0.72 fatal)
$2.7 million
($0.7 - $5.2 million)
$2.6 million
($0.7 - $5.0 million)
$4.3 million
($1.1 - $8.3 million)
$7 1.6 million
$37.9 million
$83.7 million
Compliance with new uranium MCL options
Establish uranium MCL at 20 pCi/L
(20Mg/L)
Establish uranium MCL at 40 pCi/L
(40 Mg/L)
Establish uranium MCL at 80 pCi/L
(80 Mg/L)
2.12 cases total
(1.37 fatal)
1 .54 cases total
(l.OOfatal)
1 .03 cases total
(0.67 fatal)
$8.2 million
($2.1-$15.8 million)
$6.0 million
($1.5 -$11. 6 million)
$4.0 million
($1.0 -$7.7 million)
$157.0 million
$68.0 million
$29.9 million
Notes:
See text for discussion of non-quantified impacts and limitations in the analysis.
Gross alpha and combined radium risk estimates include risk reductions due to incidental treatment; e.g., the removal of gross
alpha by treatments installed to address combined radium and vice-versa.
1 . Compared to full compliance baseline (i.e., occurrence data are adjusted to eliminate illegal noncompliance).
2. Removes double-counting of systems affected by both options.
3. Compared to revised baseline (i.e., occurrence data are adjusted to eliminate legal noncompliance).
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As indicated by the exhibits, most of the regulatory options would change the statistical risks
of incurring fatal or nonfatal cancers by less than two cases per year; many options lead to reductions
of less than one case. In general, fatal cases are roughly two-thirds of the total cases avoided. The
best estimate of the value of these risk reductions ranges from less than $0.1 million to slightly over
$8.0 million annually, depending on the regulatory option considered and the approach used to
estimate occurrence. Compliance costs range from $2.5 million to over $150 million annually. The
options with the lowest and highest costs vary depending on the approach used for estimating
occurrence. While in most cases the lognormal approach leads to higher costs and larger risk
reductions, in a few cases the lognormal estimates are lower because of the distribution of the
underlying data.
Although these results are preliminary and subject to uncertainty, they suggest that the
regulatory options under consideration may have costs in excess of benefits in all cases, if only
quantified costs and benefits are considered. However, when all of the sources of uncertainty are
taken into account, EPA believes that costs may exceed benefits by a much smaller amount than
indicated by the above exhibits, and for some options costs and benefits may be relatively equal.
EPA plans to conduct more research as well as develop a probabilistic model to reduce, and better
quantify, the effects of these uncertainties.
The cost estimates assume that systems will often install treatment to comply with the MCLs,
while recent research suggests that in reality they generally select less costly options such as
blending water from contaminated and uncontaminated sources. Selection of such options may
reduce compliance costs significantly. The benefits associated with risk reductions may be
understated because the analysis does not consider the effects of treatment on other contaminants
present nor does it include the effects of uranium on the kidneys. (There are also substantial
uncertainties in the risk models used to estimate the coefficients used in this analysis.) In addition,
the benefits analysis does not consider other impacts such as improvements in the aesthetic qualities
of the water (taste, odor, color) or reduced material damages associated with the treatment or other
actions undertaken to comply with the new requirements.
The analysis also does not quantify other impacts that will have more uncertain effects on
the relationship between costs and benefits. For example, it does not quantify the impacts of the
regulatory options on systems serving populations more than one million (information collected to-
date suggests that few, if any of these systems may be affected by the regulations). It also does not
include cost or risk reduction estimates for non-transient non-community systems, which EPA plans
to address in more detail in an Addendum to this report.
EPA also plans to conduct more research on other topics not addressed in detail in this report.
For example, the preliminary analysis also does not consider the impact of the regulations on other
programs, such as the use of MCLs in site clean-up decisions. In addition, it does not quantify the
impacts of the regulatory options on certain groups of concern, such as health risks posed to children,
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members of low income or minority groups, or sensitive sub-populations. It also does not address
unfunded mandates or options for minimizing costs for small systems. All of these factors are of
interest to decision-makers and will be taken into account in the final selection of the regulatory
options to be implemented.
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INTRODUCTION AND REGULATORY FRAMEWORK CHAPTER ONE
The U.S. Environmental Protection Agency (EPA) is considering changes to the regulations
governing the allowable levels of radionuclides in drinking water. The Notice of Proposed
Rulemaking for these revisions was published in 1991. Since that time, additional information on
the impacts of changes to these standards has become available. EPA has chosen to publicize this
information through a Notice of Data Availability, which summarizes the risks and costs potentially
associated with revisions to the standards. This report provides more detailed information on these
impacts.
This introductory chapter provides background information on the current and proposed
radionuclides regulations. It then discusses federal requirements for the economic analysis of new
or revised drinking water standards, and presents an overview of the preliminary analysis contained
in this report. The subsequent chapters and appendices discuss the analytic approach and results in
more detail.
REGULATORY OPTIONS
EPA first promulgated standards regulating the concentrations of radionuclides in drinking
water in 1976 as National Interim Drinking Water Regulations (see 40 CFR 141). In 1986, EPA
published an Advance Notice of Proposed Rulemaking, which discussed additional information on
the occurrence of radionuclides in drinking water, as well as the associated risks. The Notice of
Proposed Rulemaking (NPRM) for revisions to the radionuclide standards was published in 1991.
The Notice of Data Availability (NODA) that this report supports provides additional information
on the topics addressed by that NPRM.
The current regulations establish Maximum Contaminant Levels (MCLs) of 5 pCi/L for
radium-226 and radium-228 combined, and of 15 pCi/L for gross alpha (net of uranium and radon).1
1 The NODA also addresses changes to the MCL for beta and photon emitters. This
preliminary analysis does not consider the effects of these changes because EPA expects that the
national impacts will be relatively small.
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In the 1991 NPRM, EPA proposed to revise the combined radium and gross alpha standards and to
create an MCL for uranium. Separate, higher standards were proposed for radium-226 and radium-
228, while the standard for gross alpha would remain the same but be redefined to exclude radium-
226.
As discussed in the NOD A, EPA believes that the proposed changes to the gross alpha and
combined radium MCLs are no longer appropriate. Hence those changes are not assessed in this
report. Instead, EPA is interested in providing information on the costs and risk reductions
associated with limiting the contribution of radium-228 to the current combined radium MCL, and
with lowering the gross alpha MCL but excluding radium-226 from its definition. In both the 1991
proposal and the NODA, EPA also considers whether it is appropriate to establish an MCL for
uranium, and this report provides updated information on the potential impacts of alternative
uranium MCLs. The MCL options addressed by each of these efforts are summarized in Exhibit 1 -1.
Exhibit 1-1
ALTERNATIVE REGULATORY LEVELS
Radionuclide
Combined radium-226
and radium-228
Gross alpha
Uranium
Current MCL
5 pCi/L
15pCi/L,
net of uranium and radon
None
1991 Proposed MCLs
20 pCi/L for radium-226;
20 pCi/L for radium-228
15pCi/L,
net of radium-226,
uranium, and radon
20 Mg/L (20 pCi/L)
MCL Options
Assessed in this Report
5 pCi/L, limiting the
contribution of radium-228
to 3 pCi/L
lOpCi/L,
net of radium-226, uranium,
and radon
20 //g/L (20 pCi/L);
40 //g/L (40 pCi/L);
80 Mg/L (40 pCi/L)
Note:
These analyses assume a one-to-one mass-to-activity level ratio for the uranium options. The NODA provides
information on alternative ratios, which are also discussed in Chapter 2 of this report.
Sources:
Current MCLs: U.S. Environmental Protection Agency, "National Primary Drinking Water Regulations," 40 CFR
141.15.
1991 Proposed MCLs: U.S. Environmental Protection Agency, "National Primary Drinking Water Regulations,
Radionuclides, Notice of Proposed Rulemaking," 36 FR 33050, July 18, 1991.
MCL Options: U.S. Environmental Protection Agency, "National Primary Drinking Water Regulations,
Radionuclides. Notice of Data Availability," forthcoming.
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In addition to revising the MCLs, EPA is considering whether to alter the requirements for
monitoring and analysis. The existing regulations include inadvertent loopholes that allow systems
to "legally" exceed the current MCLs. These loopholes are as follows:
Under 40 CFR 141.26(a)(l)(i), systems may avoid analyzing their water for
compliance with the combined radium standard if the measured gross alpha activity
level is reliably below 5 pCi/L.2
Under 40 CFR 141.26(a)(l)(ii), systems may avoid measuring radium-228 in cases
where radium-226 does not exceed 3 pCi/L.
Under 40 CFR 141.26, systems may hold their gross alpha samples long enough to
allow radium-224 to decay below detection limits.
Under the first two loopholes, some systems may legally exceed the MCL of 5 pCi/L for combined
radium because the regulations allow them to avoid measuring activity levels for radium-228.3
Under the third loophole, systems with elevated levels of radium-224 may legally exceed the MCL
of 15 pCi/L for gross alpha because of the length of the allowable holding time for the samples.
EPA is considering various options for closing these loopholes to ensure that all systems achieve
radionuclide levels at or below the existing MCLs.
In addition to changing the MCLs and the monitoring requirements, EPA is considering
whether to extend these requirements to non-transient non-community water systems. The current
regulations apply only to community water systems. The regulations (at 40 CFR 141.2) define a
community water system as "a public water system which serves at least 15 service connections used
by year-round residents or regularly serves at least 25 year round residents." A non-transient, non-
community water system is defined as "a public water system that is not a community water system
and that regularly serves at least 25 of the same persons over 6 months per year." These systems
often serve locations such as schools or office buildings.
REQUIREMENTS FOR ECONOMIC ANALYSIS
EPA is required to assess the costs, benefits, and other impacts of major regulations by a
number of statutes and administrative orders. These requirements have changed significantly since
EPA published the 1991 proposal for revisions to the radionuclides regulations. General guidance
for economic analysis was developed by the Office of Management and Budget (OMB) in 1996 for
2 Under certain conditions, states may lower this cut-off to 2 pCi/L.
3 Radium-228 is a beta emitter, whereas radium-226 is an alpha emitter and included in the
measurement of compliance with both the gross alpha and combined radium MCLs.
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all Federal agencies, and EPA is now finalizing its own more detailed guidance on these issues. In
addition, there are several new statutory and administrative requirements for assessing the
distribution of costs and benefits and equity concerns, focusing on groups such as small businesses
and children. The Safe Drinking Water Act (SDWA) Amendments of 1996 also include new
requirements for the analysis of regulations establishing MCLs.
The preliminary analysis documented in this report is consistent with the general
requirements for economic analysis, and will be supplemented as needed by additional analyses to
support the final rulemaking. Proposed and final regulations promulgated under SDWA are subject
to three sets of general requirements for economic analysis.
The 1996 SDWA Amendments impose significant new requirements for assessing the
benefits and costs of drinking water standards. Specifically, when proposing an MCL, EPA must
publish an analysis of the benefits and costs of compliance with the MCL, including discussion of
issues such as: (1) the quantifiable and non-quantifiable health risk reductions of controlling the
regulated contaminants as well as co-occurring contaminants; (2) the quantifiable and non-
quantifiable costs of compliance with the proposed MCL; (3) the incremental costs and benefits
associated with each alternative MCL under consideration; and, (4) the effects of the contaminant
on the general population and on groups that are likely to be at greater risk of adverse health effects
(i.e., sensitive sub-populations). The analysis must also consider other factors such as the quality
of the available information and uncertainties in the analysis, and the degree and nature of the
identified risks [SDWA, Section 1412(b)(3)(C)(i)]. SDWA also requires the Agency to consider the
impacts of the regulations on small water systems, and includes provisions addressing affordability
and criteria for variances or exemptions [SDWA Sections 1412(b), 1415(e), 1416].
OMB's 1996 Guidance for implementing Executive Order 12866 (on "Regulatory Planning
and Review") requires Federal agencies to conduct economic analyses of significant regulatory
actions as a means to improve regulatory decision-making. Significant regulatory actions include
those that may "(1) [h]ave an annual effect on the economy of $100 million or more or adversely
affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the
environment, public health or safety, or State, local, or tribal governments or communities; (2)
[cjreate a serious inconsistency or otherwise interfere with an action taken or planned by another
agency; (3) [mjaterially alter the budgetary impact of entitlements, grants, user fees, or loan
programs or the rights and obligations of recipients thereof; or (4) [r]aise novel legal or policy issues
arising out of legal mandates, the President's priorities, or the principles set forth in this Executive
Order."4
4 Executive Order 12866, "Regulatory Planning and Review," September 30, 1993; U.S.
Office of Management and Budget, Economic Analysis of Federal Regulations Under Executive
Order 12866, January 11, 1996.
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As outlined in the OMB guidance, analyses of these actions should be designed to provide
information for decision-makers on the potential benefits to society of alternative regulatory and
non-regulatory approaches to risk management in comparison to potential costs, recognizing that not
all benefits and costs can be described in monetary or even in quantitative terms. The guidance also
focuses on ensuring that decisions are based on the best available scientific, technical, and economic
information. The specific topics addressed include determining whether federal regulation is
warranted, examining alternative regulatory and non-regulatory approaches, and assessing the
benefits, costs, and other impacts of the alternatives.
EPA's Guidelines for Preparing Economic Analyses, which provide substantially more
detailed information on the topics introduced in OMB's guidance, are now being updated and
finalized.5 The draft EPA guidelines discuss the statutory and executive order requirements for
conducting economic analyses; the procedures and analyses used to identify the environmental
problem to be addressed and justify federal intervention; the regulatory and non-regulatory
approaches to consider; and the theoretical foundation for environmental economic analyses. The
EPA guidelines also provide detailed information and guidance on baseline specification, social
discounting, and treatment of uncertainty; on assessment of benefits, social costs, economic impacts
and equity effects; and on the use of economic analyses in decision-making.
The three sets of requirements noted above each discuss the need for analysis of
distributional impacts and equity concerns. In addition, consideration of these types of concerns is
required by the following statutes and executive orders.6
The Unfunded Mandates Reform Act of 1995 (UMRA) requires that the government
consider the costs and benefits of any proposed or final rule that includes a Federal mandate
resulting in the "expenditure by State, local and tribal governments, in the aggregate, or by
the private sector, of $100,000,000 in any 1 year" [UMRA Section 202(a)]. Title II of
UMRA directs agencies to prepare an economic analysis that assesses: the anticipated
benefits and costs of the mandate; the extent to which federal resources and financial
assistance are available to offset the costs imposed; any disproportionate budgetary effects
on any particular geographic area or sector; and any effects on the national economy.
5 U.S. Environmental Protection Agency, Guidelines for Preparing Economic Analyses:
Review Draft, June 1999.
6 These and other statutes and executive orders also include requirements that apply to the
regulatory development process (e.g., for consultation with representatives of the groups of concern).
The discussion in this section focuses solely on the requirements for economic analysis.
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The Regulatory Flexibility Act of 1980. as amended by the Small Business Regulatory
Enforcement Fairness Act of 1996 (SBREFA/RFA) requires agencies to evaluate the
impacts of the reporting, record-keeping, and other compliance requirements imposed on
small entities, and to consider regulatory alternatives and other measures that can minimize
these impacts while accomplishing the stated objectives of the applicable statutes. Analysts
may first conduct a screening analysis to determine if effects on small entities are significant.
A detailed analysis is not required if the agency can certify that the rule "will not, if
promulgated, have a significant economic impact on a substantial number of small entities."
Federal Actions to Address Environmental Justice in Minority Populations and Low
Income Populations (Executive Order 12898; 1994) refers to the desire to avoid
disproportional adverse effects on minority and low income groups. While the Executive
Order and associated guidance do not outline specific requirements for economic analyses,
they discuss the need to consider whether such effects may be significant.
Protection of Children from Environmental Health Risks and Safety Risks (Executive
Order 13045; 1997) requires agencies to provide "...(a) an evaluation of the environmental
health or safety effects of the planned regulations on children; and (b) an explanation of why
the planned regulation is preferable to other potentially effective and reasonably feasible
alternatives considered by the agency."
In addition to these requirements for analyses of effects on certain groups of concern, the
Paperwork Reduction Act requires that EPA submit an Information Collection Request to OMB for
approval prior to promulgating regulations containing information collection requirements. This
request must describe and justify the requirements and discuss the use of the resulting data. The
request must include estimates of the burden (i.e., labor hours) and dollar costs associated with the
information collection requirements.
This preliminary analysis focuses on the national impacts of the regulations and is consistent
with the above guidance applicable to this type of assessment. It does not assess distributional
impacts or equity concerns in detail, although relevant information is provided both in this report
and in the other documents referenced in the NODA. EPA plans to address these concerns in more
detail prior to development of the final rule.
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COMPARISON TO 1991 ANALYSIS
The analysis reported in this document differs from the analysis conducted in 1991 in many
ways.7 As noted earlier, the 1991 analysis considers different regulatory options and was written
prior to implementation of several new requirements for regulatory impact analysis. In addition, the
1991 report does not separate the effects of non-compliance with the existing regulations from the
effects of changes to these regulations. The Agency also has refined the approach for assessing the
occurrence of radionuclides, developed better estimates of compliance costs, created a new cost
model, and altered its estimates of the risks associated with ingestion of individual radionuclides.
Because the 1991 analysis considers different regulatory options and does not separately
assess the impacts of non-compliance with the current regulations, it is difficult to compare the two
analyses and to come to any general conclusions about the effects of the changes in analytic
approach. However, EPA believes that the analysis reported in this document provides a more
realistic picture of the costs and benefits of the options. It reflects several years of research on
related issues and implements many enhancements to the data and analytic approach used in each
part of the analysis. The following sections provide an overview of this approach, which is
described in more detail in the following chapters.
GENERAL APPROACH
The analysis in this report represents the work completed to date in the development of a
comprehensive economic analysis for the radionuclides rule, as required under the statutes, executive
orders, and EPA guidance discussed above. It provides preliminary estimates of national costs and
benefits, and presents information on the data sources and analytic approach used for review by
interested stakeholders. This analysis subsequently will be refined as needed to respond to
comments, incorporate new data, and provide additional assessments of uncertainty in the estimates.
In addition, it will be expanded to include analysis of distributional effects (e.g., on small systems
and children) as required by various statutes and administrative orders.
The basic steps in a comprehensive economic analysis are illustrated in Exhibit 1 -2 and
include the following:
7 Wade Miller Associates, Incorporated, Regulatory Impact Analysis of Proposed National
Primary Drinking Water Regulations for Radionuclides, prepared for the U.S. Environmental
Protection Agency, July 17, 1991.
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1. Estimate baseline conditions: This step involves estimating current and future
conditions in the absence of the revised rule. It includes identifying and characterizing the
potentially affected universe (e.g., those community and non-community water systems
required to comply with the rule) and determining the contaminant levels likely if no new
regulations are promulgated.
2. Predict responses to the new regulations: The second step in the analysis involves
predicting the responses of the regulated community to the new regulations. Typically,
analysts assume that water systems will select the least cost compliance option. In the case
of the radionuclides rule, these options may include installing various treatment technologies
(such as water softening), installing point-of-use devices (i.e., home water treatment
devices), or switching water sources (e.g., drilling new wells in uncontaminated areas or
purchasing water from another system).
3. Estimate changes in national costs: The third step is to determine the total national
costs attributable to the new regulations. The conceptually correct approach to estimating
these costs includes consideration of market impacts (e.g., decreases in water consumption
due to price increases). However, in cases where market effects are likely to be small,
analysts often simply sum compliance costs nationally.
4. Estimate changes in national benefits: The fourth step in the analysis involves
estimating the national benefits of the new regulations. For drinking water regulations, these
benefits primarily include reduced risks to human health, but may also include reduced
damages to materials (e.g., pipe corrosion), improved aesthetics (taste, odor, color), or
reduced ecological risks. For radionuclides, the primary benefits are reductions in cancer
risks; other beneficial health effects (particularly reductions in kidney damage from exposure
to uranium) are also possible.
5. Assess distributional impacts: While Steps 3 and 4 focus on the national effects of the
regulations, decision-makers and stakeholders are also interested in the effects of the
regulations on specific groups, such as small water systems or sensitive sub-populations
(e.g., children). As discussed earlier, analyses of these concerns are required by statute and
administrative order. These distributional analyses may consider the costs and/or the
benefits of the regulations for the groups of concern.
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Exhibit 1-2
MAJOR COMPONENTS OF A COMPREHENSIVE ECONOMIC ANALYSIS
Estimate baseline
conditions
Predict responses to
new regulations
Estimate changes in
national costs
Estimate c
national
Assess distributional
impacts
In this report, we develop preliminary estimates of national costs and benefits, focusing on
monitoring and compliance costs and reductions in cancer risks. Other national costs and benefits
(e.g., state administrative costs and risk reductions from treatment of co-occurring contaminants) and
potential distributional impacts are described qualitatively in this report as well as in other
documents supporting the NODA. As noted earlier, EPA plans to conduct further analysis of these
issues prior to finalizing the revised radionuclides regulations.
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BASELINE DEFINITION
The first step in the economic analysis, defining the baseline, provides unusual challenges
in the case of the radionuclides regulations. Several community water systems are not complying
with the existing regulations for gross alpha and combined radium, in part because they are
anticipating the proposed changes in these requirements and hope to avoid unnecessary costs. Also,
as discussed earlier, there are loopholes in the current monitoring requirements that allow some
systems to legally avoid compliance with the current MCLs. To address these issues, this
preliminary analysis sequentially considers two baselines.
Initial baseline: Under this scenario, we assume that all systems will ultimately
comply with the existing regulations as currently written. Community water systems
would be required to achieve the current MCLs except in cases where they can
legally avoid compliance due to the loopholes in the monitoring requirements.
Revised baseline: Under this scenario, we assume that EPA would alter the current
regulations to eliminate the monitoring loopholes, so that all community water
systems would be required to achieve the existing MCLs.
This dual baseline approach allows us to separate the costs and benefits of changes in the monitoring
requirements from the costs and benefits of changes in the MCLs. It also avoids attributing costs
to the new regulations that are in fact attributable to achieving compliance with the regulations now
in force.
The steps in the preliminary national benefit-cost analysis are illustrated in more detail in
Exhibit 1-3. First, we develop the initial baseline, under which some systems may be legally out of
compliance with the existing MCLs. We use this baseline to assess the risk reductions and costs
associated with closing the monitoring loopholes. This step leads directly to the revised baseline,
under which all systems must be at or below the existing MCLs. We use this revised baseline to
estimate the incremental risk reductions and costs associated with changes to the MCLs. The
analysis is conducted sequentially so that the costs and benefits of changing the MCLs can be added
to the costs and benefits of closing the monitoring loopholes to assess the total impact of potential
changes to the regulations.
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Exhibit 1-3
INITIAL AND REVISED BASELINES
Initial Baseline; Some systems may
"legally" exceed existing MCLs. .
Close Monitoring
Loopholes; Eliminate
legal noncompliance; calculate
associated risk
reductions and costs.
Revised Baseline; All systems must be
at or below the existing MCLs.
Change MCLs;
Calculate risk reductions
and costs associated with
options for changing
MCLs.
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The analysis of the risk reductions and costs associated with changes to the standards for
radionuclides in drinking water consists of three inter-related components. The first involves
estimating the occurrence of radionuclides under the baseline scenarios, including the frequency with
which radionuclide concentrations are likely to exceed levels of concern. The second component
involves determining the potential changes in risks associated with the regulatory options, focusing
on the risks of incurring fatal and nonfatal cancers. The third component consists of estimating the
costs associated with changes to the regulatory requirements, including the costs associated with
monitoring and analysis as well as treatment or other options for complying with the MCLs. The
following chapters discuss each of these topics for community water systems, describing our analytic
approach, the results of the analysis, and its limitations and implications. These chapters are
followed by a discussion of the impacts on non-transient non-community water systems.
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BASELINE OCCURRENCE CHAPTER TWO
In this chapter, we discuss the prevalence and concentrations of radionuclides in water
provided by community systems in the absence of changes to the existing regulations.1 The analysis
involves estimating radionuclide concentrations under the initial baseline (assuming full compliance
with the regulations as currently written) and then under the revised baseline (assuming the
regulations are altered to close existing monitoring loopholes and eliminate legal exceedences of the
current MCLs). Below, we first discuss our approach to the analysis; we then present our findings
and their limitations.
ANALYTIC APPROACH
The approach for the occurrence analysis includes three separate components. First, we
begin by extrapolating from data obtained through EPA's National Inorganics and Radionuclides
Survey (NIRS).2 We use two different extrapolation methods, one based directly on the NIRS
proportions and a second that fits a lognormal probability distribution to the NIRS data. Second, we
adjust the data to address compliance issues and develop initial and revised baselines for the
analysis. Because NIRS does not include very large systems (those serving one million or more
people), the third component of the analysis entails using other data sources to provide information
on baseline occurrence levels for these systems.
1 See Chapter 5 for a discussion of non-transient non-community water systems.
2 Beginning in late 1999, water systems were required to develop Consumer Confidence
Reports that provide data on water quality. Over the next several months, we plan to review a
sample of these documents to determine whether reported occurrence levels differ significantly from
the data and assumptions used in this preliminary analysis.
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NIRS Data
The most comprehensive source of nationwide estimates of radionuclide concentrations in
drinking water is the National Inorganics and Radionuclides Survey (NIRS).3 NIRS is a national
survey designed to estimate the occurrence of various contaminants in finished drinking water from
community ground water systems in the United States. To conduct the survey, EPA selected a
random sample of 1.000 community ground water systems, stratified into four population size
classes, from the inventory of 47,700 public water systems reported in the Federal Reporting Data
System in 1983. The researchers collected water samples from 990 of these systems from 1984 to
1986, and tested them for occurrence of radium-226, radium-228, uranium, and gross alpha as well
as other contaminants.
As indicated in Exhibit 2-1 below, most of the NIRS systems sampled served relatively small
populations (less than 3,300 persons).4 For comparison, the exhibit also reports the number of
ground water systems now operating in each of the size classes, based on validated December 1997
data from EPA's Safe Drinking Water Information System (SDWIS).5 Appendix A provides more
detailed information from SDWIS on the number of systems and populations served by size class,
ownership and water source.
3 Jon P. Longtin, "Occurrence of Radon, Radium, and Uranium in Groundwater," Journal
of the American Water Works Association, July 1988; Jon P. Longtin, "Occurrence of Radionuclides
in Drinking Water, A National Study," Radon, Radium and Uranium in Drinking Water, (C. Richard
Cothern and Paul A. Rebers, eds.), Chelsea, Michigan: Lewis Publishers, 1990.
4 The data reported in Exhibit 2-1 reflect the final NIRS database used in this analysis. The
number of systems in each size strata in the original sample are reported in the Longtin articles cited
above.
5 We exclude systems classified as "other" ownership from this exhibit because the 1997
SDWIS validation effort indicates that these systems are probably inactive. We also exclude systems
serving fewer than 25 people because they do not meet the definition of public water systems subject
to the regulations. Of the 42,781 systems included in the exhibit, 1,918 rely on purchased water.
These systems are included to ensure that the populations they serve are addressed in the analysis
(available data on populations served includes retail populations only). Ground water systems
reported as under the influence of surface water (327 systems nationally) are included in the surface
water system data because they tend to have similar contamination problems. Systems serving more
than one million persons are assessed separately.
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Exhibit 2-1
RELATIONSHIP BETWEEN EPA AND NIRS SIZE CATEGORIES
EPA System Size Classes
Population Served
25- 100
101 -500
501 - 1,000
1,001 -3.300
3,301 - 10,000
10,001 -50,000
50,001 - 100,000
100,001 - 1,000,000
Total
Number of Community
Ground Water Systems
Operating
(SDWIS, 1997)
28,502
10,319
2,472
1,488
42,781
NIRS Stratification
Population Served
<; 500
501 -3,300
3,301 - 10,000
> 10,000
Total
Number of Community
Ground Water Systems
Sampled
(NIRS, 1984-1986)
675
233
54
28
990
Sources:
1 997 SDWIS data: International Consultants, Incorporated, Drinking Water Baseline Handbook: First Edition
(draft), prepared for the U.S. Environmental Protection Agency, March 2, 1999, Table B4.1.1(a).
1984 - 1986 NIRS data: lEc analysis of final NIRS database provided by David Huber, EPA/OGWDW, January 8,
1999.
For this analysis, we adjust the NIRS data to address certain of its limitations. These
limitations include: (1) the small size of the sample for systems serving populations greater than
3,300 persons; (2) the decay of radium-224 prior to analysis of the NIRS water samples; (3) the need
to convert mass measurements of uranium to activity levels; (4) the lack of information on surface
water systems; and, (5) the relationship between the NIRS data and the actual national distribution
of occurrence levels. Our approach for addressing each of these issues in the preliminary analysis
is discussed below. The implications of uncertainties associated with our analytic approach are
discussed at the end of this chapter.
Systems Serving Populations of 3,300 to 1,000,000: Due to time and funding constraints,
the NIRS researchers could sample only a limited number of systems. They chose to stratify their
sample so that it was proportional to the actual number of community ground water systems
operating in each size class. For example, about 71 percent of the systems operating in 1985 served
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25 to 500 people, and about 71 percent of the sites in the original NIRS sample served populations
in this size category. As a result of this stratification, very few systems (82 total) serving
populations greater than 3,300 were included in the final sample.
This small sample size may mean that the systems included in NIRS are not representative
of the systems operating nationally in these size classes. Statistical theory suggests that a sample
of 200 systems or more would be needed to provide reasonably accurate and reliable estimates for
systems in each of the two larger size classes, whereas the sample sizes for the smaller size classes
may be adequate.
Data collected by EPA suggest that larger systems tend to have better water quality than
smaller systems. For example, SDWIS data suggest that systems serving small populations more
frequently exceed the existing radionuclides MCLs than do systems serving larger populations.6
If we divide the number of 1997 gross alpha violations in SDWIS by the estimated number of sites
(e.g., individual wells) operated by systems relying on ground water, we find that 0.13 to 0.14
percent of the sites may be in violation for systems serving populations of 3,300 or less. This figure
drops to 0.08 to 0.09 percent for systems serving between 3,301 and 100,000 persons, and to 0.03
percent for systems serving more that 100,000 persons. The frequency of combined radium
violations show a similar pattern: 0.20 to 0.26 percent of the sites may be in violation for systems
serving populations of 3,300 or less; 0.17 to 0.11 percent may be in violation for systems serving
between 3,301 and 100,000 persons; and less than 0.01 percent may be in violation for systems
serving more that 100,000 persons. Investigation of SDWIS data for other years shows similar
relationships between system size and violation rates.7
This relationship between system size and water quality is also suggested by data on other
contaminants. For example, EPA's 1989 analysis of alternative MCLs for inorganic chemicals
6 Analysis of SDWIS data conducted by William Labiosa of EPA/OGWDW (September 9,
1999). This comparison is provided for illustrative purposes only. Information reported to SDWIS
may be inconsistent and incomplete; some violations may be reported multiple times while others
may not be reported at all. In addition, the methods used to estimate the number of sites used by
ground water systems may be inconsistent with the definition of compliance points used in SDWIS
reporting.
7 The reporting of fewer violations by large systems may be due in part to their ability to react
immediately to potential water quality problems (for example by blending water from different
sources, changing the operation of their treatment plant, or closing affected wells) without having
to report a violation or purchase capital equipment.
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indicates that occurrence of inorganic chemicals is negligible in the larger system size categories.8
Systems serving over 50,000 persons generally implement more sophisticated and extensive
treatment processes, conduct more comprehensive monitoring, have more options for immediately
addressing water quality problems, and use operators with higher levels of expertise than smaller
systems. As a result, inorganic chemicals tend to occur at lower levels in larger systems.
Due to the concerns about the small number of systems sampled for the larger size classes
in NIRS, this preliminary analysis uses data on systems in the smaller size classes to estimate
occurrence levels for larger systems. Specifically, we assume that the frequency of non-compliance
will be the same in systems serving 3,301 to one million persons as in systems serving 501 to 3,300
persons. For example, if one percent of the systems in the 501 - 3,300 size class would be out of
compliance with a particular regulatory level, we assume that one percent of the systems serving
3,301 - one million persons also would be out of compliance. This approach may overstate the
extent to which concentrations exceed levels of concern in the larger systems, given the likelihood
that water quality improves as system size increases.
Decay of Radium-224: Radium-224 is an alpha emitter with a 3.66 day half-life. If a water
system does not analyze its samples quickly (i.e., within three days), it will not detect concentrations
of radium-224 that may be present in drinking water at the point of use. Because the existing
regulations allow water systems to hold their samples for long time periods, radium-224 is not likely
to be detected.9 Depending on whether a composite sample is prepared, the holding time under the
existing regulations can range from six to 12 months. Systems with significant radium-224 levels
therefore may be in "legal noncompliance" status, since the existing regulations allow them to hold
their samples until radium-224 decays below detection limits.
8 Wade Miller Associates, Incorporated, Regulatory Impact Analysis: Benefits and Costs of
Proposed National Primary Drinking Water Regulations for Inorganic Chemicals, prepared for the
U.S. Environmental Protection Agency, March 31, 1989. Because many of the treatment
technologies used to remove inorganic chemicals from drinking water supplies (e.g., lime softening,
ion exchange, reverse osmosis, activated alumina) are the same as those commonly used for
radionuclides removal, effective treatment of inorganics may also reduce radionuclide concentrations
in finished water.
9 EPA has recommended that states require more timely analysis of gross alpha samples, but
has not promulgated this recommendation as a regulation. We are uncertain about the extent to
which this approach it has been implemented by the states. See: Memorandum to Water
Management Division Directors, Regions 1-X, from Cynthia C. Dougherty, Director, Office of
Ground Water and Drinking Water, "Recommendations Concerning Testing for Gross Alpha
Emitters in Drinking Water," January 27, 1999.
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It appears that the NIRS samples were held long enough to allow radium-224 to decay below
detection limits. Most of the NIRS samples were shipped directly to the Technical Support Division
of the Office of Drinking Water in Cincinnati, Ohio, via two-day express service, while the quality
assurance samples were shipped via express service to the Eastern Environmental Radiation Facility
in Montgomery, Alabama.10 Upon receipt of the samples, the two facilities logged the sample
information into a data management system, ensured that pH levels of the samples were stabilized
at less than 2.0, and distributed the samples to the appropriate laboratory for analysis. The NIRS
researchers indicate that at least one month elapsed before the samples were analyzed."
To assess the effect of changing the monitoring requirements to mandate more timely
analysis, we estimate the levels of radium-224 likely to be detected based on a study that the U.S.
Geological Survey (USGS) is currently conducting. This study considers the correlation between
the occurrence of radium-224 and radium-228 in samples from approximately 100 ground water
systems.12 The analysis found that there tends to be a one-to-one ratio between occurrence of
radium-228 and radium-224. When the daughter products of radium-224 are taken into account, the
effect on the level of gross alpha emitters measured is to add three times the radium-228 level.
Hence to estimate the effects of capturing radium-224 in the analysis, we add the value of radium-
228 multiplied by three to the gross alpha levels reported in NIRS.
For example, if a system reports radium-228 occurrence at 2 pCi/L and gross alpha
occurrence at 12 pCi/L, we would add 6 pCi/L (2 pCi/L * 3) to the gross alpha level to reflect the
presence of radium-224 and its daughter products, for a total gross alpha level of 18 pCi/L (12 pCi/L
+ 6 pCi/L). A system with these values technically would be in compliance with the existing gross
alpha standard of 15 pCi/L (because 12 pCi/L is less than 15 pCi/L) under the current monitoring
requirements. If the requirements were changed to require more timely analysis, such a system
would exceed the current MCL (because 18 pCi/L is above 15 pCi/L).
Uranium Mass-to-Activity Ratio: In NIRS, uranium levels were reported in mass units (as
Aig/L). For the economic analysis, we need to translate these values to measures of radioactivity
(pCi/L) for two reasons. First, the uranium MCLs under consideration by EPA would limit both
mass and activity levels. Second, the regulatory definition of gross alpha excludes both radon and
10 Jon P. Longtin, "Occurrence of Radon, Radium, and Uranium in Groundwater," Journal
of the American Water Works Association, July 1988.
1' Personal communication between David Huber, EPA/OGWDW and Richard J. Velton,
March 29, 1999.
12 Personal communication between Michael Focazio, EPA and Zoltan Szabo, USGS,
February 18, 1999.
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uranium, while the gross alpha values reported in NIRS (in pCi/L) exclude radon but include
uranium. Hence, we must subtract the uranium values from the gross alpha values as reported in
NIRS to determine whether the system exceeds the regulatory levels for gross alpha.
Analysis conducted by EPA indicates that the mean mass-to-activity ratio is approximately
1.3 pCi per ng across all uranium samples assessed.13 However, if only samples with uranium
activity levels greater than 3.4 pCi/L are considered, the mean ratio drops to 0.9 pCi per fj.g. Most
of the uranium values reported in NIRS would be below this level (i.e., below 3.4 pCi/L) regardless
of which mass-to-activity ratio is used; however, we are most concerned with the systems reporting
values above the MCLs under consideration. For this preliminary analysis, we apply a mass-to-
activity level of 1:1 both in adjusting the reported gross alpha values to exclude uranium and in
assessing the uranium MCL options.
Surface Water Systems: The NIRS data do not address radionuclide concentrations in
surface water, and other data sources do not provide comprehensive or representative national
estimates of radionuclide concentrations in finished water from surface water sources. Hence, for
this preliminary analysis, we use information from other studies to determine how to best extrapolate
from the NIRS ground water activity levels to surface water levels.
Based on the available literature, we assume that radium-226, radium-228, and gross alpha
do not occur above levels of concern in surface water sources.14 The studies we reviewed indicate
that the radium content of surface water is usually very low. Because gross alpha levels are often
comprised largely of radium-226, we also assume that occurrence of alpha emitters at levels of
concern in surface water is rare. For example, for systems included in the NIRS sample serving 501
- 3,300 persons, radium-226 is on average approximately 39 percent of the gross alpha values.
Therefore, the analysis of regulatory options for combined radium and gross alpha considers only
systems relying primarily on ground water sources.
Furthermore, we assume that uranium occurrence in surface water is one-third of the level
reported in ground water. This ratio results from research conducted by Oak Ridge National
13 Memorandum from J. Scott Telofski, National Air and Radiation Environmental
Laboratory, to David Huber, EPA/OGWDW, "Maximum Contaminant Level for Uranium in
Drinking Water," March 25, 1999.
14 C. T. Hess, J. Michel, T. R. Horton, H. M. Prichard, and W. A. Coniglio, "The Occurrence
of Radioactivity in Public Water Supplies in the United States," Health Physics, Vol. 48, No. 5, May
1985, page 553; Jacqueline Michel, "Relationship of Radium and Radon with Geological
Formations." Chapter 7 in C. R. Cothern and P. A. Rebers, eds., Radon, Radium, and Uranium in
Drinking Water, 1990, page 83.
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Laboratory (ORNL).15 In analyses of 55,433 U.S. ground water samples and 34,561 U.S. surface
water samples, ORNL found that the average concentration of uranium was 3.18 pCi/L in ground
water and 1.06 pCi/L in surface water (these data are for raw water, not finished drinking water
supplies). The median concentration rafiges from these samples were 0.2 to 0.5 pCi/L for ground
water and 0.1 to 0.2 pCi/L for surface water. Based on these ranges, the ratio of ground water
occurrence to surface water occurrence varies from 1:1 to 5:1, with an average of 3:1. Using either
mean or median results therefore leads to an average ratio of ground water occurrence to surface
water occurrence of 3:1.
Extrapolation to National Estimates: In this preliminary analysis, we use two different
approaches to estimate national occurrence levels based on the NIRS data. The first approach
assumes that radionuclide occurrence nationally is exactly in proportion to the NIRS results. For
example, if two percent of the NIRS systems in a particular size class would require a removal rate
of between 30 and 50 percent to comply with a specific MCL, we assume that two percent of the
systems nationally in that size class would require the same removal rate.
The second approach recognizes that actual occurrence will be spread over a wider range,
and that some systems will report values in-between (and above and below) the values reported in
NIRS. Inspection of the NIRS data (see Appendix B) suggests that it is distributed in a roughly
lognormal pattern, with most systems reporting concentration levels below the MCLs of concern.
Several other studies also suggest that the distribution of radionuclide occurrence in drinking water
systems is likely to follow a lognormal distribution.16 Thus, under the second approach, we use a
statistical software package (Stata) to estimate a lognormal distribution that best fits the data for
systems in each size class. We then use the log means and log standard deviations of the resulting
distributions to estimate the number of systems out of compliance with each regulatory option.
The difference between these two approaches is illustrated by the hypothetical example in
Exhibit 2-2. The lognormal distribution follows the pattern of the bars (which indicate the
15 Oak Ridge National Laboratory, Uranium in U.S. Surface, Ground, and Domestic Waters,
Volume 1, prepared for the U.S. Environmental Protection Agency, April 1981; R. C. Cothern and
W. L. Lappenbusch, U.S. Environmental Protection Agency, Office of Drinking Water, "Occurrence
of Uranium in Drinking Water in the U.S." Health Physics, Vol. 45, No. 1., pp. 89-99, July 1983.
16 See, for example, Jon P. Longtin, "Occurrence of Radon, Radium, and Uranium in
Groundwater," Journal of the American Water Works Association, July 1988; and, Wade Miller
Associates, Incorporated, Addendum to the Occurrence and Exposure Assessments for Radon,
Radium-226, Radium-228, Uranium and Gross Alpha Particle Activity in Public Drinking Water
Supplies (Draft), prepared for the U.S. Environmental Protection Agency, September 3, 1993,
Appendix.
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proportions extrapolated directly from NIRS), but spreads systems more evenly over the continuum
of possible concentration levels. It also often tends to push systems into the right tail of the
distribution (i.e., to lead to higher estimates of occurrence for those systems most out of
compliance). However, the exact relationship between the direct proportion and lognormal estimates
depends on the underlying NIRS data, and is indicated by the estimates reported in the "Findings"
section of this chapter.
Exhibit 2-2
HYPOTHETICAL ILLUSTRATION OF
DIRECT PROPORTIONS VS. LOGNORMAL
Percent
of
Systems
MCL
Occurrence Level (pCi/L)
Kev:
= direct proportions
= lognormal
Initial and Revised Baselines
As discussed in Chapter 1, some community water systems are not complying with the
existing MCLs for combined radium and/or gross alpha. This noncompliance may be "illegal" if the
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system is not following the requirements in the current regulations. Alternatively, it may be "legal"
because the existing regulations include some loopholes in the monitoring requirements that allow
systems to avoid analyzing for the presence of certain radionuclides.
To address these issues, we first develop an initial baseline for combined radium and gross
alpha that reflects full compliance with the existing regulations as written. This approach assumes
that, in the absence of changes to the regulations, all systems will eventually fully comply with the
existing regulations. This approach allows us to separate out the effects of different types of
noncompliance from the effects of changes to the MCLs. Second, we develop a revised baseline that
adjusts the data to reflect closure of the monitoring loopholes, and use this baseline to assess the
incremental impacts of changing the MCLs.
These baseline adjustments are not applied to uranium, which is not currently regulated.
While the treatments installed to eliminate illegal and legal noncompliance with the gross alpha and
combined radium MCLs may also affect uranium, we do not quantify these impacts in this
preliminary analysis. We make no adjustment for two reasons. First, the NIRS data suggest that
systems with elevated levels of gross alpha or combined radium rarely report uranium concentrations
above levels of concern.17 Second, some types of treatment used to remove gross alpha or radium
are less effective in removing uranium, and hence will have little impact on occurrence levels.
The adjustments (discussed below) that we make to estimate each baseline are summarized
in Exhibit 2-3.
I7This finding is consistent with information on the conditions under which each radionuclide
tends to occur at elevated levels: radium tends to occur at higher levels in areas with low dissolved
oxygen and high total dissolved solids, while uranium tend to occurs at higher levels in oxygen-rich
waters with low total dissolved solids (Zapecza, O.S. and Z. Szabo, "Natural Radioactivity in
Groundwater A Review," US Geological Survey National Water Summary 1986, Ground-water
Quality: Hydrologic Conditions and Events, US Geological Survey Water Supply Paper 2325,1987,
pp. 50 - 57). EPA has also studied the co-occurrence of radium-226, uranium-235, and uranium-
238; however, the number of samples assessed was too small to be representative of national
conditions. (Science Applications International Corporation, Co-Occurrence of Drinking Water
Contaminants: Primary and Secondary Constituents - Draft Report, prepared for the U.S.
Environmental Protection Agency, May 21, 1999.)
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Exhibit 2-3
BASELINE ADJUSTMENTS
Initial Baseline
Revised Baseline
If system is out of compliance with
existing regulations, adjust combined
radium and gross alpha values to
eliminate illegal noncompliance.
No changes for other systems
If system exceeds existing MCLs due to
the monitoring loopholes, adjust
combined radium and gross alpha values
to eliminate legal noncompliance.
No changes for other systems
Initial Baseline Compliance under Current Monitoring Requirements
Developing the initial baseline for gross alpha and combined radium involves a series of
steps to eliminate illegal noncompliance. Because both gross alpha and combined radium are
removed by the same treatment techniques, the adjustments we make for gross alpha are
accompanied by adjustments in the combined radium values, and vice-versa. The steps for making
these adjustments are described below; the assumptions used in these steps (e.g., for the ratio of mass
to activity levels and the presence of radium-224) are discussed in the previous section. Steps A.I
through A.4 are used under both the direct proportions and lognormal approaches described earlier;
developing the lognormal estimates requires one additional step, as discussed under Step A. 5.
Step A.1: Identify Systems in Illegal Noncompliance with Gross Alpha MCL: We first
adjust the NIRS data to be consistent with the regulatory definition of gross alpha by subtracting the
reported values for uranium from reported values for gross alpha.18 We then determine whether the
18 In this and all other adjustments, NIRS values reported as "below the minimum reporting
level (MRL)" are treated as one-half of the MRL. The MRLs are 2.6 pCi/L for gross alpha, 0.08
/zg/L for uranium, 0.18 pCi/L for radium-226, and 1.0 pCi/L for radium-228. Hence, for example,
a uranium value reported as below the MRL would be treated as 0.04 /^g/L when subtracting the
uranium values from the reported gross alpha values, or 0.04 pCi/L assuming a 1:1 ratio between
mass and activity levels.
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resulting gross alpha value for each NIRS system is above the current MCL (15 pCi/L), excluding
any adjustment for radium-224. If yes, we flag the system as in illegal noncompliance.
Step A.2: Identify Systems in Illegal Noncompliance with Combined Radium MCL:
Second, we determine whether systems are illegally out of compliance with the combined radium
MCL of 5 pCi/L, taking into account the monitoring loopholes in the existing regulations. Due to
these loopholes, systems are in illegal noncompliance status only if: (1) they report gross alpha
levels above 5 pCi/L; (2) they report radium-226 levels above 3 pCi/L; and, (3) the sum of radium-
226 and radium-228 exceeds 5 pCi/L.
Step A.3: Estimate Post-Compliance Gross Alpha and Combined Radium Levels: For
those systems in illegal noncompliance status for either gross alpha or combined radium, we use the
removal rates from EPA's cost model (discussed in Chapter 4) to estimate post-compliance activity
levels.19
In the case where a system is illegally out of compliance for both radium and
gross alpha, we assume that the system will install treatment with a removal
rate that achieves compliance for both MCLs. For example, if a system
requires a 30 percent removal rate to achieve gross alpha compliance and a
50 percent removal rate to achieve radium compliance, we assume it will
install treatment to achieve a 50 percent removal rate.
For systems in illegal compliance with only the gross alpha or the combined
radium MCL (not both), we assume that the treatment installed will reduce
the occurrence of both groups of radionuclides because the types of
technologies installed are generally effective in removing both gross alpha
and combined radium. For example, if a system is illegally out of
compliance for gross alpha (but not for combined radium) and requires a
removal rate of 80 percent to achieve the gross alpha MCL, we reduce
radium-226 and radium-228 levels (as well as gross alpha levels) by 80
percent.20
19 The removal rates used are 30, 50, 80, or 95 percent. We apply the lowest of these rates
needed to reach the MCL, which in most cases leads to post-compliance activity levels below the
MCL.
20 Actual removal rates for the co-occurring contaminants will vary depending on influent
concentrations and other factors.
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Step A.4: Estimate Radium-224 Levels and Add to Gross Alpha: Because closing the
monitoring loopholes will require systems to conduct more timely analysis to detect the presence
of radium-224 and its daughter products, we add three times the adjusted value for radium-228 (i.e..
the radium-228 value that results from Steps A.I through A.3 above) to the adjusted value for gross
alpha. Under the direct proportions approach, the data resulting from this step are used to estimate
the proportion of systems legally out of compliance with the current MCLs.
Step A.5: Estimate Lognormal Distributions: Under the lognormal approach, the final
step in the analysis involves estimating lognormal probability distributions that best fit the data that
results from Step A.4. The log means and log standard deviations from these distributions are then
used to estimate the percentage of systems legally out of compliance with the current MCLs.
The resulting data provide the initial baseline for the analysis. Under this baseline, some
systems will legally exceed the current gross alpha and combined radium MCLs. These data are the
input to the cost and risk analysis completed to assess the effects of changes to the monitoring
requirements, since such changes will eliminate legal noncompliance and require all systems to
achieve concentration levels below the MCL.
Revised Baseline Compliance under New Monitoring Requirements
To develop the revised baseline for gross alpha and combined radium, we begin with the
initial baseline estimates discussed above, and then adjust them to reflect closure of the monitoring
loopholes and elimination of legal noncompliance with the existing regulations.21 The result of this
step is that all systems are at or below the current MCLs of 15 pCi/L for gross alpha (net of uranium
and radon and including radium-224) and 5 pCi/L for combined radium-226 and radium-228.22 This
step provides us with the full compliance occurrence estimates that are used to assess changes to the
gross alpha and radium MCLs. Again, the initial steps (Steps B.I through B.4) are undertaken for
both the direct proportions and lognormal approaches described earlier; the lognormal distributions
are then estimated as part of Step B.5.
21 Note that this adjustment assumes that EPA will close the monitoring loopholes for both
gross alpha and combined radium. The results would be slightly different if EPA decides to close
only one of the loopholes. The number of systems affected by each loophole is reported in the
"Findings" section of this chapter.
22 Under the lognormal approach, a small fraction of the systems will exceed the MCL
because we did not truncate the right tail of the distribution at the existing MCL (see illustration in
Exhibit 2-2). However, this fraction represents very few systems, each of which exceeds the MCL
by a very small amount; therefore, we expect this issue will have a negligible impact on our results.
2-13 U.S. EPA Headquarters Library
Mail code 3201
1200 Pennsylvania Avenue NW
Washington DC 20460
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Industrial Economics, Incorporated: January- 2000 Draft
Step B.I: Identify Systems in Legal Noncompliance with Gross Alpha MCL: First, we
determine whether the gross alpha value resulting from Steps A. 1 through A.4 above exceeds the
current MCL (15 pCi/L) when radium-224 and its daughter products are included. If yes, we flag
the system as in legal noncompliance.
Step B.2: Identify Systems in Legal Noncompliance with Combined Radium MCL:
Next, we determine whether the combined radium-226 and radium-228 value resulting from Steps
A.I through A.4 above exceeds the current MCL (5 pCi/L) once the monitoring loopholes are closed.
If yes, we flag the system as in legal noncompliance.
Step B.3: Estimate Post-Compliance Gross Alpha and Combined Radium Levels: For
those systems in legal noncompliance status for either gross alpha or radium, we again use the
removal rates from EPA's cost model to estimate post-compliance activity levels. As in the analysis
of the initial baseline, if a system is legally out of compliance for both radium and gross alpha, we
assume that it will install treatment to achieve the highest removal rate needed. Also consistent with
the analysis of the initial baseline, we estimate the effects of treatment for gross alpha on radium
occurrence levels and vice-versa by applying the same removal rates to the data on gross alpha,
radium-226, and radium-228 to estimate post-compliance occurrence. The data that results from this
step is used to assess the combined radium MCL option under the direct proportions approach.
Step B.4: Subtract Radium-226 From Gross Alpha Levels: Because EPA is considering
changing the definition of gross alpha to exclude radium-226, we next subtract the radium-226 value
from the gross alpha value that results from the above steps. The estimates that result from this step
are used to assess the gross alpha MCL option under the direct proportions approach.
Step B.5: Estimate Lognormal Distributions: Under the lognormal approach, the final
step in the analysis involves estimating lognormal probability distributions that best fit the data that
results from the above steps. Because the combined radium MCL under consideration limits the
contribution of radium-228 to the total (but does not change the MCL), we estimate the radium
distributions based solely on the radium-228 data from Step B.3. For gross alpha, the distributions
are based on the data from Step B.4. The log means and log standard deviations from these
distributions are then used to estimate the percentage of systems out of compliance with the
alternative MCLs.
Systems Serving Populations Greater than One Million
The NIRS sample does not include any systems serving populations of greater than one
million. These systems tend to be unique in many respects due to their large size. Therefore, rather
than extrapolating from the smaller system size classes, we reviewed data on 16 individual systems
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to determine whether they might be affected by the regulatory changes EPA is considering.23 We
obtained data from system water quality reports, most of which are posted on the Internet. In a few
cases, we followed up with individual water systems to request published reports that were more
detailed than those available electronically. In the near future, we plan to conduct additional
research to fill in remaining data gaps.
In analyzing the data, we make several assumptions that relate largely to determining whether
the systems are in "legal non-compliance" status due to the loopholes in the existing monitoring
requirements. First, we assume that systems are not analyzing gross alpha samples quickly enough
to detect radium-224 before it decays to below detection limits, and that the reported gross alpha
values therefore exclude radium-224. We also assume that when systems report combined radium
occurrence as "not detected" (rather than reporting radium-226 and radium-228 separately), it means
that both radium-226 and radium-228 occurrence is below detectable limits. In other words, we
assume that such systems have not used the monitoring loopholes to avoided analyzing for both
radionuclides.24 In addition, some systems report occurrence data for each of their plants, while
other systems report a single value for each MCL. In the latter case, we assume that no plants within
the system exceed the single value reported. Finally, uranium data are lacking for many systems
because it is not currently regulated; we therefore use data from another source to determine whether
the system is located in a state with potentially elevated uranium levels.25
FINDINGS
Below, we present the results of the occurrence analysis in four sections. First, we address
occurrence of gross alpha and combined radium under the initial and revised baselines. Second, we
describe the occurrence of uranium. Third, we summarize these results. Fourth, we discuss
occurrence in systems serving more than one million people. These sections are followed by a
23 We address 16 systems with retail populations above one million; if wholesale populations
are included, a total of 25 systems exceed this threshold. This focus on retail populations avoids
double-counting with the systems addressed in other parts of the analysis, which include systems
purchasing water from wholesalers. This approach is necessary because the available national data
on populations served addresses only retail populations (see Appendix A).
24 If instead the system reports combined radium as "not reported," we are unsure whether
this reflects use of the monitoring loopholes or other factors (such as receipt of a waiver) that allow
them to avoid reporting.
25 Oak Ridge National Laboratory, Uranium in U.S. Surface, Ground, and Domestic Waters,
Volume 7, prepared for the U.S. Environmental Protection Agency, April 1981.
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discussion of the implications of the limitations of our analysis. Detailed information on the results
for community water systems by system size class are provided in Appendix E, which also provides
the results of the cost analysis.
Gross Alpha and Combined Radium
For gross alpha and combined radium, we assess occurrence under three scenarios. First, we
consider the extent to which systems were illegally out of compliance with the existing requirements
when the NIRS data were collected. Then, we address the extent to which systems exceed the
current MCLs legally (due to loopholes in the current monitoring requirements) after illegal
noncompliance is eliminated. Finally, we assess the extent to which systems are likely to exceed
each of the MCL options under consideration, after both of the monitoring requirements are altered
to ensure full compliance with the existing MCLs. In all cases, we consider only systems relying
primarily on ground water sources, because (as discussed above) we expect that gross alpha and
radium levels will be below levels of concern in systems relying primarily on surface water sources.
Illegal Noncompliance
When the NIRS data were collected in the mid-1980s, some systems were not complying
with the existing regulations in part because they were anticipating regulatory changes. Below, we
discuss the extent of non-compliance at that time, then review more recent date on noncompliance.
NIRS Data: In Exhibit 2-4, we estimate the percent of systems in illegal noncompliance
status nationally based on NIRS. This estimate applies data on the percent of NIRS systems in
illegal noncompliance status (in 1984 -1986) to 1997 data on the number of ground water systems
in each size category. The exhibit first reports the percent of systems out of compliance for each size
class as a fraction of the total systems in that class. It then reports the percentage out of compliance
for all systems in all size classes combined.
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Exhibit 2-4
SYSTEMS ILLEGALLY OUT OF COMPLIANCE WITH EXISTING MCLS
(community ground water systems only)
Regulatory Option
Exceed gross alpha
MCL (15 pCi/L) only
Exceed combined
radium MCL (5 pCi/L)
only
Exceed both gross alpha
and combined radium
MCLs
TOTAL
Notes:
System Size Class
(population served)
25 - 500 persons
501-1 million persons
Subtotal
25 - 500 persons
501-1 million persons
Subtotal
25-500 persons
501-1 million persons
Subtotal
All systems
Percent of Systems
Illegally Out of
Compliance
0.4 percent
0.9 percent
0.6 percent
0.7 percent
0.4 percent
0.6 percent
0.3 percent
0.4 percent
0.3 percent
1.6 percent
Number of Systems
Illegally Out of
Compliance
130 systems
120 systems
250 systems
210 systems
60 systems
270 systems
80 systems
60 systems
150 systems
670 systems
Estimates based on NIRS data collected in 1984 - 1986; may overstate current level of noncompliance.
Detail does not add to totals due to rounding.
As indicated by the exhibit, we estimate that 1.6 percent (about 670 systems) of the
approximately 42,781 ground water systems in these size classes nationally are illegally exceeding
the current MCLs, assuming that the extent of noncompliance has not changed since the NIRS data
were collected. Of this total, we estimate that about 400 systems (250 plus 150) are .in illegal
noncompliance status for gross alpha, and that about 420 systems (270 plus 150) are in illegal
noncompliance status for combined radium. There is some overlap between these two categories;
about 150 systems are in illegal noncompliance status for both MCLs.26
Other sources of noncompliance data: Since the NIRS data were collected, some of these
systems may have complied with the existing standards. This compliance may have resulted from
26 We present these data on illegal noncompliance primarily as background information (we
do not assess related costs or risks since they are attributable to the current regulations), and hence
do not provide alternative estimates using a lognormal distribution.
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the installation of treatment to comply with other recently promulgated regulations, consolidation
with neighboring systems with lower contaminant levels, or in response to the enforcement penalties
(and negative public reactions) associated with continued noncompliance with the radionuclides
standards.27 Below, we discuss data on non-compliance from other data sources. While none of
these sources provide estimates comparable to the NIRS data, they provide insights into current rates
of noncompliance.
We first reviewed violations data from SDWIS. These estimates are not directly comparable
to the NIRS estimates above, in part because they are reported by monitoring location (not by
system), and a system may have several monitoring sites. In addition, some violations are not
reported to SDWIS. However, these data provide some indication of the trends in compliance over
time.
Exhibit 2-5 lists the gross alpha and combined radium violations reported in SDWIS for three
years. In 1997,117 violations of the gross alpha MCL and 189 violations of the combined radium
MCL were reported. While comparison of this 1997 data to the 1987 data suggest that the number
of reported violations may be decreasing, the surge in gross alpha violations in 1992 suggests that
violations may fluctuate from year to year rather than consistently decrease over time.
Exhibit 2-5
SDWIS VIOLATIONS DATA
(for selected years)
MCL
Gross Alpha
Combined Radium
Number of Violations
1987
135 violations
233 violations
1992
236 violations
204 violations
1997
1 17 violations
1 89 violations
Notes:
Violations indicate MCL exceedences at individual monitoring points, of which there may be several within a single
water system. Hence these data are not directly comparable to the data on NIRS systems provided above. In
addition, some violations are not reported to SDWIS.
Source:
Personal communication with William Labiosa, EPA/OGWDW, July 21 , 1999.
27 Since 1984, EPA has promulgated eight final regulations establishing MCLs for numerous
contaminants. Many of these contaminants (e.g., certain inorganic chemicals) require the same
treatment technologies as radionuclides.
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To provide further insights into the extent of illegal noncompliance, we reviewed two
additional data sources. The first is a July 1998 report on the actual cost of compliance with the
radionuclides MCLs, which includes counts of the number of systems illegally out of compliance
with the combined radium MCL in Illinois, Indiana, Ohio, Wisconsin, and Wyoming.28 Data in the
report were collected in early 1998 and may be from years as recent as 1996 to 1997. The second
source of information is a copy of the Illinois Environmental Protection Agency's historical database
of community water systems formerly or currently illegally out of compliance with the current
MCLs for gross alpha and combined radium.29
The five states included in the "Actual Cost" report are among those most likely to report
elevated radium 226 and radium 228 concentrations, according to previous studies of radionuclide
concentrations in raw ground water samples.30 Other areas likely to have elevated levels of
combined radium include parts of Florida, Idaho, California, Colorado, Texas, and the area along
the Southern Appalachian Mountains. We expect that the majority of the violations of the existing
MCLs will occur in these areas.31 The number of systems out of compliance in each state is listed
in Exhibit 2-6.
28 International Consultants, Incorporated, Actual Cost For Compliance with the Safe
Drinking Water Act Standard for Radium 226 and Radium 228 - Final Report, prepared for the U.S.
Environmental Protection Agency. July 1998.
29 Database provided by Dianna Heaberlin of the Illinois Environmental Protection Agency,
July 30, 1999.
30 Michel, J. and M.J. Jordana, "Nationwide Distribution of Radium-228, Radium-226,
Radon-222 and Uranium in Ground Water," Radon, Radium, and Other Radioactivity in Ground
Water: Hydrogeologic Impact and Application to Indoor Airborne Contamination, edited by B.
Graves, Lewis Publishers, Chelsea, Michigan: 1987, pp. 227 - 240.
31 Violations counts from the SDWIS database for the years 1992 to the second quarter of
1999 indicate that, out of a total of 333 violations for combined radium, 152 (46 percent) occur in
Illinois, and 41 (12 percent) occur in Wisconsin. Other states with large numbers of combined
radium violations include Kansas, Missouri, South Dakota, and Texas, with a combined total of 67
violations (20 percent). Again, a system may have more than one SDWIS violation, and not all
systems report to SDWIS. SDWIS data provided by William Labiosa, EPA/OGWDW, August 4,
1999.
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Exhibit 2-6
STATE DATA ON ILLEGAL NONCOMPLIANCE WITH COMBINED RADIUM MCL
(community ground water systems)
State
Illinois'
Indiana
Ohio
Wisconsin
Wyoming
TOTAL FOR FIVE STATES
System Size Class
(population served)
25 - 500 persons
501 - 1 million persons
Subtotal
25 - 500 persons
501-1 million persons
Subtotal
25 - 500 persons
501-1 million persons
Subtotal
25 - 500 persons
501 - 1 million persons
Subtotal
25 - 500 persons
501 - 1 million persons
Subtotal
All System Sizes
Percent of Systems
Reporting Violations
6.5 percent
8.6 percent
7.6 percent
0.5 percent
0.2 percent
0.4 percent
1 .0 percent
none
0.5 percent
0.7 percent
4.4 percent
2.2 percent
0.6 percent
none
0.5 percent
2.9 percent
Number of Systems
Reporting Violations
40 systems
55 systems
95 systems
2 systems
1 system
3 systems
6 systems
none
6 systems
5 systems
19 systems
25 systems2
1 system
none
1 systems
130 systems
Notes:
( 1 ) Illinois data are based on lEc analysis of the Illinois database; the "Actual Cost" report does not include
information on system size classes for this state.
(2) The system size class for one system in violation is unknown.
Sources:
Database provided by Dianna Heaberlin of the Illinois Environmental Protection Agency, July 30, 1999.
International Consultants, Incorporated, Actual Cost For Compliance with the Safe Drinking Water Act Standard for
Radium 226 and Radium 228 - Final Report. Prepared for the U.S. Environmental Protection Agency. July 1998.
In these five states, a total of 130 systems are illegally non-compliant with the current MCL
for combined radium (5 pCi/L), which is about 31 percent of the total of 419 systems predicted by
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NIRS. Because other areas with high combined radium occurrence (not included in this exhibit)
generally have low population densities, and therefore few community water systems, the violations
from these five states may possibly account for the majority of the radium violations in the U.S.
This information, combined with the SDWIS counts of violations, suggests that NIRS may
overestimate the number of systems currently illegally noncompliant with the MCL for combined
radium.
Similar data on gross alpha violations is available only for Illinois.32 Based on the Illinois
database, we are able to calculate the number of systems illegally out of compliance with one or both
of the combined radium and gross alpha MCLs as of January 1, 1999. The results are presented in
Exhibit 2-7.
32 Between 1992 and the second quarter of 1999, 353 violations of the gross alpha MCL were
reported to SDWIS. Seventy-one violations (20 percent) were reported in Illinois, and 136 (39
percent) were reported in Florida. (In contrast, Florida only reported seven out of 333 violations for
the combined radium MCL, as discussed in the footnote above, during the same time period.)
SDWIS data provided by William Labiosa, EPA/OGWDW, August 4, 1999.
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Exhibit 2-7
ILLINOIS SYSTEMS ILLEGALLY OUT OF COMPLIANCE WITH EXISTING MCLS
(community ground water systems only)
Regulatory Option
Exceed gross alpha
MCL(15pCi/L)onlj:
Exceed combined
radium MCL (5 pCi/L)
only
Exceed both gross alpha
and combined radium
MCLs
TOTAL
System Size Class
(population served)
25 - 500 persons
501-1 million persons
Subtotal
25 - 500 persons
501-1 million persons
Subtotal
25 - 500 persons
501 - 1 million persons
Subtotal
All systems
Percent of Systems
Reporting Violations
0.2 percent
0.6 percent
0.4 percent
4.2 percent
4.8 percent
4.5 percent
2.3 percent
3. 7 percent
3.0 percent
8.0 percent
Number of Systems
Reporting Violations
1 systems
4 systems
5 systems
26 systems
31 systems
57 systems
14 systems
24 systems
38 systems
100 systems
Notes:
Detail does not add to totals due to rounding.
Sources:
lEc analysis of data provided by Dianna Heaberlin of the Illinois Environmental Protection Agency, dated July 30,
1999.
Percentages are based on the total number of systems by size class for Illinois as reported in: International
Consultants, Incorporated, Drinking Water Baseline Handbook, First Edition, prepared for U.S. Environmental
Protection Agency, February 24, 1999.
In Illinois, this exhibit shows that about eight percent of all community water systems are
illegally out of compliance with either the combined radium or gross alpha MCL, compared with
the national noncompliance rate of less than two percent in Exhibit 2-4. In addition, about four
percent of the systems in Illinois exceed only the combined radium MCL and three percent exceed
both the gross alpha and combined radium MCLs. These percentages are six to ten times greater
than the proportions reported nationally. This information suggests that Illinois will be
disproportionately affected by efforts to eliminate illegal noncompliance under the existing
regulations.
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Legal Noncompliance
In characterizing the baseline (i.e., radionuclide occurrence in the absence of revisions to the
regulations) we assume that all systems will eventually comply with the current requirements. This
assumption allows us to separate the effects of changes to the regulations (as discussed below) from
the effects of more complete compliance with the existing regulations.
After the adjustment for illegal noncompliance, some systems will legally exceed the current
MCLs because of the monitoring loopholes in the existing regulations (see Exhibit 2-8). The legal
violations of the current MCLs occur because the existing monitoring requirements allow systems
to avoid measuring compliance with the combined radium MCL under certain conditions, and to
hold their samples long enough for radium-224 (a component of gross alpha) to decay below
detection limits.
Exhibit 2-8
EXAMPLE OF ADJUSTMENTS FOR NONCOMPLIANCE
(Direct Proportions Approach)
42,781
ground water
systems
Install treatment to
eliminate illegal
noncompliance
Reduce gross alpha
and radium
concentrations for
667 systems
No adjustment
needed for
remaining systems
Install treatment to
eliminate legal
noncompliance
No further change; below
existing MCLs after initial
adjustment
Reduce gross alpha and radium
concentrations for 314 systems
No adjustment needed for
remaining systems
In Exhibit 2-9, we indicate the percent of systems that are in legal noncompliance status after
we adjust the data to eliminate any illegal noncompliance with the existing standards. We first
report estimates based directly on NIRS, applying our estimates of the percent of systems out of
compliance in each size class to the 1997 validated data on the number of community ground water
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systems in each size class. For comparison, we also present the results based on fitting a lognormal
distribution to the NIRS data, as discussed in the section describing the analytic approach.
Exhibit 2-9
SYSTEMS LEGALLY OUT OF COMPLIANCE WITH EXISTING MCLS
(community ground water systems only)
Regulatory Option
Exceed gross alpha MCL
(ISpCi/Donly
Exceed combined radium
MCL (5 pCi/L) only
Exceed both gross alpha
and combined radium
MCLs
TOTAL
System Size Class
(population served)
25 - 500 persons
501-1 million persons
Subtotal
25-500 persons
501-1 million persons
Subtotal
25 - 500 persons
501-1 million persons
Subtotal
All systems
Number of Systems Legally Out of Compliance
(percent of total)
Directly Proportional
40 systems
(0.1 percent)
none
40 systems
(0.1 percent)
40 systems
(0.1 percent)
60 systems
(0.4 percent)
100 systems
(0.2 percent)
1 70 systems
(0.6 percent)
none
170 systems
(0.4 percent)
310 systems
(0.7 percent)
Lognormal
Distribution
<10 systems
(<0. 1 percent)
80 systems
(0.5 percent)
80 systems
(0.2 percent)
70 systems
(0.2 percent)
70 systems
(0.5 percent)
150 systems
(0.3 percent)
1 70 systems
(0.6 percent)
none
170 systems
(0.4 percent)
400 systems
(0.9 percent)
Notes:
Detail does not add to totals due to rounding.
The extent of overlap ( 1 70 systems) under the lognormal approach is estimated using the direct proportions approach.
These data indicate the number of systems likely to legally exceed the existing MCLs in the
absence of changes to the monitoring requirements in the existing regulations. As indicated by the
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exhibit, we estimate that less than one percent of the 42,781 ground water systems nationally are
legally exceeding either the combined radium or gross alpha MCL. If EPA decides to close only one
of the loopholes, the direct proportions approach indicates that 210 (40 + 170) systems exceed the
gross alpha MCL, while 270 (100 + 170) systems exceed the combined radium MCL. The
lognormal approach increases these estimates to 250 and 320 systems respectively. In total, between
310 and 400 systems may be in legal noncompliance status for one or both of the MCLs.
Compliance with MCL Options
To assess the effects of changes to the MCLs for gross alpha and combined radium, we first
adjust the data to reflect closure of both monitoring loopholes. This step brings all systems fully into
compliance with the existing MCLs, and allows us to separate the effects of changes in the MCLs
from the effects of the monitoring issues.
In this preliminary analysis, we consider two changes in the MCLs: limiting the gross alpha
levels to 10 pCi/L net of radium 226, and limiting the contribution of radium-228 to 3 pCi/L within
the total combined radium MCL of 5 pCi/L.33 In Exhibit 2-10, we indicate the percent of systems
that would be out of compliance with each of these MCL options after we adjust the data to eliminate
all noncompliance with the existing standards. We first report estimates based directly on NIRS;
then, for comparison, present the results based on fitting a lognormal distribution to the NIRS data.
33 In Appendix F, we provide the results of previous analyses that consider the effects of
lower limits on the contribution of radium-228 to the combined radium MCL.
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Exhibit 2-10
SYSTEMS OUT OF COMPLIANCE WITH
GROSS ALPHA AND COMBINED RADIUM MCL OPTIONS
(community ground water systems only)
Regulatory Option
Exceed revised gross
alpha MCL only
(10 pCi/L, net of radium
226)
Exceed revised combined
radium MCL only
(limiting radium-228 to 3
pCi/L, 5 pCi/L total)
Exceed both revised
MCLs (combined radium
and gross alpha)
TOTAL
System Size Class
(population served)
25 - 500 persons
501 - 1 million persons
Subtotal
25 - 500 persons
501 - 1 million persons
Subtotal
25 - 500 persons
501 - 1 million persons
Subtotal
All systems
Number of Systems Legally Out of Compliance
(percent of total)
Directly Proportional
Approach
340 systems
(1.2 percent)
120 systems
(0.9 percent)
460 systems
(1.1 percent)
none
60 systems
(0.4 percent)
60 systems
(0.1 percent)
80 systems
(0.3 percent)
60 systems
(0.4 percent)
150 systems
(0.3 percent)
670 systems
(1.5 percent)
Lognormal Distribution
Approach
250 systems
(0.9 percent)
1 1 0 systems
(0.8 percent)
360 systems
(0.8 percent)
40 systems
(0.1 percent)
30 systems
(0.2 percent)
70 systems
(0.2 percent)
80 systems
(0.3 percent)
60 systems
(0.4 percent)
150 systems
(0.3 percent)
570 systems
(1.3 percent)
Notes:
Detail does not add to total due to rounding.
The extent of overlap (150 systems) under the lognormal approach is estimated using the direct proportions approach.
These data indicate that the number of systems likely to exceed the revised gross alpha MCL
would be more than double the number affected by the potential changes to the combined radium
MCL. If considered independently, the direct proportions approach indicates that about 610 (460
+ 150) systems would exceed the gross alpha MCL option, while 210 (60 + 150) systems exceed the
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combined radium MCL option. The lognormal approach changes these estimates to 500 for gross
alpha, but also estimates that 210 systems will be out of compliance with the combined radium
MCL.34 In total, between 570 and 670 systems may be out of compliance with one or both MCLs,
representing less than two percent of all ground water systems nationally.
Uranium
For uranium, the analysis of occurrence consists of fewer steps. Because uranium is not
currently regulated, there is no need to assess the compliance issues addressed for gross alpha and
combined radium. Rather, we predict noncompliance with the MCL options from the original NIRS
data.35 As discussed earlier, for the preliminary analysis of the uranium options, we assume a one-to-
one mass-to-activity ratio and surface water concentrations at one-third of those of ground water.
In Exhibits 2-11 and 2-12, we indicate the percent of systems that exceed the uranium options
under consideration. In Exhibit 2-11, we apply the percentages derived from NIRS to the 1997
validated data on the number of systems in each size class to estimate the number of systems out of
compliance. Exhibit 2-12 then presents the results fitting a lognormal distribution to the NIRS data.
As indicated in Appendix A, there are approximately 42,781 ground water systems and 10,375
surface water systems operating nationally in these size classes.
34 In some cases, the lognormal approach yields lower estimates than the direct proportions
approach, because clustering of the underlying data near zero "pulls" the distribution lower (i.e.,
towards its left tail).
35 Uranium levels may have changed, however, since the NIRS data were collected. For
example, the NIRS data may overstate uranium concentrations if treatments installed to address other
water quality problems also affect uranium levels.
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Exhibit 2-11
SYSTEMS OUT OF COMPLIANCE WITH URANIUM OPTIONS:
DIRECT PROPORTIONS APPROACH
(community water systems)
Regulatory Option
Exceed MCL of 20
pCi/L (20 ^g/L)
Exceed MCL of 40
pCi/L (40 Mg/L)
Exceed MCL of 80
pCi/L (80 Mg/L)
System Size Class
(population served)
25 - 500 persons
501-1 million
persons
Subtotal
25-500 persons
501-1 million
persons
Subtotal
25 - 500 persons
501-1 million
persons
Subtotal
Number of
Ground Water
Systems
(Percent of Total)
760 systems
(2.7 percent)
60 systems
(0.4 percent)
820 systems
(1.9 percent)
300 systems
(1.0 percent)
none
300 systems
(0.7 percent)
40 systems
(0.1 percent)
none
40 systems
(0.1 percent)
Number of
Surface Water
Systems
(Percent of Total)
<10 systems
(0.1 percent)
none
<10 systems
(<0.1 percent)
none
none
none
none
none
none
Total Number of
Water Systems
(Percent of Total)
760 systems
(2.4 percent)
60 systems
(0.2 percent)
830 systems
(1.6 percent)
300 systems
(0.9 percent)
none
300 systems
(0.6 percent)
40 systems
(0.1 percent)
none
40 systems
(<0.1 percent)
Note:
Detail does not add to totals due to rounding.
As indicated by the exhibit, we estimate that approximately 40 to 830 systems would be out
of compliance with the uranium options under the direct proportions approach. Most of those
affected will be very small ground water systems. Almost no systems would be affected by MCLs
that are less stringent (i.e., higher) than those reported in the exhibit; the highest uranium level
reported in NIRS is 88.2 pCi/L.
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Exhibit 2-12
SYSTEMS OUT OF COMPLIANCE WITH URANIUM OPTIONS:
LOGNORMAL APPROACH
(community water systems)
Regulatory Option
Exceed MCL of 20
pCi/L (20 ^g/L)
Exceed MCL of 40
pCi/L (40 //g/L)
Exceed MCL of 80
pCi/L (80 Mg/L)
System Size Class
(population served)
25 - 500 persons
501-1 million
persons
Subtotal
25 - 500 persons
501-1 million
persons
Subtotal
25 - 500 persons
501-1 million
persons
Subtotal
Number of
Ground Water
Systems
(Percent of Total)
670 systems
(2.3 percent)
250 systems
(1.8 percent)
920 systems
(2.2 percent)
300 systems
(1.1 percent)
110 systems
(0.7 percent)
410 systems
(1.0 percent)
120 systems
(0.4 percent)
40 systems
(0.3 percent)
160 systems
(0.4 percent)
Number of
Surface Water
Systems
(Percent of Total)
20 systems
(0.6 percent)
30 systems
(0.4 percent)
50 systems
(0.5 percent)
10 systems
(0.3 percent)
10 systems
(0.2 percent)
20 systems
(0.2 percent)
<10 systems
(0. 1 percent)
<10 systems
(<0.1 percent)
10 systems
(<0.1 percent)
Total Number of
Water Systems
(Percent of Total)
680 systems
(2.1 percent)
290 systems
(1.3 percent)
970 systems
(1.8 percent)
310 systems
( 1 .0 percent)
120 systems
(0.5 percent)
430 systems
(0.8 percent)
130 systems
(0.4 percent)
40 systems
(0.2 percent)
170 systems
(0.3 percent)
Note:
Detail does not add to totals due to rounding.
For the uranium options, the use of the lognormal approach increases the number of systems
likely to be out of compliance with each MCL option in comparison to the direct proportions
approach. As indicated by the exhibit, we estimate that approximately 170 to 970 systems would
be out of compliance with the uranium options under consideration.
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Summary of Results
In Exhibit 2-13 below, we summarize the results for community water systems reported in
the earlier sections.
Exhibit 2-13
NUMBER OF COMMUNITY WATER SYSTEMS EXCEEDING STANDARDS
Option
Number of
Systems
Illegally out of compliance with existing MCLs (combined radium = 5 pCi/L, gross alpha = 15 pCi/L):
Illegal noncompliance: gross alpha '
Illegal noncompliance: combined radium '
Total number of systems in illegal noncompliance (adjusts for overlap) 2
400 systems
420 systems
670 systems
Legally out of compliance with existing MCLs (due to monitoring loopholes):
Legal noncompliance (due to monitoring loopholes): gross alpha3
Legal noncompliance (due to monitoring loopholes): combined radium3
Total number of systems in legal noncompliance (adjusts for overlap) 2J
2 10 -250 systems
270 - 320 systems
310 -400 systems
Out of compliance with options for revising MCLs:
Gross alpha at 10 pCi/L net of radium 226 *
Combined radium at 5 pCi/L with radium-228 limit at 3 pCi/L *
Total number of systems out of compliance with revised radium or gross alpha MCL
(adjusts for overlap) 2-4
500 - 610 systems
210 systems
570 - 670 systems
Out of compliance with options for uranium MCL:
Uranium at 20 pCi/L (20 Mg/L)
Uranium at 40 pCi/L (40 Mg/L)
Uranium at 80 pCi/L (80 /ag/L)
830 - 970 systems
300 - 430 systems
40 - 170 systems
Notes:
Ranges based on directly proportional versus lognormal distribution approach. Combined radium and gross alpha
analyses include ground water systems only; uranium analysis includes both ground water and surface water systems.
1 . Costs and risk reductions associated with complying with existing requirements for these systems are not assessed
because these impacts are not attributable to the changes in requirements now under consideration.
2. Overlap analysis based on direct proportions approach.
3. Compared to initial baseline (i.e., occurrence data are adjusted to eliminate illegal noncompliance).
4. Compared to revised baseline (i.e., occurrence data are adjusted to eliminate legal noncompliance with both gross
alpha and combined radium MCLs).
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For gross alpha and combined radium, the NIRS data suggest that 670 systems were illegally
out of compliance when the NIRS data were originally collected, if we adjust for double-counting.
More recent data suggest that illegal noncompliance may have decreased somewhat since that time.
Once we adjust the data to eliminate this illegal noncompliance. we estimate that between about 310
and 400 systems will be in legal noncompliance status with one or both of the existing MCLs,
depending the approach used to estimate non-compliance (direct proportions or lognormal
distribution). After the monitoring loopholes are closed, a total of 570 to 670 systems may be out
of compliance with one or both of the options for revising the MCLs for gross alpha and combined
radium. In addition, the MCL options for uranium may affect from about 40 to almost 1,000
systems, depending on the option selected and the approach used to estimate noncompliance. In
general, the estimates of the number of systems out of compliance are higher under the lognormal
approach than under the direct proportions approach.
Systems Serving Populations Greater than One Million
In Exhibit 2-14. we list the 16 systems with retail populations greater than one million, and
summarize the data reviewed to-date on radionuclide concentrations. These data are taken from the
Consumer Confidence Reports provided by each system as of December 1999. In the case of
uranium (which is not currently regulated) we also indicate whether the system is located in an area
of the country with potentially elevated levels if no occurrence data are reported.36 As indicated by
the exhibit, only some systems report actual concentrations for the radionuclides of concern and, in
many cases, the concentrations are reported as below detection limits.37 We are now contacting
selected systems to collect additional information in cases where no data are reported.
36 Areas with potentially elevated levels of uranium were identified based on: Oak Ridge
National Laboratory, Uranium in U.S. Surface, Ground and Domestic Waters, Volume 1, prepared
for the U.S. Environmental Protection Agency, April 1981.
37 Under the existing regulations, the analytical method used to determine compliance with
the gross alpha or combined radium MCL must have a detection limit no greater than 3 pCi/L or 1
pCi/L respectively (40 CFR 141.25(c)(l)).
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Exhibit 2-14
RADIONUCLIDE OCCURRENCE FOR
SYSTEMS SERVING RETAIL POPULATIONS GREATER THAN ONE MILLION
Utility
City of New York DEP*
City of Los Angeles*
Chicago Water Department
Philadelphia Water Department
City of Houston. DPU*
City of Baltimore Bureau of
Water and Waste
City of Atlanta. Bureau of Water
Washington Suburban Sanitary
Commission (Maryland)
San Juan Metropolitano
Miami-Dade Water and Sewer
Department*
East Bay Municipal Utility
District
Phoenix Municipal Water
System*
Cleveland Division of Water
Dallas Water Utilities
City of Detroit Water and
Sewerage Department
Suffolk County Water Authority*
(New York)
Retail
Population
8,000.000
3,515.451
2.800.000
1,600.000
1.608.069
1.600.000
1.500.000
1.497.000
1.429.385
1,355.007
1,200.000
1,140,000
1.135.226
1.039.100
1,027,974
1?017,800
Gross Alpha
Not detected
12 pCi/L or less
1 pCi/L or less
Not detected
9.3 pCi/L or less
Not detected
Not detected
Not detected
Combined
Radium
Not reported
2.7 pCi/L or less
Not reported
Not reported
1 .52 pCi/L or less
Not detected
Not detected
Not detected
Uranium
Not reported
5.7 pCi/L or less
Not reported
Not reported
Not reported**
Not reported
Not reported
Not reported
Not available***
4.8 pCi/L or less
Not detected
9.5 pCi/L or less
3.3 pCi/L or less
Not detected
Not detected
Not detected
Not detected
Not reported
"Not applicable"
Not reported
Not detected
Not detected
Not reported
Notes:
* System relies at least in part on groundwater; other systems rely primarily on surface water (persona
Yvette Selby, EPA/OGWDW, March 5. 1999).
jv'siciii uoes not repOn uranium coiiceiiiiation. out is iccatcu in a state wiin potcuiiany cicvaicu uiaui
National Laboratory. Uranium in U.S. Surface, Ground, and Domestic Waters, Yolume 1, prepared forth
Protection Agency, April 1981).
*** The San Juan system has a waiver that provides exemption from radionuclide monitoring.
Sources:
Population served data: Radon and Arsenic Regulatory- Compliance Costs for the 25 Largest Public
Treatment Plant Configurations), EPA/OGWDW. August 10. 1999.
Concentration data: lEc review of Consumer Confidence Reports available as of December. 1999.
Not reported
Not detected
Not reported**
Not reported
Not reported**
Not reported
Not reported
communication with
uui levels (Oak Ridge
e U.S. Environmental
Water Systems (with
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Because of the limited data available for many systems, it is difficult to quantify their
radionuclide occurrence levels. These data suggest that none of these systems are illegally out of
compliance with the current MCLs. In the case of the gross alpha options, data are not reported on
concentrations of radium-224 (which would be included in the measurement of gross alpha if the
monitoring loophole was closed), and many of the systems do not report an individual value for
radium-226 (which would be netted out of gross alpha to determine compliance with the option of
setting the MCL at 10 pCi/L). However, it appears that three systems (Los Angeles, Phoenix, and
Houston) could possibly have high enough gross alpha levels to be potentially affected by the
regulatory options.
For combined radium, nine of the 16 systems provide data suggesting that they would not
be affected by any of the regulatory options, either because the reported value is below both the
current MCL (5 pCi/L) as well as the potential limit on radium-228 (3 pCi/L), or because these
radionuclides are not detected.38 For the remaining seven systems, the available data are limited.
These systems often do not report values for radium-226 and/or radium-228, and, in many cases, also
do not report values for gross alpha and gross beta (radium-226 is included in the measurement of
gross alpha and radium-228 is included in the measurement of gross beta). More research is needed
to determine radium concentrations for these systems.
Uranium, which is not currently regulated, is addressed by the water quality reports for only
two systems and appears to be well below the regulatory levels under consideration in these cases.
Three additional systems (Phoenix, Dallas, and Houston) are located in states with potentially
elevated uranium concentrations, but their reports do not indicate whether the system itself is likely
to find concentrations above levels of concern.
Despite the lack of concentration data, we expect that few, if any, of these systems would be
significantly affected by the regulatory options under consideration for two reasons. First, most of
these systems rely wholly or in part on surface water sources. As discussed earlier in this chapter,
radionuclides rarely occur at levels of concern in surface water. Second, large systems can often
accommodate small changes in the regulatory requirements relatively easily, because of their ability
to blend contaminated and uncontaminated water sources, adjust existing treatment operations,
and/or discontinue use of the contaminated portion of their supplies. In the near future, we plan to
contact selected systems to determine whether additional information is available on these issues.
38 If the system reports a value for combined radium, rather than separate values for radium-
226 and radium-228, we assume that the value includes both radionuclides (i.e., the system is not
taking advantage of the existing monitoring loopholes).
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IMPLICATIONS OF LIMITATIONS IN THE ANALYSIS
Below we discuss the major limitations of our approach for estimating radionuclide
occurrence, and the extent to which these limitations may lead us to under- or overstate the actual
occurrence of radionuclides in drinking water. In the near future, we plan to collect additional data
to better address these sources of uncertainty.
Factors with indeterminate effects: The analysis of community water supplies relies
heavily on the NIRS data, which has several limitations (discussed earlier in this chapter), including:
(1) the small size of the sample for systems serving populations greater than 3,300; (2) the decay of
radium-224 prior to analysis of the NIRS water samples; (3) the need to convert mass measurements
of uranium to activity levels; and, (4) the lack of information on surface water systems. We are
uncertain whether our adjustments to the NIRS data to address these limitations will lead us to over-
or understate occurrence.
In addition, when we extrapolate directly from the NIRS data, multiplying the sampled
systems by weights indicating the number of systems operating nationally in each size class, we
generally derive lower estimates than when we fit a lognormal distribution to the data. Without
more research into actual occurrence levels, it is difficult to determine the reasonableness of the
resulting ranges due to the other factors leading to uncertainty in the NIRS estimates.
Factors that may lead us to overstate occurrence: The NIRS data are over 10 years old
and may not reflect current conditions. Since the data were collected, EPA has finalized several
rules establishing MCLs, many of which may require treatments that will reduce radionuclide
concentrations. Systems may also have installed treatment (or changed the water sources used) due
to local water quality problems.
In addition, the system counts used in the analysis include both systems that rely on their own
water sources and systems that purchase water from other systems. Because treatment is likely to
be installed at the wholesaler (not by the purchasing system), these counts will overstate the total
number of systems required to install treatment or take other compliance measures by a small
amount. Overall, about five percent of the ground water systems nationally rely on purchased water.
We include these systems because the available data on population served (used in the risk analysis
in Chapter 3) addresses only retail populations; excluding the systems relying on purchased water
would lead us to understate total risk reductions.
Finally, several water systems are in the process of combining to create larger, regional water
systems, and the extent to which this consolidation is being off-set by the creation of new systems
is unclear. By the time that any changes to the radionuclides regulations are implemented, the total
number of systems operating may have decreased below the 1997 estimates used in this analysis.
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Because large systems generally have better water quality than smaller systems (as discussed earlier
in this chapter), consolidation may mean that fewer systems will be out of compliance when the
regulations are implemented.
Factors that may lead us to understate occurrence: As mentioned previously, we adjust
the occurrence data to eliminate legal compliance to isolate the effects of revising the MCLs. In the
analysis, we assume that EPA closes both the gross alpha and the combined radium monitoring
loopholes prior to revising the MCLs. If EPA instead decides to implement only one of these
changes, our analysis may understate the number of systems affected by subsequent changes to the
MCLs by a small amount.
In addition, while we expect that few, if any, of the very large systems (those serving one
million people or more) will be affected by the regulatory options, definitive data are not available
for some systems. We do not include the very large systems in our preliminary quantitative analysis
of benefits and costs; hence this analysis will understate total impacts if some of these systems are
affected.
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RISK REDUCTIONS CHAPTER THREE
This chapter provides estimates of the risk reductions attributable to changes in the regulation
of radionuclides in drinking water supplied by community water systems. We focus on the cancer
risk reductions associated with each regulatory change EPA is considering, and assess the monetary
value of these reductions. As discussed later, the regulations may have other benefits. For example,
treatment installed to reduce radionuclide concentrations will also reduce the concentrations of other
contaminants, leading to additional risk reductions. Decreases in the adverse effects of uranium on
the kidneys are also not quantified. Below, we first discuss our approach to the analysis, then
present our findings and describe their limitations.
ANALYTIC APPROACH
The approach for the risk analysis includes three separate components. First, we develop the
risk factors to be used in the analysis. Second, we apply these risk factors to the data on community
water systems to estimate the risk reductions associated with each regulatory option. Third, we
estimate the dollar value of these reductions in risk. We do not quantify risk reductions associated
with the impacts of the regulatory options on systems serving populations greater than one million
because, as discussed in the previous chapter, the available evidence suggests that few (if any) of
these systems may be significantly affected by the regulatory options under consideration.
Risk Factors
The development of risk factors begins with first determining the appropriate mortality and
morbidity cancer risk coefficients for each radionuclide or group of radionuclides considered in the
analysis; these coefficients indicate the change in lifetime cancer risks associated with ingestion
intake of one unit of activity (e.g., one pCi), averaged over different age categories. Next, we use
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these coefficients to develop factors indicating the individual lifetime risks associated with changes
in exposure, taking into account the amount of water ingested over time.1
The risk factors applied in this analysis represent small changes in an individual's probability
of developing cancer in his or her lifetime. While these probabilities can be summed across a
population to indicate the number of statistical "cases" of cancer avoided, these cases represent the
expected cumulative effects of small changes in risk experienced by a relatively large exposed
population, not actual individual cases.
For each individual radionuclide, EPA developed a coefficient that expresses the estimated
incremental lifetime risk of radiogenic cancer morbidity or mortality per unit activity intake.2 For
this analysis, we use the September 1999 risk coefficients developed as part of EPA's revisions to
Federal Guidance Report 13 (FGR-13).3 FGR-13 compiles the results of several risk models
predicting the cancer risks associated with radioactivity. The cancer sites considered in these models
include the esophagus, stomach, colon, liver, lung, bone, skin, breast, ovary, bladder, kidney,
thyroid, red marrow (leukemia), as well as residual impacts on all remaining cancer sites combined.
The available occurrence data (described in the previous chapter) do not provide information
on the contribution of individual radionuclides or isotopes to the total concentrations of gross alpha
or uranium. Therefore, we cannot apply the individual risk coefficients directly from FGR-13 in
these cases. Our approach to estimating the risk coefficients is described below.
Gross Alpha: Alpha emitters found in drinking water generally result from three natural
decay series, including the radionuclides listed in Exhibit 3-1 below. The exhibit also reports the
risk coefficients for these radionuclides (i.e., the risk of cancer mortality or morbidity per picocurie
(pCi) ingested) from FGR-13.
1 This analysis focuses on changes in cancer risks from tap water ingestion. Individuals may
be exposed to radionuclides in drinking water through other pathways (e.g., inhalation while
showering), and uranium may have toxic effects on the kidneys; however, we expect that any
changes in these types of risks will be significantly smaller than the changes in cancer risks from
ingestion and hence do not quantify them in this preliminary analysis.
. 2 Morbidity indicates total cancer incidence (fatal and nonfatal); mortality indicates the
incidence of fatal cancers.
3 Eckerman, Keith F., Richard W. Leggett, Christopher B. Nelson, Jerome S. Pushkin, and
Allan C.B. Richardson, Cancer Risk Coefficients for Environmental Exposure to Radionuclides,
Federal Guidance Report No. 13 (Draft), September 1999.
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Exhibit 3-1
RISK COEFFICIENTS FOR NATURALLY-OCCURRING ALPHA EMITTERS
Series
Th-232
Th-232
Th-232
Th-232
Th-232
Th-232
U-238
U-238
U-238
U-238
U-235
U-235
U-235
U-235
U-235
Radionuclide
Th-232
Th-228
Ra-224
Po-216
Bi-212
Po-212
Ra-226
Po-218
Po-214
Po-2 1 0 (inorganic)
Po-231
Th-227
Ra-223
Po-2 15
Bi-211
Half Life
1 .4E 1 0 years
1 .9 years
3.66 days
0.15 seconds
61 minutes
3.0E-6 seconds
1 ,600 years
3 minutes
1 .6E-4 seconds
138 days
3.3E4 years
18.7 days
1 1 days
1.8E4 seconds
2.2 minutes
Mortality Risk
Coefficient
(per pCi)
6.92E-11
6.73E-1 1
1.01E-10
NA
5.00E-13
NA
2.65E-10
NA
NA
2.74E-10
NA
2.67E-11
1.48E-10
NA
NA
Morbidity Risk
Coefficient
(per pCi)
1.01E-10
1.07E-10
1.67E-10
NA
7.10E-13
NA
3.85E-10
NA
NA
3.77E-10
NA
4.74E-11
2.38E-10
NA
NA
Notes:
NA indicates that the coefficient is not available.
Lifetime risk coefficients are based on Table 2.2a of the September 1999 draft of Federal Guidance Report No. 13;
becquerels (Bq) are converted to picocuries using a conversion factor of 3.70E-02 Bq/pCi.
Ideally, we would employ a risk coefficient for gross alpha that reflects the actual mix of
alpha emitters in drinking water from those systems affected by each potential regulatory change.
However, sufficient information on the prevalence of the individual alpha emitters is not available.
Instead, we focus on the risk factors for two prevalent alpha emitters: radium-224 and radium-226.
For the preliminary analysis, we use a weighted average value of the risk coefficients for
radium-224 and radium-226 to calculate the cancer risks associated with the changes to the
monitoring requirements for gross alpha. This approach is intended to provide a "central tendency"
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national estimate. As indicated by the above exhibit, individual systems may achieve significantly
different risk reductions if other radionuclides are present.
Based on the occurrence data in Chapter 2, we weight the risk coefficients by the relative
presence of these two radionuclides. The resulting coefficients are used in assessing the affects of
closing the gross alpha monitoring loophole, assuming that no other alpha emitters are present. For
risk reductions associated with changing the gross alpha MCL, we employ the mortality and
morbidity risk coefficients for radium-224 alone because the revised MCL would exclude radium-
226.4
Exhibit 3-2 presents the resulting risk coefficients. The values in the last row of the table,
the weighted averages of the risk coefficients for radium-224 and radium-226, are used in the
analysis of risk reductions associated with decreases in gross alpha concentrations due to closure of
the monitoring loopholes.
Exhibit 3-2
RISK COEFFICIENTS USED IN GROSS ALPHA ANALYSIS
Radionuclide
Ra-224
Ra-226
Half Life
3.6 days
1,600 years
Average Weighted by Relative Prevalence
of Ra-224 and Ra-226
Mortality Risk Coefficient
(per pCi)
1.01E-10
2.65E-10
1.14E-10
Morbidity Risk Coefficient
(per pCi)
1.67E-10
3.85E-10
1.83E-10
Notes:
Lifetime risk coefficients are based on Table 2.2a of the September 1999 draft of Federal Guidance Report No. 73;
becquerels are converted to picocuries using a conversion factor of 3.70E-02 Bq/pCi.
Weighted average values for gross alpha are based on the estimated relative prevalence of these two radionuclides
in systems affected by closure of the monitoring loopholes.
Combined Radium: The approach used to develop risk coefficients for combined radium
is similar to the approach used for gross alpha. To estimate cancer risk reductions from changes to
the monitoring requirements for combined radium, we use a weighted average of the risk coefficients
for radium-226 and radium-228; this weighted average is based the occurrence data presented in
Chapter 2 for those systems legally out of compliance with the combined radium standard. For risk
4 As discussed lin the section on incidental treatment, we also assess the effects of treatment
installed to remove gross alpha on risks from certain other radionuclides present, using the risk
factors appropriate for each radionuclide.
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reductions resulting from limiting the contribution of radium-228 to the MCL, we use the risk
coefficient for radium-228 alone. Exhibit 3-3 below presents the risk coefficients employed in the
preliminary analysis for combined radium.5
Exhibit 3-3
RISK COEFFICIENTS USED IN COMBINED RADIUM ANALYSIS
Radionuclide Half Life
Ra-226 1 ,600 years
Ra-228 5.75 years
Average Weighted by Relative Prevalence
of Ra-226 and Ra-228
Mortality Risk Coefficient
(per PCi)
2.65E-10
7.40E-10
5.66E-10
Morbidity Risk Coefficient
(per pCi)
3.85E-10
1.04E-09
8.03E-10
Notes:
Lifetime risk coefficients are based on Table 2.2a of the September 1999 draft of Federal Guidance Report No
becquerels are converted to picocuries using a conversion factor of 3.70E-02 Bq/pCi.
Weighted average values for combined radium are based on the estimated relative prevalence of these
radionuclides in systems affected by closure of the monitoring loopholes, based directly on the NIRS data.
13;
two
Uranium: To determine the cancer risk coefficients for uranium, we calculate the simple
average of the coefficients for uranium-234, -235, and -238, due to the lack of data on the prevalence
of each isotope in those drinking water supplies potentially affected by each regulatory option. As
shown in Exhibit 3-4, the coefficients for each of these isotopes are similar, so we expect that this
simplified approach will not result in significant under- or over-estimates of risk even though the
three uranium isotopes are prevalent in different proportions than implied by the averaging process.
5 As discussed in the section on incidental treatment, we also assess the risk reductions
attributable to removal of certain other radionuclides by the treatments installed to achieve the
radium standards, using the appropriate risk factors for each radionuclide considered.
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Exhibit 3-4
RISK COEFFICIENTS USED IN URANIUM ANALYSIS
Radionuclide
U-238
U-235
U-234
Half Life
4.5E9 years
7.4E6 years
2.4E5 years
Simple Average for Uranium (U-234,
U-235, U-238)
Mortality Risk Coefficient
(per pCi)
4.18E-11
4.48E-11
4.59E-11
4.40E-11
Morbidity Risk Coefficient
(per pCi)
6.40E-11
6.96E-11
7.07E-11
6.81E-11
Notes:
Lifetime risk coefficients are based on Table 2.2a of the September 1999 draft of Federal Guidance Report No. 13;
becquerels are converted to picocuries using a conversion factor of 3.70E-02 Bq/pCi.
The average values for uranium are simple (unweighted) averages of the risk coefficients for the isotopes listed,
based directly on the NIRS data.
Next, we use the coefficients discussed above to determine lifetime and annual factors that
indicate the cancer risks faced by individuals who ingest tap water. We assume water ingestion
occurs over a life span of 70 years (the estimate of average life expectancy generally used in analyses
of drinking water regulations) and that a year includes 365.25 days on average.
We convert the risk coefficients from FOR-13 into individual risk factors (expressed in terms
of activity concentration per pCi/L of water) by assuming that, on average, an individual consumes
1.12 liters of water per day. This value is an estimate of the mean daily water ingestion rate for the
total U.S. population (all ages), derived by averaging the mean ingestion rate for (1) community
water supplies and (2) all sources (including tap, other, bottled, or missing sources of water). These
two ingestion rates are averaged because the first value may underestimate daily average ingestion
of drinking water from community water supplies since survey respondents may have erroneously
reported consumption of tap water as "missing" or "other" sources. While the second value may be
an overestimate, some of the other sources it includes may be derived from public water supplies.6
For comparison, we also calculate the average individual risk factors using a water ingestion
rate of 2.21 liters per day, based on the average of the 90th percentile values for ingestion from the
same data source. These "high end" factors are not used directly in the preliminary economic
6 Based on EPA recalculation of data from: U.S. Environmental Protection Agency,
Estimated Per Capita Water Ingestion in the United States (Draft), June 1999; provided by John
Bennett of EPA/OGWDW on November 10, 1999.
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analysis (which focuses on providing central tendency estimates), but are taken into consideration
by EPA when developing the regulations to ensure protection of sensitive sub-populations
(consistent with Safe Drinking Water Act (SDWA) Section 1412(b)).
Using these assumptions, we calculate risk factors for both morbidity and mortality in terms
of the change in cancer risks per person per pCi/L. The risk factors presented in Exhibit 3-5 (for
average annual water consumption) are then employed in the following steps in the analysis.
Exhibit 3-5
ESTIMATED INDIVIDUAL RISK FACTORS
(per pCi/L)
Regulatory Option
Morbidity
lifetime
ingestion
annual
ingestion
Mortality
lifetime
ingestion
annual
ingestion
Average Individual Risk Factors, Average Water Consumption (1.12 liters per day)
Gross Alpha: changes in monitoring requirements
(weighted average of Ra-224 and Ra-226)
Gross Alpha: changes in MCL (Ra-224 only)
Combined Radium: changes in monitoring
requirements (weighted average of Ra-226 and
Ra-228)
Combined Radium: changes in MCL (Ra-228 only)
Uranium: establish MCL (simple average of U-234,
U-235, and U-238)
5.24E-06
4.77E-06
2.30E-05
2.98E-05
1.95E-06
7.48E-08
6.81E-08
3.28E-07
4.26E-07
2.79E-08
3.26E-06
2.90E-06
1.63E-05
2.12E-05
1.26E-06
4.65E-08
4.15E-08
2.32E-07
3.03E-07
1.81E-08
Average Individual Risk Factors, 9ffH Percentile Water Consumption (2.21 liters per day)
Gross Alpha: changes in monitoring requirements
(weighted average of Ra-224 and Ra-226)
Gross Alpha: changes in MCL (Ra-224 only)
Combined Radium: changes in monitoring
requirements (weighted average of Ra-226 and
Ra-228)
Combined Radium: changes in MCL (Ra-228 only)
Uranium: establish MCL (simple average of U-234,
U-235, and U-238)
1.03E-05
9.37E-06
4.51E-05
5.85E-05
3.83E-06
1.47E-07
1.34E-07
6.44E-07
8.35E-07
5.47E-08
6.39E*06
5.70E-06
3.19E-05
4.16E-05
2.48E-06
9.13E-08
8.15E-08
4.56E-07
5.95E-07
3.55E-08
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Changes in Occurrence and Exposure
The next steps in the analysis involve applying the individual risk factors from Exhibit 3-5
to the estimates of the reductions in occurrence associated with each regulatory change under
consideration. We use the risk factors for annual ingestion for consistency with the cost analysis
which presents results on an annual basis. The starting point for the analysis is the occurrence data
presented in Chapter 2 of this report. For this preliminary analysis, we apply the categorization
scheme used in EPA's cost model to calculate pre- and post-regulatory occurrence levels (in pCi/L)
and estimate the percentage of systems in each system size category that would be required to
achieve various removal rates under each regulatory option. We next estimate the number of people
served by these systems and apply the risk factors discussed above to predict the risk reductions
attributable to each option. We then assess the additional cancer risk reductions attributable to
incidental treatment of other radionuclides present.
These steps are discussed in detail below. We begin by describing the approach for assessing
the risk reductions associated directly with removal of the regulated radionuclides, then discuss the
approach for assessing the risk reductions associated with the removal of other radionuclides present.
Direct Impacts
To assess the direct effects of each regulatory option on risks, we follow the steps illustrated
in Exhibit 3-6. Appendix A presents the data on populations served that we used in the analysis.
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Analytic Steps:
Stepl
Determine
number of systems in
each size class out-
of-compliance with
regulatory option.
Hypothetical
Step 1
20 systems
in the
25-500 size
class
are out of
compliance.
*
Exhibit 3-6
OVERVIEW OF RISK ANALYSIS
Step 2 Step 3 Step 4 Step 5
Categorize
systems by removal
rate needed to achieve
compliance.
Assume
starting activity level
is at mid-point of
removal range.
Assume
ending activity level
is at maximum
removal for range.
Multiply change in
activity by risk co-
efficient and
population exposed
to estimate risk
reductions.
Example:
/
\
Step 2
/
\
1 5 of these systems
are in the
removal rate
category.
5 of these systems
are in the 50-80
percent
removal rate
category.
Step 3 Step 4 Step S
*
If target MCL is 3
pCi/L. average initial
5 pCi/L, based on 40
percent removal.
If target MCL is 3
pCi/L, average initial
activity level is
8.6 pCi/L, based on 65
percent removal.
>
Ending activity
level is 50 percent
Ending activity
level is 80 percent
lower(l.7pCi/L)
Change in risk = 2.5
pCi/L reduction *
risk factor *
1 5 systems *
average population
served per system.
Change in risk =6.9
pCi/L reduction *
risk factor *
5 systems *
average population
served per system.
Step 1: Using the occurrence data from Chapter 2, we first determine the number of systems
that will be out of compliance with the regulatory option we are examining either closing a
monitoring loophole or adjusting an MCL. These systems are identified in the "Findings" section
of the prior chapter.7
Step 2: We further subdivide these systems by the removal rate needed to achieve
compliance with the regulatory option, based on the occurrence level from the adjusted NIRS data.
The removal rate categories are less than 30 percent removal, 30 to 50 percent, 50 to 80 percent, and
above 80 percent, consistent with the categories used in the cost analysis.
7 This part of the risk analysis follows the same methodology regardless of whether the
occurrence was calculated directly from NIRS or using a lognormal probability distribution.
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Step 3: For each removal rate category, we next estimate the systems' original occurrence
levels by back-calculating from the regulatory level to the mid-point of the removal rate range. (We
use the mid-point to avoid biasing the results.)
For example, as illustrated in Exhibit 3-6, systems categorized as requiring between 30 and
50 percent removal are assumed to require 40 percent removal on average. If the desired occurrence
level (i.e., the target or post-regulatory MCL) is 3 pCi/L, we assume that the original (or baseline)
occurrence level is 5 pCi/L, since a system with occurrence at 5 pCi/L would require 40 percent
removal to achieve compliance with an MCL of 3 pCi/L.
Step 4. For each category, we assume that the removal rate actually achieved is the
maximum for the removal rate category. In other words, we assume the system achieves a higher
level of removal than necessary to meet the MCL on average (e.g., due to the difficulties in fine-
tuning treatments to exactly achieve the regulatory standards and the desire to assure that there is
little chance of occasionally exceeding the MCL). Thus the actual removal rates are assumed to be
30, 50, or 80 percent, or the maximum for the system size category (generally 95 percent).
Continuing with the above example, we assume that these systems (with an original
occurrence level of 5 pCi/L) would install a treatment with 50 percent removal efficiency on average,
thus reducing their actual post-compliance occurrence levels to 2.5 pCi/L (5 * (1 - 0.5) = 2.5). The
resulting change in occurrence, therefore, is 2.5 pCi/L (5 - 2.5 = 2.5) for these systems.
Step 5. Next, we estimate the number of people affected nationally by the reduction in
occurrence and calculate the resulting change in cancer risks. We use data on the populations served
for each size class (in Appendix A) to estimate the average number of people affected per system.
We then multiply the change in activity level by the risk coefficient and by the population exposed
to determine the cancer risks avoided.
For example, if 15 systems in the 25 - 500 size class require between 30 and 50 percent
removal, and these systems serve 158 persons on average, 2,370 people will be affected nationally
by the 2.5 pCi/L reduction calculated above. If the annual risk factor for this regulatory option is
2.0E-6, then this change in exposure will lead to a reduction of 0.01 statistical cancer cases annually.
To determine the total number of statistical cancer cases avoided (morbidity), we perform
these steps for the radionuclides directly addressed by each regulatory option (closing the monitoring
loopholes and adjusting the MCLs) for each system size category and sum the results. We then
repeat these steps to assess mortality risks. To determine the number of nonfatal cases avoided, we
subtract the results for mortality from the results for morbidity.
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Incidental Treatment
After completing the above steps for each individual regulatory' option, we assess the
incidental effects of treatment on other radionuclides present. As discussed in Chapter 2, we
estimate radionuclide occurrence based on two different approaches. First, we assume that national
occurrence is directly proportional to the occurrence levels found in the NIRS database. Second, we
fit a lognormal distribution to the NIRS data and estimate national occurrence based on this
distribution. For this preliminary analysis, we estimate co-occurrence of radionuclides based only
on the direct proportions approach. We then use this estimate to determine the incremental effect
of removal of other radionuclides under both the direct proportions and lognormal approaches. In
other words, if the direct proportion approach leads us to estimate that incidental treatment increases
risk reductions by 0.1 case annually, we assume incidental treatment will also increase risk
reductions by 0.1 case under the lognormal approach.
Consistent with the assumptions elsewhere in this analysis, we continue to assume that
treatment to remove gross alpha is equally effective in removing combined radium and vice-versa.
Furthermore, we assume that treatment for radium and gross alpha has a negligible effect on uranium
levels and vice-versa. This latter assumption is based on our finding that uranium often does not
occur at levels of concern in systems that also have elevated levels of gross alpha or combined
radium. In addition, treatments installed to remove uranium are not always as effective in removing
alpha emitters or radium.8
The approach for assessing these impacts varies depending on the assumptions regarding
which regulatory options ultimately will be implemented. We first discuss the analysis of incidental
treatment assuming that only some of the options for gross alpha or combined radium are
implemented, and then discuss the analysis under the assumption that all of the options are
implemented.
Independent implementation: EPA could choose to close only one of the monitoring
loopholes (e.g., to close the gross alpha loophole but not the combined radium loophole) or to
implement only one of the revised MCLs (e.g., to limit gross alpha to 10 pCi/L but leave the
combined radium MCL unchanged). The effects of incidental treatment will depend on the option
selected. For example, if the gross alpha loophole is closed, but the combined radium regulations
remain the same, only those systems that take action (i.e., install treatment, increase blending, or
change water sources) to comply with the revised gross alpha requirements will reduce their
concentrations of combined radium. We assume that the co-occurring radionuclides (e.g., combined
8 Treatment to remove the radionuclides assessed in this report will also reduce the levels of
other contaminants in the water; we do not quantify these other impacts in this preliminary analysis.
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radium) will be reduced by a percentage equal to the removal rate for the radionuclides directly
addressed by the regulatory option (e.g., gross alpha).
To avoid double-counting the risk reduction resulting from the incidental treatment of
radium-226, which is currently included in the definition of both combined radium and gross alpha,
our approach varies depending on the regulatory scenario. The risk factors and occurrence data used
to assess the direct impacts of closing the gross alpha loophole include radium-226, so we add only
the incidental decrease in radium-228. The risk factors and occurrence data used to assess the
change in the gross alpha MCL do not include radium-226 (since the MCL is redefined to exclude
this radionuclide), and the incidental risk reductions include both radium-226 and radium-228. For
combined radium, we follow a similar approach. Both radium-226 and radium-228 are included in
the analysis of the direct impacts for closing the loophole, so we calculate the incidental effects of
treatment on gross alpha than subtract the radium-226 value to avoid double-counting. For the
radium MCL (which limits radium-228), radium-226 is included in the analysis of the effects of
incidental treatment on gross alpha.9
Joint implementation: EPA may decide to close both loopholes and/or implement both
proposed MCLs. Under this scenario, we conduct the analysis of incidental treatment in two steps,
first considering the additional risk reductions that may occur for systems that are out of compliance
with the regulatory options for both gross alpha and combined radium, and then considering the
additional risk reductions that may occur for systems that are out of compliance with only one of the
options. In both cases, we adjust the results to insure that the risk reduction attributed to removal
of radium-226 is only counted once (as noted above, radium-226 is included in the current regulatory
definition of both gross alpha and combined radium).
For systems out of compliance for both gross alpha and combined radium, consideration of
joint implementation requires adjustments for two factors: (1) avoiding double-counting of removal
of radium-226, and (2) taking into account differences in removal rates. Hence we net out any
double counting of radium-226, and, in cases where different removal rates are required to achieve
the gross alpha and combined radium standards, we apply the higher removal rate to both groups of
radionuclides. For example, considering the two groups of radionuclides separately may lead us to
use a removal rate of 50 percent for gross alpha and 80 percent for combined radium; whereas, if we
assess them jointly, we would apply an 80 percent removal rate in both cases. Thus, we first identify
systems with differing removal rates, then calculate the incremental effects of the additional removal.
9 The revised baseline used to assess the changes in the MCLs assumes that both loopholes
are first closed. If the MCLs are changed without first closing the monitoring loopholes, the risk
reductions will differ somewhat from the estimates presented in this preliminary analysis.
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For systems out of compliance for only one group of radionuclides (either gross alpha or
combined radium), consideration of joint treatment could have a more significant effect on the risk
results. For example, considering the two groups of radionuclides separately may lead us to use a
removal rate of 50 percent for gross alpha and assume no removal of combined radium; whereas, if
we assess them jointly, we would apply a 50 percent removal rate in both cases. In these cases, we
apply the removal rate used for the relevant standard to the occurrence level for the other group of
radionuclides. In other words, if a system would apply a 50 percent removal rate to achieve the
combined radium standard, we assume their gross alpha levels would decrease by the same
percentage (again avoiding double-counting of the risk reductions associated with removal of
radium-226). Note that the impact of this additional removal on the risk results is limited by the fact
that concentrations of the co-occurring group of radionuclides are relatively low (below the target
MCL).
Valuation
The final step in the analysis of risk reductions involves estimating the value of avoiding
these risks. Below, we provide background information on the economic concepts that provide the
foundation for benefits valuation, and describe the methods that are typically used by economists
to value risk reductions, such as wage-risk, cost of illness, and contingent valuation studies. Next,
we describe the use of these techniques to estimate the value of the risk reductions attributable to the
regulatory options for radionuclides in drinking water. We discuss the approach for valuing the
reductions in fatal risks, then the approach for valuing the reductions in nonfatal risks.
Methods for Benefits Valuation
This section provides a brief overview of the theory and methods used to value reductions
in human health risks. It describes the concept of "willingness to pay," outlines standard valuation
approaches such as wage-risk, cost of illness, and contingent valuation studies, and explains how
estimates from these studies can be used to develop benefit values for environmental regulations.
Additional information on these topics is available in the EPA and OGWDW guidance documents
on benefits assessment.10
The practice of benefits valuation is based on the discipline of welfare economics, in which
value is measured by the "satisfaction" or "utility" individuals derive from an environmental
IOU.S. Environmental Protection Agency, Guidelines for Preparing Economic Analysis
(Review Draft), June 1999; U.S. Environmental Protection Agency, Assessing the Benefits of
Drinking Water Regulations: A Guidance Manual, forthcoming.
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improvement. Individuals reveal these values through their willingness to pay for effects of these
improvements. Willingness to pay is the maximum amount of money an individual would
voluntarily exchange to obtain an improvement (e.g., a reduction in health risks), given his or her
available financial resources and desired spending on other goods and services.
Willingness to pay is not the same as price or cost. Price is determined by the interactions
of buyers and sellers in the marketplace, while cost is a function of the materials, processes, and
labor used to create the good or service. Some individuals' willingness to pay for a particular good
or service will exceed the market price, in which case they benefit from the ability to buy the good
or service at the (lower) market price. Other individuals' willingness to pay will be less than the
market price, in which case they will not buy the good or service.
Because willingness to pay for improved health is difficult to directly observe in the
marketplace, economists most commonly use three types of studies to estimate the value of reduced
fatal and nonfatal risks: wage-risk studies; cost of illness studies; and contingent valuation studies.
EPA regulatory analyses often transfer estimates from existing studies to value the benefits of
alternative policies, as discussed below.
Wage-risk studies are often used to value changes in fatal risks; i.e., premature mortality.
These studies examine the additional compensation workers demand for taking riskier jobs, typically
focusing on small changes in the risk of accidental workplace fatalities. Researchers use statistical
methods to separate the changes in compensation that are associated with changes in risks from the
changes in compensation that are associated with other job characteristics.
The wage-risk method has several advantages; for example, the data and methods it uses are
well-established, and it directly measures changes in the risk of premature mortality. This method
is widely used to value reductions in fatal risks, and the available studies have been subject to
extensive peer review. However, these studies generally address risks from work place accidents
that differ in significant ways from the cancer and other risks associated with environmental
regulations.
The differences in the types of risks addressed can result in various types of bias when
estimates are transferred from wage-risk studies to value environmental risks. Many of these biases
appear to counterbalance each other, although the degree to which they do so is difficult to quantify.
For example, death is often more immediate in the case of workplace accidents than in the case of
cancers, which may have long latency periods between exposure and onset as well as long periods
of illness prior to death. However, the value of this delay may be counterbalanced by people's dread
of lengthy illnesses. The characteristics of the population addressed by available wage-risk studies
may also differ from the characteristics of the populations affected by the regulations; for example,
most wage-risk studies use data on middle-aged laborers, while environmental regulations often
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affect all members of the population: Despite these limitations, wage-risk studies may currently
provide the most defensible available estimates of the value of mortality risk reductions.
Cost of illness studies are often used to value changes in nonfatal (morbidity7) risks, but are
not a measure of willingness to pay. These studies examine the actual direct (e.g., medical expenses)
and indirect (e.g., lost work or leisure time) costs incurred by affected individuals. In general, the
logic for using cost of illness studies to value benefits is as follows: if illness imposes the cost of
medical expenditures and foregone earnings, then a regulation leading to a reduction in illness yields
benefits equal at minimum to the costs saved.
The cost of illness method is well-developed, widely applied, and easily explained. It
addresses direct and indirect costs that are relatively easy to measure and has been used to provide
estimates for large numbers of illnesses. In most cases, however, cost of illness studies may
significantly underestimate individuals' willingness to pay for decreased health risks because they
do not address factors such as pain and suffering.11 In addition, environmental regulations generally
reduce future risks, while the cost of illness method considers effects that have already occurred
and hence does not address risk aversion. Nonetheless, because of their widespread availability and
ease of use, cost of illness estimates are often used to value the nonfatal effects of environmental
regulations.
Contingent valuation studies use surveys to elicit statements of willingness to pay and are
often applied to value both fatal and nonfatal health effects. For example, researchers might ask
individuals what they would be willing to pay for a specified reduction in the risk of developing
stomach cancer from long-term exposure to contaminants in drinking water. The researchers can
define the scenario to address factors that may influence total willingness to pay, such as the pain
and suffering associated with an illness, thereby providing a more complete estimate of willingness
to pay. Such surveys must be carefully designed and administered, however, if they are to provide
reliable and precise estimates, because the individuals surveyed are usually not required to make
actual payments and may have difficulty understanding the scenario presented. For example, survey
respondents may understate their willingness to pay if they believe that wealthier individuals (or the
government) will pay related costs. Contingent valuation surveys have been completed for a
relatively small subset of the health effects associated with environmental regulations.
Benefits transfers from the above types of studies are often used in EPA regulatory analyses.
Rather than conducting new primary research on the value of reducing risks to human health,
analysts often use data from existing wage-risk, cost of illness, contingent valuation, or other studies
11 Cost of illness estimates may also occasionally overstate willingness to pay, particularly
if the availability of insurance leads people to agree to treatments that they would not fully finance
themselves.
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to estimate these values. Because these studies usually do not address the specific effects of concern
(e.g., cancer risks from radionuclides in drinking water), EPA's approach requires the application
of "benefit transfer" techniques. Benefit transfer refers to the use of valuation information from one
or more existing studies to assess similar, but not identical, effects associated with a regulation or
policy. To conduct a benefit transfer, analysts first must evaluate the quality and applicability (e.g.,
the similarity of the health effects and populations experiencing the effects) of the available studies,
then apply the results of selected studies (with any necessary adjustments) to the policy of concern.
Fatal Risks
To estimate the monetary value of reduced fatal risks (i.e., risks of premature death from
cancer) predicted under different regulatory options, we apply the value of a statistical life (VSL)
approach. VSL does not refer to the value of an identifiable life, but instead to the value of small
reductions in mortality risks in a population. A "statistical" life is thus the sum of small individual
risk reductions across an entire exposed population.
For example, if 100,000 people would each experience a reduction of 1/100,000 in their risk
of premature death as the result of a regulation, the regulation can be said to "save" one statistical
life (i.e., 100,000 * 1/100,000). If each member of the population of 100,000 were willing to pay
$20 for the stated risk reduction, the corresponding value of a statistical life would be $2 million
(i.e., $20 * 100,000). VSL estimates are appropriate only for valuing small changes in risk; they are
not values for saving a particular individual's life.
EPA has identified 26 VSL studies (that use the wage-risk or contingent valuation method)
which have been peer reviewed and recommended for use in EPA policy analyses.12 The best
estimates from these studies range from $0.8 million to $16.9 million and approximate a Weibull
distribution with a mean of $5.9 million (in 1998 dollars). To value the changes in fatal risks
associated with the radionuclides regulation, we apply a mean estimate of $5.9 million and low and
high end estimates of $ 1.5 million and $11.5 million, reflecting the uncertainty in these estimates.
The low and high end estimates represent the tenth and ninetieth percentile of the distribution of
VSL estimates, respectively.
Use of these estimates to value the averted risks of premature death associated with the
regulatory options for radionuclides is an example the benefit transfer technique, since the subject
of most of the studies (i.e., job-related risks) differs from the fatal cancer risks averted by the
12 U.S. Environmental Protection Agency, The Benefits and Costs of the Clean Air Act, 1970
to 1990, October 1997, Appendix I; and U.S. Environmental Protection Agency, Guidelines for
Preparing Economic Analysis (Review Draft), June 1999, Chapter 7.
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regulatory options. Applying these studies results in several sources of potential bias; however.
quantitative adjustments to address these biases generally have not been developed or adequately
tested and may be counterbalancing.
Some of the key sources of bias include the characteristics of the averted risks (whether they
are voluntary or involuntary, ordinary or catastrophic, delayed or immediate, natural or man-made,
etc.); the demographic characteristics of the group affected (e.g., age, income); the lag between
exposure and diagnosis or incidence of the disease (latency) as well as between incidence and death;
the baseline health status (i.e., whether a person is currently in good health) of affected individuals;
and the presence of altruism (i.e., individual's willingness to pay to reduce risks incurred by others).
For example, accidental deaths may be more immediate than cancer-related deaths, which often
involve a latency period between exposure and diagnoses. Some argue that the values reported for
accidental deaths should be reduced (or discounted) to reflect this latency period when applied to
cancers. However, there are several other sources of bias that may counterbalance the effects of
latency. These factors include the value of avoiding the dread, pain and suffering associated with
a lengthy illness as well as several other factors. The net effect of these sources of biases is difficult
to determine, and these issues are currently being investigated in more detail by EPA.13
Because of the uncertainties in these estimates, we estimate the value of reductions in fatal
risks attributable to the radionuclides regulations using the following estimates, as discussed above:
Mean Estimate: Value of fatal risk reductions = Statistical lives saved * $5.9 million
per statistical life
Low End Estimate: Value of fatal risk reductions = Statistical lives saved * $1.5 million
per statistical life
High End Estimate: Value of fatal risk reductions = Statistical lives saved * $11.5 million
per statistical life
Nonfatal Risks
To estimate the monetary value of reduced nonfatal cancers under different regulatory
options, ideally we would be able to predict the types of cancers averted by the regulations.
However, exposure to radionuclides can result in a range of cancers. The type of cancer depends
largely on where the radionuclides localize in the body as a result of one's metabolism. While some
13 These issues are discussed in more detail in EPA's draft Guidelines for Preparing
Economic Analysis (1999).
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radionuclides are associated with specific cancer types (such as leukemia, or colon, stomach, thyroid.
bone, and liver cancer), many are not, and radiation risk models generally consider several cancer
sites including the esophagus, stomach, colon, liver, lung, bone, skin, breast, ovary, bladder, kidney.
thyroid, red marrow (leukemia), as well as residual impacts on all remaining cancer sites combined.
Given the difficulties inherent in predicting the types of cancers averted by the radionuclides
regulations, we review the cost of illness estimates available for a range of nonfatal cancers that may
be most likely to result from exposure to radionuclides via tap water ingestion.14 EPA has developed
cost of illness estimates (medical costs only) for selected cancers, as reported in Exhibit 3-7.15 Note
that these estimates are preliminary and are now undergoing review.
Exhibit 3-7
LIFETIME AVOIDED MEDICAL COSTS FOR SURVIVORS
(1998 dollars)
Type of
Cancer
Date Data
Collected
Number of Cases
Studied
Estimated
Survival Rate
Mean Value per Nonfatal
Case
Colorectal
cancer
1974-1981
19,673
Medicare patients
53 percent
(after 10 years)
$109,800
(for typical individual
diagnosed at age 70)
Stomach
cancer
1974-1981
3,228
Medicare patients
< 20 percent
(after 5 years)
$90,800
(for typical individual
diagnosed at age 70)
Bone cancer
N/A; theoretical approach
64 percent
(after 5 years, includes
bone and joint cancers)
$91,800-5113,200
Notes:
Exhibit reports present value (at the time of onset) of the lifetime costs of the illness (using a 7 percent discount rate).
Values were inflated to 1998 dollars based on the consumer price index for the costs of medical commodities and
services.
Source: U.S. Environmental Protection Agency, Cost of Illness Handbook (draft), September 1998.
14 U.S. Environmental Protection Agency, Cost of Illness Handbook (draft), prepared by Abt
Associates, September 30, 1998, Chapters II. 1, II.2, and II.9.
15 D^
Because liver cancer has a high mortality rate (approximately 97 percent after 2! years),
we do not consider it in the valuation of nonfatal risks; fatal risks are assessed using the VSL method
discussed earlier in this section. We also do not include the estimates for kidney cancer, because the
cost of illness analysis does not separate the costs for survivors from the costs for non-survivors.
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For colorectal and stomach cancers, these estimates of direct medical costs are derived from
a study conducted by Baker et al., which uses data from a sample of Medicare records for 1974 -
1981.l6 These data include the total charges for inpatient hospital stays, skilled nursing facility stays,
home health agency charges, physician services, and other outpatient and medical services. These
costs are inflated using the medical care components of the consumer price index. EPA combines
these data with estimates of survival rates and treatment time periods to determine the average costs
of initial treatment and maintenance care for patients who do not die of the disease. Information on
mean age at diagnosis and survival rates are generally derived from a database maintained by the
National Cancer Institute, that covers the years 1973 - 1993.
For bone cancer (which is not addressed by Baker et al.), EPA uses a theoretical approach
that combines average values for initial and maintenance care from the Baker study with estimates
of the time period over which maintenance care is needed. The range reported in the exhibit above
reflects two different assumptions regarding the duration of maintenance care; a 10 year duration vs.
a duration based on average life expectancy at the age of diagnosis.
The EPA study also provides estimates of time lost due to illness for colorectal and stomach
cancer. For individuals diagnosed at age 70, the average lifetime lost hours are 2,266 for colorectal
cancer and 2,942 for stomach cancer. These estimates are based on a study conducted by Hartunian
et al., which calculated lost work time for the first year post-diagnoses.17 EPA then adjusts these
estimates to reflect lifetime lost hours including lost leisure time.18 For the typical stomach and
colorectal cancer survivor, all of the lost hours are assumed to occur in the first year post-diagnoses.
Because the cancers most often linked to the radionuclides of concern are usually diagnosed
late in life, this lost time is most likely to be leisure time during retirement. Determining the
appropriate value for such lost time is difficult, and is hence not included in the valuation estimates.
Studies of other diseases suggest that cost of illness values may significantly understate total
willingness to pay; however, little information is available on individuals' willingness to pay to avoid
16 Baker, Mary S. et al., "Site Specific Treatment Costs for Cancer: An Analysis of the
Medicare Continuous History Sample File," Cancer Care and Cost. DRGs and Beyond. Richard M.
Scheffler and Neil C. Andrews, Editors, Ann Arbor, MI: Health Administration Press Perspectives,
1989.
17 Hartunian, N.S., C.N. Smart, and M.S. Thompson, The Incidence of Economic Costs of
Major Health Impairments. Lexington, MA: Lexington Books, 1981.
18 U.S. Environmental Protection Agency. Cost of Illness Handbook (draft), September
1998, Chapters II. 1, II.2, and II.9
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cancer risks. Exhibit 3-8 summarizes the studies that compare cost of illness estimates to estimates
of total willingness to pay. These studies estimate total willingness to pay based on contingent
valuation or averting behavior studies. They vary in terms of the types of expenditures addressed
in the cost of illness studies; some exclude lost earnings and some exclude costs borne by others
(e.g., through insurance).
Exhibit 3-8
COMPARISON OF COST OF ILLNESS AND WILLINGNESS TO PAY ESTIMATES
Health Effect
Several minor health effects
(cough, congestion, headache, etc.)
Angina episodes
Asthma
Unspecified effects of ozone
Childhood exposure to lead
Chronic bronchitis
Study
Berger etal., 1987
Chestnut et al., 1988, 1996
Rowe and Chestnut, 1985
Dickie and Gerking, 1991
Agee and Crocker, 1996
U.S. EPA, 1997
Reported Range
for Ratio of Willingness to Pay
to Cost of Illness Estimates'
3.1 -78.9
2.9 - 8.0
3.2-9.8
1.9-4.2
2.1 -20.0
3.4-6.3
'For example, the Berger study suggests that, for several minor health effects, willingness to pay to avoid these health
effects is anywhere from three to almost 80 times larger than the cost of illness estimates.
For more information on these studies as well as full citations, see: U.S. Environmental Protection Agency,
Handbook for Noncancer Health Effects Valuation (Draft). September 30, 1998.
The ratios reported in Exhibit 3-8 cover a broad range, suggesting that the relationship
between cost of illness and willingness to pay values varies greatly depending on the health effect
of concern and the study methodology. Therefore we do not apply these ratios when considering the
extent to which cost of illness estimates may understate the value of nonfatal cancer risks averted
by the radionuclides rule. However, as discussed in the limitations section of this chapter, these
ratios indicate that the use of cost of illness estimates may substantially understate the value of
related benefits.
For the preliminary analysis, we use the approximate mid-point and high and low estimates
from Exhibit 3-7 to estimate the avoided medical costs attributable to reducing nonfatal cancer risks,
as summarized below.
Mid-Point Estimate: Value of nonfatal risk reductions (medical costs only) = Statistical
cases averted * SO. JO million
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Low End Estimate; Value of nonfatal risk reductions (medical costs only) = Statistical
cases averted * SO. 09 million
High End Estimate; Value ofnonfatal risk reductions (medical costs only) = Statistical
cases averted * SO. 11 million
As noted earlier, these cost of illness estimates are likely to understate total willingness to
pay for avoiding these cancers. They exclude certain types of avoided costs (e.g., lost work or
leisure time). In addition, the cost of illness approach does not address other factors that influence
willingness to pay, such as risk aversion and the desire to avoid pain and suffering.
FINDINGS
In this section, we present the results of the risk reduction analysis. The initial sections
discuss the results for community water systems for gross alpha, combined radium, and uranium.
Next we summarize the results and discuss the monetary value of the changes in risk. The final
section summarizes the implications of the limitations in our analysis.
Community Water Systems; Gross Alpha and Combined Radium
Below, we present the results of the risk analysis for closing loopholes in the existing
monitoring requirements and changing the MCLs for gross alpha and combined radium.19 These risk
reductions are assessed for ground water systems only because we do not expect these radionuclides
to occur above levels of concern in surface water. Appendix C presents detailed results for each
system size category.
Closing the Monitoring Loopholes
Under the initial baseline for the analysis, some systems legally exceed the current MCLs
for combined radium and gross alpha, due to the loopholes in the existing monitoring requirements
(discussed in Chapter 1). The first step in the analysis of the regulatory options therefore includes
assessing the effects of closing the monitoring loopholes, so that all systems are required to comply
with the existing MCLs. Exhibit 3-9 presents the risk reductions attributable to closing each
19 This chapter does not address risk reductions associated with full compliance with the
existing regulations (i.e., with elimination of illegal noncompliance) since these reductions are not
attributable to the changes EPA is now considering.
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loophole independently and then to closing both loopholes at the same time, under the two
approaches for estimating occurrence described in Chapter 2.
Exhibit 3-9
ANNUAL CANCER RISKS AVOIDED: CLOSING THE MONITORING LOOPHOLES
(community water systems)
Regulatory
Option
Close gross
alpha loophole
onlj:(MCL = 15
pCi/L)
Close combined
radium loophole
only (MCL = 5
pCi/L)
Close both gross
alpha and
combined
radium
loopholes jointly
System Size
Class
(population
served)
25 - 500 persons
501-1 million
persons
Subtotal
25 - 500 persons
501-1 million
persons
Subtotal
25 - 500 persons
501-1 million
persons
Subtotal
Directly Proportional
Total
Statistical
Cases
Avoided
0.04 cases
none
0.04 cases
0.05 cases
0.25 cases
0.31 cases
0.06 cases
0.25 cases
0.32 cases
Fatal
Statistical
Cases
Avoided
0.03 cases
none
0.03 cases
0.04 cases
0.1 7 cases
0.21 cases
0.04 cases
0.1 7 cases
0.22 cases
Lognormal Distribution
Total
Statistical
Cases
Avoided
0.04 cases
0.3 1 cases
0.35 cases
0.06 cases
0.48 cases
0.54 cases
0.07 cases
0.79 cases
0.86 cases
Fatal
Statistical
Cases
Avoided
0.03 cases
0.1 9 cases
0.22 cases
0.04 cases
0.33 cases
0.37 cases
0.05 cases
0.53 cases
0.57 cases
Notes:
1 . The risk reductions for each regulatory option include estimates of the benefits of incidental treatment, i.e., of the
effects of treatment for gross alpha on combined radium levels and vice-versa.
2. The benefits of incidental treatment are calculated using the directly proportional approach.
3. Detail may not add to total due to rounding.
For all the regulatory scenarios, the risks attributable to closing the monitoring loopholes for
gross alpha and combined radium are significantly smaller under the directly proportional approach.
These differences result because the lognormal approach generally leads to higher estimates of the
number of systems out of compliance, as well as higher estimates of the amount of removal these
systems need to achieve to comply with the MCL. If only the gross alpha loophole is closed, the
total cancer risk reductions are over eight times larger under the lognormal approach than under the
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direct proportions approach; 0.35 cases avoided compared to 0.04 cases. If just the combined radium
loophole is closed, the risk reductions estimated under the lognormal approach are one and three-
quarter times those estimated under the directly proportional approach; 0.54 total cases avoided vs
0.31 cases. Under both occurrence methodologies, the greatest reduction in risk is attributable to
large systems treating for combined radium.
Implementing both regulatory options simultaneously leads to risk reductions that are slightly
smaller than the sum of the results for the individual options (0.32 to 0.86 cases for the combined
options), because many systems are affected by both sets of requirements. As discussed in Chapter
2, we estimate that between 210 and 250 systems are legally exceeding the gross alpha MCL, while
270 to 320 systems are legally exceeding the combined radium MCL. These totals include about
170 systems that are legally exceeding both MCLs. Hence if both loopholes are closed, a total of
about 310 to 400 systems would be affected.
Revising the MCLs
Once the monitoring loopholes are closed and all systems comply with the current MCLs,
the next step in the analysis considers the effects of changes to the MCLs. Exhibit 3-10 reports the
risk reductions attributable to these changes.
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Exhibit 3-10
ANNUAL CANCER RISKS AVOIDED:
CHANGING THE GROSS ALPHA AND COMBINED RADIUM MCLS
(statistical cases)
Regulatory Option
Implement gross
alpha MCL at 10
pCi/L, net of
radium-226, only
Implement
combined radium
MCL at 5 pCi/L,
with radium-228
limited at 3 pCi/L,
only
Implement both
gross alpha and
combined radium
MCLs jointly
System Size Class
(population served)
25 - 500 persons
501-1 million
persons
Subtotal
25 - 500 persons
501-1 million
persons
Subtotal
25 - 500 persons
501-1 million
persons
Subtotal
Directly Proportional
Total
Statistical
Cases
Avoided
0.03 cases
0.49 cases
0.53 cases
0.01 cases
0.4 8 cases
0.50 cases
0.04 cases
0.74 cases
0.78 cases
Fatal
Statistical
Cases
Avoided
0.02 cases
0.32 cases
0.35 cases
0.01 cases
0.33 cases
0.34 cases
0.02 cases
0.49 cases
0.52 cases
Lognormal Distribution
Total
Statistical
Cases
Avoided
0.04 cases
0.66 cases
0.70 cases
0.02 cases
0.61 cases
0.63 cases
0.05 cases
1 .04 cases
1.08 cases
Fatal
Statistical
Cases
Avoided
0.02 cases
0.43 cases
0.45 cases
0.01 cases
0.42 cases
0.43 cases
0.03 cases
0.69 cases
0.72 cases
Notes:
1. The risk reductions for each regulatory option include estimates of the benefits of incidental treatment, i.e., of the
effects of treatment for gross alpha on combined radium levels and vice-versa.
2. The benefits of incidental treatment are calculated using the directly proportional approach.
3. Detail may not add to total due to rounding.
The risks attributable to these changes in the MCLs range from 0.53 to 0.70 total cases
avoided for gross alpha, 0.50 to 0.63 total cases avoided for combined radium, and 0.78 to 1.08 total
cases avoided if both MCLs are revised at the same time. For all three scenarios, the lognormal
approach results in larger estimates of risk reductions than does the direct proportions approach.
As discussed in Chapter 2, we estimate that between about 500 to 610 systems would exceed
the revised gross alpha MCL, while about 210 systems would exceed the limit on radium-228. The
risk results are similar for these options despite the large difference in the number of systems
affected largely because we assume that gross alpha poses a lower level of risk (see Exhibit 3-5 and
preceding discussion). If both the revised gross alpha standard and the revised combined radium
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standard are implemented jointly, the number of systems affected ranges from 570 to 670 systems.
The associated risks are less than the sum of the risks associated with implementing each option
independently because about 150 systems are out of compliance with both revised MCLs.
Community Water Systems: Uranium
In the previous chapter, we estimate that setting an MCL for uranium will affect from 40 to
970 systems, depending on the MCL selected and the approach used to estimate occurrence. Most
affected systems would be ground water systems. As indicated in Exhibit 3-11, establishing an MCL
for uranium would lead to an annual reduction of less than 0.01 to 2.12 cancer cases, depending on
the MCL selected and the occurrence methodology employed. More than half of these cases would
be fatal. As noted earlier, we do not assess the effects of treatment to remove uranium on gross
alpha and combined radium levels, because these radionuclides rarely co-occur at levels of concern
and may require different treatments.
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Exhibit 3-11
ANNUAL STATISTICAL CANCER CASES AVOIDED: SETTING AN URANIUM MCL
(community water systems)
Regulatory
Option
Uranium MCL
= 20pCi/L(20
/Jg/L)
Uranium MCL
= 40 pCi/L (40
^g/L)
Uranium MCL
= 80 pCi/L (80
A
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Community Water Systems: Summary of Results and Value of Risk Reductions
In Exhibit 3-12 below, we summarize the results of the risk analysis for community water
systems, based on the data presented in Exhibits 3-9, 3-10, and 3-11 above. We also provide
information on the monetary value of these risk reductions, apply these estimates for fatal and non-
fatal risk reductions discussed earlier in this chapter.
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Exhibit 3-12 II
SUMMARY OF ANNUAL RISK REDUCTIONS ASSOCIATED WITH EACH OPTION |
(community water systems) 4
Regulatory Option
Directly Proportional
Total Cancer Cases
Avoided
(fatal cases)
Value of Avoided
Cases
(range)
Lognormal Distribution
Total Cancer Cases
Avoided
(fatal cases)
Value of Avoided
Cases
(range)
Compliance with existing MCLs after closing monitoring loopholes (combined radium = 5 pCi/L, gross alpha = 15 pCi/L):1
Eliminate gross alpha monitoring
loophole only
Eliminate combined radium
monitoring loophole only
Eliminate both loopholes2
0.04 cases total
(0.03 fatal)
0.3 1 cases total
(0.21 fatal)
0.32 cases total
(0.22 fatal)
S0.2 million
(S<0.1-$0.3
million)
$1.2 million
(S0.3 - $2.4 million)
$1.3 million
($0.3 - $2.5 million)
0.35 cases total
(0.22 fatal)
0.54 cases total
(0.37 fatal)
0.86 cases total
(0.57 fatal)
$1.3 million
($0.3 - $2.6 million)
$2.2 million
($0.6 - $4.3 million)
$3.4 million
($0.9 - $6.6 million)
Compliance with revised MCL options:3
Revise gross alpha MCL to 1 0
pCi/L net of radium-226 onlv
Limit radium-228 at 3 pCi/L within
combined radium MCL of 5 pCi/L
onlv
Revise both gross alpha and
radium MCLs:
0.53 cases total
(0.35 fatal)
0.50 cases total
(0.34 fatal)
0.78 cases total
(0.52 fatal)
$2.1 million
($0.5 - $4.0 million)
$2.0 million
($0.5 -$3.9 million)
$3.1 million
($0.8 - $6.0 million)
0.70 cases total
(0.45 fatal)
0.63 cases total
(0.43 fatal)
1 .08 cases total
(0.72 fatal)
$2.7 million
($0.7 -$5.2 million)
$2.6 million
($0.7 - $5.0 million^
$4.3 million HI
($1.1 -$8.3 million) ||
Compliance with new uranium MCL options:
Establish uranium MCL at 20
pCi/L (20 Mg/L)
Establish uranium MCL at 40
pCi/L (40 Mg/L)
Establish uranium MCL at 80
pCi/L (80 Mg/L)
0.15 cases total
(0.10 fatal)
0.04 cases total
(0.02 fatal)
0.01 cases total
(
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This exhibit indicates that closing the gross alpha monitoring loophole alone will reduce total
cancer incidence by 0.04 cases under the direct proportions approach and by 0.35 cases under the
lognormal approach, including both direct impacts and the effects of incidental treatment. The
central tendency estimate of the value of these cases ranges from $0.2 million to $1.3 million.
Eliminating only the combined radium loophole results in a risk reduction of 0.31 total cancer cases
under the direct proportions approach and 0.54 total cancer cases under the lognormal approach. The
best estimate of the value of these cases ranges from $1.2 million to $2.2 million.
Closing the gross alpha and combined radium monitoring loopholes simultaneously will
reduce total annual cancer incidence by 0.32 cases under the direct proportions approach, including
both direct impacts and the effects of incidental treatment. This risk reduction increases to 0.86
cases under the lognormal approach. These estimates take into account the overlap between the
systems out of compliance under each loophole. About two-thirds of these avoided cases are likely
to be fatal. The central tendency estimate of the value of these cases ranges from $1.3 million to
$3.4 million.
Setting the gross alpha MCL to 10 pCi/L net of radium-226 without simultaneously changing
the combined radium standard reduces total annual cancer incidence by 0.53 total cases under the
direct proportions approach, including both direct impacts and the effects of incidental treatment.
This risk reduction increases to 0.70 cases under the lognormal approach. The best estimate of the
value of these cases ranges from $2.1 million to $2.7 million. Changing the combined radium
standard to limit the contribution of radium-228 to 3 pCi/L without also changing the MCL for gross
alpha results in a reduction in total annual cancer incidence of 0.50 cases under the direct proportions
approach and 0.63 cases under the lognormal approach. The central tendency estimate of the value
of these cases ranges from $2.0 million to $2.6 million.
Changing the MCLs for both gross alpha and combined radium will reduce total cancer
incidence by 0.78 to 1.08 cases, once the overlap between systems out of compliance for both
options is taken into account. The central tendency estimate of the value of these cases ranges from
$3.1 million to $4.3 million.
The additional impacts of uranium options range less than 0.01 cases to 2.12 cases avoided,
depending on the regulatory option and approach for estimating occurrence. The incremental
benefits of these risk reductions are valued at less than $0.1 million to $8.2 million annually.
IMPLICATIONS OF LIMITATIONS IN THE ANALYSIS
In this section, we discuss the major limitations of our methodology and the degree to which
they may lead us to under- or overstate the actual risk reductions associated with each regulatory
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option and the value of averting these risks. First, we discuss the limitations in the estimates of the
risk coefficients. Then, we describe other sources of uncertainty. The limitations in the occurrence
estimates (discussed in Chapter 2) will also affect the risk analysis.
Risk Coefficients
The risk coefficient estimates (from FOR-13) are characterized by significant uncertainties.20
These uncertainties result largely from the models and data used to derive key inputs. The
researchers estimate that some of the coefficients may change by a factor of more than 10 if plausible
alternative models or model inputs are used to predict risks. The starting point for the risk
coefficients reported in FOR-13 is risk coefficients from epidemiologic studies, which are then
adjusted through a series of steps. Key issues in this process, described in the report, include the
following.
Risk Models. These models take cancer coefficients from epidemiologic
studies and combine them with vital statistics and cancer mortality data for
the U.S. population to produce coefficients which measure the lifetime risk
per unit absorbed dose at each age group. Uncertainty in both the underlying
epidemiological studies (e.g. in the exposure estimates) and the functional
form of the risk model (which combines risk data with population and cancer
mortality data) contribute to the overall uncertainty in the FOR-13 estimates.
A key concern is the appropriateness of extrapolating the risk coefficients
from the epidemiologic studies. For example, the epidemiologic studies used
in the analysis involved subjects who experienced high radiation doses over
a short time period. Data on the response of humans to low doses of
radiation is unavailable; thus responses to low dose exposures must be
extrapolated from observations made at high, acutely delivered doses.
Biokinetic models. Radionuclide specific biokinetic models are used to
predict the distribution of a unit of activity in the body over time following
ingestion. The biokinetic models are simplifications of flows between organs
in complex biological systems. The degree of realism incorporated into the
models depends on the amount and quality of available information regarding
the actual paths of movement and the parameter values for specific elements
20 Eckerman, Keith F., Richard W. Leggett, Christopher B. Nelson, Jerome S. Pushkin, and
Allan C.B. Richardson, Cancer Risk Coefficients for Environmental Exposure to Radionuclides,
Federal Guidance Report No. 13 (Draft), September 1999.
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in the system. The use of equally plausible alternative biokinetic models
results in a range of risk coefficients.
Dosimetric models. Together with the results of the biokinetic models,
radionuclide-specific dosimetric models predict internal exposure (in terms
of absorbed dose) from ingested radionulides as they decay. The dosimetric
models are dependent on available information describing the decay
properties of the radionuclides of interest, the parameters describing the
source and target organs or regions of the body chosen for consideration and
the estimated effects of radiation on those targets. The assumptions used to
construct the dosimetric models affect the uncertainty of the resulting risk
coefficients.
While the report does not bound the uncertainty for all radionuclides, uncertainty categories
are provided by the researchers for selected cases. The researchers estimate that the risk coefficients
for uranium-234 and radium-226 may vary by a factor of seven depending on the model inputs used
to estimate risk. These estimates reflect current information on the biological behavior of
radionuclides in the human body, conversion from internally or distributed radioactivity to absorbed
doses to tissues, and extrapolation from tissue dose to cancer risk. The uncertainty categories do not
reflect uncertainties associated with the use of a linear, no-threshold model for estimating radiogenic
cancer at low doses, absorbed dose as a measure of radiogenic cancer risk, or variations in the
distribution of population exposure parameters (e.g., water intake rates).
Other Sources of Uncertainty
In addition to the uncertainties in the risk coefficients and occurrence data, other limitations
include the following.
Factors with indeterminate effects: There are significant uncertainties in the ingestion rates
used in this analysis. Ingestion rates vary depending on age and other factors, and the average used
in this analysis may differ from the average for the particular population affected by these regulatory
options. The approach used to estimate the risks associated with gross alpha reflects uncertainties
regarding the actual prevalence of different alpha emitters with varying degrees of risk. In addition,
statistical cancer incidence is based on average populations for each of the water system categories.
If the particular systems experiencing reductions in radionuclide concentrations have larger (or
smaller) populations, or are addressing alpha emitters with differ risk levels, the risk reductions will
be understated (or overstated).
The approach used to estimate the value of a statistical life is based largely on workplace
fatalities, and may under- or overstate individuals' willingness to pay to avoid fatal cancer risks. The
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analysis also does not assess the impacts of the regulatory options on other programs; e.g., the use
of the uranium MCL as a target level for clean-up of ground or surface water at contaminated sites.
Factors that may lead us to understate benefits: The calculation of the risk factors only
includes the ingestion of water from both drinking and meal preparation. It does not include
exposure via showering and bathing, laundry and cleaning, or other potential pathways, because
these risks are expected to be relatively small compared to the risks from ingestion. The risks of
kidney damage from uranium are also not quantified. In addition, the analysis focuses on the risks
to a "typical" individual, and does not address impacts on persons who may be particularly sensitive
to the effects of radiation. The analysis also does not include the effects of treatment for the
radionuclides on other contaminants present; i.e., unregulated radionuclides or toxic (e.g., inorganic)
contaminants.
The cost of illness approach used to value nonfatal risks is likely to understate individuals'
willingness to pay to avoid these risks, since it does not address risk aversion or the value of
avoiding pain and suffering. The value of lost time is also not included in these estimates. Finally,
the risk reductions (if any) associated with systems serving populations greater than one million are
not quantified in this chapter.
In addition, this analysis does not address benefits other than risk reductions. For example,
we do not consider the extent to which compliance with the revised radionuclides regulations could
improve the aesthetic properties (taste, odor color) of drinking water or reduce the materials damages
(e.g., soiling) associated with use of the water.
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CHANGES IN COSTS CHAPTER FOUR
In this chapter, we estimate compliance costs for community water systems, including the
changes in monitoring, treatment, and other costs associated with each regulatory option. As
discussed at the end of this chapter, these costs may also have market impacts, affecting the supply
and demand for drinking water from public systems. Below, we discuss the approach to the analysis
and then present the findings and limitations.1
ANALYTIC APPROACH
The analytic approach for assessing changes in costs includes first estimating the costs of
alternative compliance actions and then predicting the likelihood that each action will be undertaken.
The first section of this chapter describes the components of the cost analysis: monitoring,
treatment, and other compliance costs. The second section discusses the model used to predict costs
for systems in each size class and to estimate national and per household costs. Note that we do not
quantify costs for systems serving populations greater than one million; the analysis reported in
Chapter 2 suggests that few (if any) of these systems may be significantly affected by the regulatory
options.
Types of Compliance Costs
The regulatory options under consideration will increase the costs of monitoring to determine
compliance with each MCL as well as require certain systems to take action to reduce the
concentrations of radionuclides in their water. These latter actions may include installing treatment,
changing the water source used, or blending water from contaminated and uncontaminated sources.
1 The analysis reported in this chapter was conducted by William Labiosa of the U.S.
Environmental Protection Agency, Office of Ground Water and Drinking Water.
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Monitoring Costs
The regulatory options under consideration will increase monitoring costs for most water
systems. These increased costs result from the changes in the sampling and analysis requirements
needed to close the existing loopholes for gross alpha and combined radium. In addition, systems
would need to monitor uranium concentrations if EPA establishes a new MCL.
This preliminary analysis considers the following changes in monitoring requirements
(alternative approaches are discussed in EPA's Notice of Data Availability):
To close the gross alpha loophole, systems would be required to analyze samples
within 48 hours to capture the presence of radium-224. The regulatory provisions
allowing systems to hold their samples for longer time periods would be eliminated.
To close the combined radium loophole, systems would be required to analyze both
radium-226 and radium-228 concentrations. The provisions currently allowing
systems to avoid these analyses if gross alpha or radium-226 concentrations are low
would be eliminated.
To implement a new MCL for uranium, systems would be required to assess uranium
levels.
In addition, EPA is considering whether to require sampling at the entry point to the distribution
system rather than within the system, as well as whether to change the number of samples and the
timing and types of analyses required.
For community water systems, these costs are incremental to the costs of the sampling and
analysis currently required under the existing regulations. In other words, current monitoring costs
for radionuclides are subtracted from the costs under each regulatory option to determine the net
effects of the changes to the regulations. -Under the revised regulations, systems with higher
radionuclide concentrations would be required to monitor more frequently than systems with lower
concentrations, hence monitoring costs would increase as influent concentrations rise.2
As indicated in Exhibit 4-1, changes in annual per-site monitoring costs range from net
savings of $17 to net costs of $512 on average. These costs are per site (i.e., for individual entry
points within a system); total costs per system will depend on the number of locations where
2 U.S. Environmental Protection Agency, Costs of Additional Requirements for Monitoring
of Gross Alpha, Combined Radiums and Uranium (1976 versus 1999), provided by Wynne Miller,
EPA/OGWDW, April 29, 1999.
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monitoring is required. The largest annual per-site cost increase results from the new monitoring
requirements for uranium.
Exhibit 4-1
UNIT COSTS: CHANGES IN MONITORING REQUIREMENTS
Regulatory Option
Cost Increase Per Year Per Site
Eliminate monitoring loopholes, no changes to MCLs
Gross alpha at 15 pCi/L
Combined radium at 5 pCi/L
$11 -S252
$26 - $360
Changes to MCLs
Radium-228 at 3 pCi/L
Gross alpha at 10 pCi/L, net of radium-226
Uranium at 20, 40, or 80 pCi/L (ground and surface water)
($17) -SO
$11 -S252
$37 -$512
Notes:
1 . Gross alpha estimates assume analysis is required within 48 hours to address radium-224.
2. Actual costs will vary within these ranges depending on influent concentrations.
3. Numbers in parentheses indicate savings in comparison to current requirements.
Source:
U.S. Environmental Protection Agency, Costs of Additional Requirements for Monitoring of Gross Alpha, Combined
Radium and Uranium (1976 versus 1999), provided by Wynne Miller, Office of Groundwater and Drinking Water,
April 29, 1999.
Treatment Costs
Systems that detect radionuclide concentrations in excess of the MCLs have a number of
treatment options for reducing these concentrations. As discussed in the background documents for
this Notice of Data Availability (NOD A), the following technologies can be used for the effective
removal of gross alpha, radium, and/or uranium from drinking water: activated alumina,
coagulation/filtration, greensand filtration, ion exchange, lime softening, reverse osmosis, and point-
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of-use devices.3 For small systems, some of these technologies are more appropriate and affordable
than others, as also discussed in the background documents.4
The cost of installing these treatment technologies will vary depending on the initial
(influent) level of contamination as well as the quantity of water treated. To determine the costs of
each of these treatments, EPA considers the capital costs for installing the treatment, the operations
and maintenance costs associated with operating the technology, and the residuals handling and
disposal costs. Capital costs consist of process, construction, and engineering costs, which in turn
incorporate the following cost elements:
Process costs include manufactured equipment, concrete, steel, electrical and
instrumentation, pipes and valves, and housing costs.
Construction costs include sitework and excavation, subsurface considerations,
standby power, land, contingencies, and interest during construction.
Engineering costs include general contractor overhead and profit, engineering fees,
and legal, fiscal, and administrative fees (including permitting).
Operations and maintenance costs include the annual costs for materials, chemicals, power, and
labor.
In addition, total treatment costs include the capital and operations and maintenance costs
associated with options for residuals handling and disposal. Operation of many of the treatment
technologies generates solid or liquid residuals that contain elevated radionuclides levels and must
be disposed in a manner that complies with relevant laws and regulations.5
To estimate capital and operations and maintenance costs, EPA developed a set of unit cost
curves which calculate costs as a function of design or average flow. These costs vary depending
3 International Consultants, Incorporated, Technologies and Costs for the Removal of
Radionuclides from Potable Water Supplies (Draft), prepared for the U.S. Environmental Protection
Agency, April 1999.
4 International Consultants, Incorporated, Small System Compliance Technology List for the
Radionuclides Rule (Final Draft Report), prepared for the U.S. Environmental Protection Agency,
April 1999.
5 U.S. Environmental Protection Agency, Large Water System Byproducts Treatment and
Disposal Costs, April 1993, and U.S. Environmental Protection Agency, Small Water System
Byproducts Treatment and Disposal Costs, April 1993.
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on influent and effluent concentrations, i.e., the removal rate needed. Capital costs are a function
of the facility's design flow, while operations and maintenance costs are a function of average flow.
EPA estimated mean design and average flow rates based on the average population served for
systems in each size class.6 These flow estimates are combined with the cost curve equations to
predict costs for systems in each size class requiring different removal rates.
In Exhibit 4-2, we provide the range of treatment production costs (in dollars per thousand
gallons treated) applied for each treatment option considered for gross alpha, combined radium, and
uranium at 30 and 80 percent removal efficiencies. We also provide information on the cost of
point-of-use (e.g., residential) removal technologies for small systems. The options in this chart
include those that are likely to used most frequently by water systems, given their costs and other
factors. For gross alpha and combined radium, we consider only ground water systems because we
expect radionuclide concentrations to be below levels of concern in surface water (see discussion
in Chapter 2). For uranium, we present production costs for both ground water and surface water
systems.
6 Data on flow rates and population served are from International Consultants, Incorporated,
Drinking Water Baseline Handbook: First Edition (Draft), prepared for the U.S. Environmental
Protection Agency, March 2, 1999.
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Exhibit 4-2
UNIT COSTS FOR TREATMENT
(central tendency estimates of production costs per thousand gallons treated)
CENTRALIZED
TREATMENT
30 Percent Removal Efficiency
Small Systems
(25 - 500
persons served)
Large Systems
(501 - 1 million
persons served)
80 Percent Removal Efficiency
Small Systems
(25 - 500
persons served)
Large Systems
(501 - 1 million
persons served)
Removal of Gross Alpha and Radium from Ground Water
Water Softening/Iron Removal
Greensand Filtration
$0.77 -$1.78
$0.96 - $2.91
$0.21 -$1.11
$0.43 - $0.60
$1.71 -$2.69
NA
$0.54 -$1.68
NA
Removal of Uranium from Ground Water
Water Softening/Iron Removal
$0.77 -$1.78
$0.21 -$1.11
$1.71 -$2.69
$0.54 -$1.68
Removal of Uranium from Surface Water
Water Softening/Iron Removal
Enhanced Coagulation/
Filtration
$0.63 -$1.47
$1.23 -$5.24
$0.24 - $0.84
$0.18 -$0.61
$1.37 -$2.22
$1.23 -$5.24
$0.66 -$1.29
$0.18 -$0.61
POINT-OF-USE TREATMENT DEVICES
(systems serving 25 - 500 persons)
Point-of-Use Reverse Osmosis
Point-of-Use Ion Exchange/
Activated Alumina
$2.26 - $2.63
$2.26 - $2.63
Notes:
1 . Water softening/iron removal includes treatment technologies such as ion exchange, oxidation/filtration, reverse
osmosis, and lime softening.
2. NA means "not applicable."
Source:
Estimates provided by William Labiosa, EPA/OGWDW, November 22 and 23, 1999.
As indicated in the exhibit, production costs range from $0.18 to $5.24 per 1,000 gallons
treated, depending on system size, treatment technology, and influent contamination levels. The
upper bounds in the exhibit indicate treatment production costs for the smaller systems within each
of the two system size categories, while the lower bounds reflect costs for larger systems, indicating
economies of scale. Production costs are also driven by the number of sites per system; systems with
one site will have lower production costs than those with multiple sites. Enhanced coagulation/
filtration for removal of uranium from surface water systems yields the highest production costs,
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while the lowest costs are generally attributable to water softening/iron removal treatments (e.g.. ion
exchange, oxidation/filtration, reverse osmosis, or lime softening). Production costs for point-of-use
devices are relatively high compared to costs of other treatment options for small systems (i.e.. those
serving 25-500 persons); however, these devices may be simpler for small systems to implement
than centralized treatment.
Costs of Alternative Compliance Actions
In some cases, a system may achieve compliance by changing the water source used or by
adjusting its current operations. For example, a system may purchase water from a neighboring
system (i.e., regionalization) or it may change its own water sources (e.g., closing certain wells or
switching from ground water to surface water). Alternatively, it may increase the blending of water
from uncontaminated sources or adjust the operations of its existing treatment systems. For this
preliminary analysis, EPA considers two primary options: connecting with a neighboring system
(including blending with uncontaminated water), or developing a new source.7
Under the first option, the costs include constructing new mains to transport water from the
neighboring system to the existing local distribution system. Because the costs of purchasing the
water from a neighboring system (which achieves the MCLs) are counterbalanced by the savings
from no longer purchasing water from the local source, these charges are not considered in this
analysis. For this preliminary analysis, EPA assumes that the costs of blending (combining water
from uncontaminated and contaminated sources) will be similar to the costs of connecting with a
neighboring system. The alternate source scenario involves developing a new well in an area with
radionuclide concentrations below the MCLs.
Although in some cases these options may cost as much as or more as treatment, in other
cases they can be much less expensive and are often chosen as compliance options. For this
preliminary analysis, we assume that these options, on average, cost half as much as the cheapest
treatment option (i.e., water softening/iron removal). EPA plans to explore the uncertainty in these
compliance actions and cost estimates in more detail in the near future.
7 The alternative source option and associated costs are discussed in: The Cadmus Group,
Regional Variation of the Cost of Drinking Water Wells for Public Water Supplies (Draft), prepared
for the U.S. Environmental Protection Agency, October 1999.
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Per System. Per Household, and National Cost Estimates
The estimates described above are used in EPA's cost model to determine the per system.
per household, and national costs of each of the regulatory options. This modeling includes five
steps: (1) determine the number of systems out of compliance by system size class and removal rate
needed; (2) estimate treatment or other compliance costs for each system out of compliance; (3)
estimate monitoring costs for each system; (4) calculate per household costs; and (5) determine total
national costs. In a sixth and final step, we then adjust the estimates from the modeling to eliminate
double-counting of systems out-of-compliance with more than one option. We discuss each of these
steps below.
The starting point for the modeling is the occurrence estimates described in Chapter 2, which
predict the number of systems likely to be out of compliance under each of the regulatory options.
The occurrence analysis both identifies the percentage of systems out of compliance by size class
(i.e., by population served using the EPA system size classes reported in Exhibit 2-1) and by removal
rate category. The removal rate categories considered are less than 30 percent, 30 to 50 percent, 50
to 80 percent, and a maximum removal of 95 percent. The proportion of systems in each of these
categories is determined by comparing initial concentration levels to the MCL to determine the
percent removal needed.
The second step, estimating treatment or other compliance costs, includes consideration of
the number of entry points, or sites, within each system where treatment may be needed. Because
each water system may include multiple sites, it may be necessary for a system to install more than
one treatment technology resulting in higher capital, operations and maintenance, and monitoring
costs. The cost model is therefore designed to estimate the number of sites per system and assign
both treatment and monitoring costs at the site level.
EPA assumes that most ground water systems serving populations less than 3,300 persons
will have only one treatment site, but that a few of these systems may have as many as nine sites.
The percentage of systems likely to have more than one site generally rises as system size increases;
larger ground water systems serving populations between 50,001 and one million persons may have
as many as 37 sites per system. In general, surface water systems have fewer treatment sites; most
of these systems are likely to have only one site, and the maximum estimated for larger systems is
six sites.8 For systems with multiple sites, radionuclide concentrations are likely vary from site to
site; i.e., each site within a system may treat at a different removal rate. For this preliminary
8 Sites per system estimates are based on data from International Consultants, Incorporated,
Drinking Water Baseline Handbook: First Edition (Draft), prepared for the U.S. Environmental
Protection Agency, March 2, 1999.
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analysis, the cost model does not reflect this intra-system variability. However, EPA plans to
explore this issue in more detail in the near future.
To estimate the costs of treatment or other compliance options (such as changing water
sources), EPA developed a series of decision trees that predict the compliance technologies likely
to be used by system size and removal rate for each group of radionuclides. In general, EPA
assumes that a system will install the least expensive alternative. If more than one alternative has
the same costs, EPA assumes that the alternatives are implemented in the same proportions. In
considering these costs, EPA takes into account the capital, operation and maintenance, and waste
disposal costs described earlier.
In Exhibit 4-3, we summarize the assumptions regarding the frequency with which each
treatment may be applied in ground water systems, which varies by system size and influent
concentration.9 More detailed information on these assumptions, as well as information on the
assumptions used for surface water systems, is provided in Appendix D.
9 Decision trees provided by William Labiosa, EPA/OGWDW, November 22 and 23, 1999.
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Exhibit 4-3
COMPLIANCE OPTIONS FOR REMOVAL OF GROSS ALPHA, RADIUM, AND URANIUM
Compliance Option
Water Softening/
Iron Removal
MnO2 (Greensand)
Adsorption/Filtration
Enhanced Coagulation/
Filtration
Point-of-Use Reverse
Osmosis
Point-of-Use Ion Exchange/
Activated Alumina
Regionalization/Blending/
Other
Alternative Source
System Size
(population served)
25 - 500 persons
501-1 million persons
25 - 500 persons
501-1 million persons
25 - 500 persons
501 - 1 million persons
25 - 500 persons
501-1 million persons
25 - 500 persons
501-1 million persons
25 - 500 persons
501-1 million persons
25 - 500 persons
501-1 million persons
Frequency of Use
(ground water systems only)
Gross Alpha and
Radium
46 - 56 percent
36 - 66 percent
0- 10 percent
0 - 20 percent
NA
NA
5 percent
0-5 percent
5 percent
0-5 percent
1 7 percent
1 7 percent
1 7 percent
1 7 percent
Uranium
56 percent
66 percent
NA
NA
0 percent
0 percent
5 percent
0 percent
5 percent
0 percent
1 7 percent
1 7 percent
1 7 percent
1 7 percent
Notes (See Appendix D for more detailed information):
1. NA indicates that compliance option is "not applicable."
2. Percentages indicate the fraction of systems likely to use each compliance approach.
3. Estimates vary within ranges depending on system size and influent concentrations.
4 Water softening/iron removal includes treatment technologies such as ion exchange, oxidation/filtration, reverse
osmosis, and lime softening.
Source:
Based on information provided by William Labiosa, EPA/OGWDW, November 22 and 23, 1999.
For removal of gross alpha, radium, and uranium, most ground water systems exceeding an
MCL are likely to use a water softening/iron removal technology, which may include ion exchange,
oxidation/filtration, reverse osmosis, or lime softening. A small portion of systems (0 - 20 percent)
will likely chose greensand filtration for removal of gross alpha and radium, while an even smaller
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portion of primarily small systems (0-5 percent) will implement point-of-use devices for
radionuclide removal. Approximately 35 percent of all systems will likely employ a compliance
option other than treatment (i.e., regionalization, blending, or alternative source).
For surface water systems requiring uranium removal, the treatment technology assumptions
are largely the same as those for ground water systems. The principal difference is that a smaller
portion of systems are expected to use water softening/iron removal technologies, and more systems,
particularly larger ones, will use enhanced coagulation/filtration. Appendix D presents the detailed
gross alpha, radium, and uranium decision trees for both ground and surface water systems.
Using the decision trees to determine the percentage of systems installing each type of
treatment given the removal rates needed, EPA estimates the capital and operations and maintenance
costs for each regulatory option. The cost estimates for each treatment technology are developed
on a per-site basis and then weighted by the percentage of sites that are likely to install the treatment
according to the decision trees.
For example, if systems in a particular size class account for a total of 14,000 treatment sites
and the occurrence data lead us to predict that 0.1 percent of the systems will require 80 percent
removal to comply with an MCL option, the model will estimate that 14 sites (14,000 * 0.001) will
need to install treatment. If the decision trees indicate that 45 percent of the sites in this size and
removal rate category will install water softening/iron removal, then the model assumes that
approximately 6.3 sites (14 * 0.45) will apply this treatment. The model then multiplies the annual
capital and operations and maintenance costs (derived from the cost curves for this size class,
removal efficiency, and treatment technology) by the number of sites to generate an annual cost
estimate.
The third step in the cost analysis involves calculating monitoring costs for each system. All
systems will incur these costs regardless of whether they are out of compliance with a particular
regulatory option. Because these costs vary depending on radionuclide concentrations, EPA
estimates the percent of systems with concentrations within each of the following intervals: (1) less
than the detection level; (2) between the detection level and one-half the MCL; (3) between one-half
the MCL and the MCL; and (4) above the MCL. The percent of systems (by size class) within each
interval is predicted by assuming that concentrations are distributed lognormally based on the NIRS
data discussed in Chapter 2.
In the fourth step, EPA then estimates the change in per household water costs attributable
to the costs of the compliance actions. This calculation assumes that all of these costs are passed
onto the consumer and that the cost increases do not lead to changes in the quantity of water
consumed. Monitoring costs are not included in this calculation because they are too small to have
a noticeable impact on per household costs. The per household costs are determined by multiplying
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the average annual compliance costs per thousand gallons for systems in each size class by the
average annual per household water consumption (83,000 gallons per year).
In the fifth step, EPA adds the treatment and other compliance costs to the monitoring costs
for all systems across system size classes to determine the total national costs of each regulator)'
option. The resulting cost estimates are reported in the following section.
Finally, we adjust the estimate for double-counting. While EPA has developed separate cost
estimates for each regulatory option, simply summing these costs will overstate the total costs of
implementing all of the options simultaneously. Some systems may use a single type of treatment
or other strategy to comply with more than one option. This concern is particularly important for
gross alpha and combined radium, because several systems are affected by the options for both of
these groups of radionuclides. Estimates of the overlap between systems affected by each regulatory
option are provided in Chapter 2. To determine the costs associated with joint implementation, we
multiply the occurrence estimates for each size category (from Chapter 2), eliminating double-
counting, by a weighted average of the per system compliance costs.
FINDINGS
In this section, we present the results of the cost analysis. The initial section discusses the
results for community water systems for gross alpha and combined radium; we then describe the
findings for uranium. Next we summarize the findings for community water systems. The final
section of this chapter summarizes the implications of the limitations in the analysis.
Community Water Systems: Gross Alpha and Combined Radium
We assess the costs of complying with the regulatory changes under consideration for gross
alpha and combined radium in two incremental steps: first, we consider the costs associated with
closing the existing monitoring loopholes; then, we assess the additional costs attributable to
changing the MCLs.
Closing the Monitoring Loopholes
Exhibit 4-4 presents the cost increases attributable to closing loopholes in the existing
monitoring requirements for gross alpha and combined radium.10 These costs include: (1) the
10 This chapter does not address cost increases associated with full compliance with the
existing regulations (i.e., with the elimination of illegal noncompliance) because these increases are
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increase in monitoring costs for all systems, and (2) the treatment or other costs associated with
achieving compliance with the existing MCL for those systems currently out of compliance. The
costs are assessed for ground water systems only because we do not expect these radionuclides to
occur above levels of concern in surface water. Appendix E presents detailed results for each system
size category.
Exhibit 4-4
ANNUAL COST INCREASES: CLOSING THE MONITORING LOOPHOLES
(community water systems)
Regulatory
Option
Eliminate gross
alpha loophole
only (MCL =15
pCi/L)
Eliminate
combined
radium loophole
only (MCL 5
pCi/L)
Eliminate both
loopholes
simultaneously
System Size Class
(population served)
25 - 500 persons
501-1 million persons
Total
25 - 500 persons
501-1 million persons
Total
25 - 500 persons
501 - 1 million persons
Total
Number of
Systems
Affected
Total National
Cost Increase
Directly Proportional
2 1 0 systems
none
210 systems
210 systems
60 systems
270 systems
250 systems
60 systems
310 systems
$2.0 million
$0.5 million
$2.5 million
$1.5 million
$20.1 million
$21.6 million
$2.1 million
$20.1 million
S22.2 million
Number of
Systems
Affected
Total National
Cost Increase
Lognormally Distributed
1 70 systems
80 systems
250 systems
240 systems
70 systems
320 systems
250 systems
1 50 systems
400 systems
$1.7 million
$32.8 million
$34.5 million
$1.8 million
$37.0 million
S38.8 million
$2.1 million
$69.8 million
S71.9 million
Notes:
1 . Detail may not add to total due to rounding.
2. Costs are based on full compliance with existing regulations, i.e., assume elimination of illegal noncompliance
prior to changing the monitoring requirements.
3. The costs of eliminating both loopholes simultaneously are estimated by multiplying the unduplicated count of
affected systems (from Chapter 2) by the weighted average costs per system affected.
Source:
Cost estimates provided by William Labiosa, EPA/OGWDW, November 22 and 23, 1999.
We estimate that less than one percent of all systems are in legal noncompliance status.
However, these estimates vary depending on the approach used to estimate occurrence, as discussed
not attributable to the regulatory changes EPA is now considering.
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previously in Chapter 2. For gross alpha, once the monitoring loophole is closed, the annual cost
of achieving compliance with the existing MCL will total $2.5 million under the direct proportions
approach, and $34.5 million under the lognormal approach. On average, costs range from
approximately $12,000 per system ($2.5 million divided by 210 systems) to almost $140,000 per
system ($34.5 million divided by 250 systems).
The large variance in costs reflects significant differences in the number of systems predicted
to be out of compliance in the larger size classes (zero versus approximately 80) under the alternative
approaches; larger systems tend to have more treatment sites and greater compliance costs. The
lognormal approach also generally leads to higher predicted baseline occurrence levels, requiring
more costly technologies to achieve the removal rates needed to reach the MCL.
For combined radium, the predicted annual compliance costs total $21.6 million under the
direct proportions approach, and $38.8 million under the lognormal approach, or an average of about
$80,000 to $122,000 per system. For both of the regulatory options, most of the cost increase is
borne by large systems.
Because many systems are legally out of compliance with both MCLs, the total costs of
jointly implementing changes to the gross alpha and combined radium monitoring requirements will
be less than the sum of the costs reported in Exhibit 4-4 (i.e., less than $24.1 million under the direct
proportions approach, and less than $73.3 million under the lognormal approach). Gross alpha and
combined radium can be removed effectively by the same treatment technologies (or by using an
alternative water source), so systems can implement a single compliance action to achieve both
MCLs. The analysis in Chapter 2 suggests that most (about 80 percent) of the systems legally out
of compliance with the gross alpha MCL are also out of compliance with the combined radium MCL
under the direct proportions approach. To estimate the costs of implementing both regulatory
requirements simultaneously, we multiply the number of systems affected in each size category
(based on occurrence data from Chapter 2) by the weighted average costs per system. We find that
the costs of implementing both options range from $22.2 million to $71.9 million depending on the
approach used to estimate occurrence.
Revising the MCLs
Once the monitoring loopholes are closed and all systems comply with the current MCLs,
the next step in the analysis considers the incremental effects of changes to the MCLs. Exhibit 4-5
reports the cost increases attributable to these changes.
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Exhibit 4-5
ANNUAL COST INCREASES:
CHANGING THE GROSS ALPHA AND COMBINED RADIUM MCLS
(community water systems)
Regulatory
Option
Implement gross
alpha MCL at 10
pCi/L, net of
radium-226, only
Limit radium-
228 at 3 pCi/L,
within combined
radium MCL of
5 pCi/L, only
Implement both
MCL changes
simultaneously
System Size Class
(population served)
25 - 500 persons
501-1 million persons
Total
25 - 500 persons
501-1 million persons
Total
25 - 500 persons
501-1 million persons
Total
Number of
Systems
Affected
Total National
Cost Increase
Directly Proportional
420 systems
1 80 systems
610 systems
80 systems
120 systems
210 systems
420 systems
250 systems
670 systems
$2.5 million
$60.2 million
S62.7 million
$0.5 million
$40.1 million
S40.7 million
$2.5 million
$80.0 million
$82.5 million
Number of
Systems
Affected
Total National
Cost Increase
Lognormally Distributed
330 systems
1 70 systems
500 systems
130 systems
90 systems
210 systems
370 systems
200 systems
570 systems
$2.1 million
$69.5 million
S71.6 million
$0.8 million
$37.1 million
$37.9 million
$2.4 million
$81.3 million
S83.7 million
Notes:
1 . Detail may not add to total due to rounding.
2. Costs assume elimination of both illegal and legal noncompliance prior to changing the MCLs.
3. The costs of changing both MCLs simultaneously are estimated by multiplying the unduplicated count of affected
systems (from Chapter 2) by the weighted average costs per system affected.
Source:
Cost estimates provided by William Labiosa, EPA/OGWDW, November 22 and 23, 1999.
As discussed in Chapter 2, the number of systems affected by the gross alpha MCL is slightly
lower under the lognormal approach than under the direct proportions approach for estimating
occurrence. The cost increase that results from requiring systems to achieve the revised gross alpha
MCL ranges from $62.7 million to $71.6 million, or an average of about $103,000 to $143,000 per
system. For the limit on radium-228, the difference between the lognormal and direct proportions
results is smaller. The cost increase ranges from $40.7 million to $37.9 million, or an average of
about $197,000 to $179,000 per system. A significant proportion of these costs are attributable to
large systems out of compliance with the gross alpha MCL.
Because many systems will need to take action to comply with both revised MCLs, the total
costs of compliance will be less than the sum of the costs reported in Exhibit 4-5 (i.e., less than
$103.4 million under the direct proportions approach, and less than $109.5 million under the
lognormal approach). The analysis in Chapter 2 suggests that most (about 70 percent) of the systems
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out of compliance with the revised combined radium MCL are also out of compliance with the
revised gross alpha MCL under the direct proportions approach. To estimate the costs of
implementing both regulatory requirements simultaneously, we multiply the unduplicated count of
the number of systems affected (based on the analysis in Chapter 2) by the weighted average per
system costs for each system size category. We find that changing both MCLs simultaneously may
lead to annual national costs of $82.5 million to $83.7 million.
Community Water Systems: Uranium
As indicated in Exhibit 4-6, establishing an MCL for uranium would lead to an annual cost
increase of approximately $5 million to $157 million nationally, depending on the MCL selected and
the approach used to estimate occurrence." Average costs per system under an MCL of 20 pCi/L
range from approximately $38,000 to $162,000; under an MCL of 80 pCi/L, average costs range
from $119,000 to $175,000 per system. Most of these costs would be incurred by large systems
relying on ground water. Costs attributable to regulatory options for which no systems are out of
compliance are due to new monitoring requirements.
1' We do not assess potential double-counting for systems that are required to comply with
a new MCL for uranium as well as the regulatory options for gross alpha and combined radium
because uranium rarely occurs at levels of concern in systems affected by the other regulatory
options (see Chapter 2) and may require different treatment for effective removal.
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Exhibit 4-6
ANNUAL NATIONAL COST INCREASES: SETTING AN URANIUM MCL
(community water systems)
Regulatory
Option
Uranium MCL
= 20 pCi/L
(20/vg/L)
Uranium MCL
= 40 pCi/L
(40/zg/L)
Uranium MCL
=80 pCi/L
(80A/g/L)
System Size
Class
(population
served)
25 - 500
persons
501 - 1 million
persons
Total
25 - 500
persons
501 - 1 million
persons
Total
25 - 500
persons
501 - 1 million
persons
Total
Ground Water
Systems
Surface Water
Systems
All Systems
Directly Proportional
$7.1 million
(760 systems)
$22.1 million
(60 systems)
$29.2 million
(820 systems)
$3.2 million
(300 systems)
$1.1 million
(none)
$4.4 million
(300 systems)
$1.5 million
(40 systems)
$1.1 million
(none)
$2.7 million
(40 systems)
$1.3 million
(<10 systems)
$1.1 million
(none)
$2.4 million
(
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Industrial Economics, Incorporated: January 2000 Draft
Community Water Systems: Summary of Results
In Exhibit 4-7 below, we summarize the results of the cost analysis for community water
systems, based on the data presented in the previous exhibits. These results suggest uncertainty
regarding the actual costs of some options because the direct proportions and lognormal approaches
often lead to very different occurrence estimates. As noted earlier, EPA plan to conduct further
research on occurrence to reduce the uncertainty in these estimates.
Exhibit 4-7
SUMMARY OF ANNUAL COST INCREASES ASSOCIATED WITH EACH OPTION
Regulatory Option
Total National Cost Increase
Directly Proportional
Lognormally Distributed
Compliance with existing MCLS after closing monitoring loopholes (combined radium = 5 pCi/L, gross
alpha = 15 pCi/L):1
Eliminate gross alpha loophole only
Eliminate combined radium loophole only
Eliminate both loopholes simultaneously2
$2.5 million
$2 1.6 million
$22.2 million
$34.5 million
$38.8 million
$7 1.9 million
Compliance with revised MCL options:3
Revise gross alpha MCL to 10 pCi/L, net of
radium-226 only
Limit radium-228 at 3 pCi/L within combined
radium MCL of 5 pCi/L only
Revise both MCLs simultaneously2
$62.7 million
$40.7 million
S82.5 million
$7 1.6 million
$37.9 million
$83. 7 million
Compliance with new MCL options:
Establish uranium at 20 pCi/L (20 Mg/L)
Establish uranium at 40 pCi/L (40 Mg/L)
Establish uranium at 80 pCi/L (80 /ug/L)
$31.6 million
$6.7 million
$5.0 million
$1-57.0 million
$68.0 million
$29.9 million
Notes:
1 . Closure of loopholes is based on a full compliance baseline (i.e., occurrence data are adjusted to eliminate illegal
noncompliance).
2. Eliminates double-counting of systems affected by both options.
3. MCL changes are based on a revised baseline that eliminates monitoring loopholes (i.e., occurrence data are
adjusted to eliminate both illegal and legal noncompliance).
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As indicated by the exhibit, the costs associated with closing the individual monitoring
loopholes range from $2.5 million to $38.8 million, depending on the loophole and the approach
used to estimate occurrence. Closing both loopholes leads to estimated costs ranging from $22.2
million to $71.9 million, once we eliminate double-counting of systems legally out of compliance
with both MCLs.
The costs associated with changing the existing MCLs range from $37.9 million to $71.6
million, depending on the MCL and the approach for estimating occurrence. Changing both the
gross alpha and combined radium MCLs simultaneously leads to estimated costs ranging from $82.7
million to $83.7 million, once we remove double-counting of systems out of compliance with both
MCLs. The range of estimates is narrower for the MCL changes than for closing the loopholes,
because the direct proportions and lognormal approaches lead to relatively similar estimates of the
number of systems out of compliance.
For uranium, annual national compliance costs range from $5.0 million to $157.0 million,
depending on the MCL and approach for estimating occurrence. The lognormal approach leads to
significantly higher estimates in this case.
Exhibits 4-8 and 4-9 indicate the contribution of capital costs, operation and maintenance
costs, and monitoring costs to the total costs summarized above. The first exhibit provides the
results under the direct proportions approach; the second provides the results under the lognormal
approach. These exhibits assume that each option is implemented independently; the estimates are
not adjusted for double-counting of systems out of compliance with more than one option.
As shown in the exhibits, the highest costs are generally attributable to annual operations and
maintenance expenses. The exhibits also provide the capital and operation and maintenance costs
on a per-household basis, indicating a cost increase from close to $0 to $225 per household annually.
Detailed results by system size category are presented in Appendix E.
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Exhibit 4-8
BREAKDOWN OF TREATMENT AND MONITORING COSTS: DIRECT PROPORTIONS APPROACH
(community water systems)
Regulatory Option
Gross alpha loophole (MCL = 1 5
pCi/L)
Combined radium loophole (MCL = 5
pCi/L)
Gross alpha MCL = 10 pCi/L, net of
radium-226
Radium-228 limited at 3 pCi/L, within
combined radium MCL of 5 pCi/L
Uranium MCL =
20 pCi/L (20 //g/L)
Uranium MCL =
40 pCi/L (40 A/g/L)
Uranium MCL =
80 pCi/L (80 ^g/L)
Ground Water
Surface Water
Ground Water
Surface Water
Ground Water
Surface Water
Total Capital
Costs
$4,719,403
$96,220,123
$ 282,442,846
$ 184,478,821
$ 117,508,834
$ 112,204
$6,836,583
...
$ 800,952
Total
Annualized
Capital Costs
$ 443,624
$ 9,044,692
$ 26,549,628
$ 17,341,009
$ 11,045,830
$ 10,547
$ 642,639
$ 75,290
...
Annual Operations
& Maintenance
Costs
$882,192
$ 12,376,331
$36,170,183
$23,316,669
$ 15,305,144
$21,950
$ 1,144,406
...
$ 149,470
...
Annual
Monitoring
Costs
$ 1,157,132
$ 166,333
...
$2,886,203
$ 2,333,064
$2,582,384
$ 2,309,238
$ 2,446,495
$2,308,316
Total Annual
Costs
$ 2,482,948
$21,587,356
$62,719,810
$ 40,657,678
$29,237,178
$2,365,561
$ 4,369,429
$2,309,238
$2,671,254
$2,308,316
Annual Capital and O&M
Costs per Household
$0-$ 126
$6-$ 126
$6-$ 121
$6-$ 128
$ 13-$ 135
$0-$ 123
$0-$ 121
$0-$0
$0-$ 113
$0-$0
Notes:
1. Detail may not add to total due to rounding; estimates are not adjusted for double-counting of systems out of compliance with more than one option..
Source:
Based on data provided by William Labiosa, EPA/OGWDW, November 22 and 23, 1999.
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Industrial Economics, Incorporated: January 2000 Draft
Exhibit 4-9
BREAKDOWN OF TREATMENT AND MONITORING COSTS: LOGNORMAL DISTRIBUTION APPROACH
(community water systems)
Regulatory Option
Eliminate gross alpha loophole (MCL =
l5pCi/L)
Eliminate combined radium loophole
(MCL = 5 pCi/L)
Gross alpha MCL = 10
radium-226
pCi/L, net of
Radium-228 limited to 3 pCi/L within
combined radium MCL of 5 pCi/L
Uranium MCL = 20
pCi/L (20/jg/L)
Uranium MCL = 40
pCi/L (40^g/L)
Uranium MCL = 80
pCi/L (80/jg/L)
Ground Water
Surface Water
Ground Water
Surface Water
Ground Water
Surface Water
Total Capital
Costs
$ 145,985,859
$ 166,152,722
$314,887,220
$ 165,581,412
$ 608,783,775
$ 16,249,589
$ 254,674,397
$5,851,895
$ 101,457,305
$ 1,951,483
Total
Annualized
Capital Costs
$ 13,722,671
$ 15,618,356
$ 29,599,399
$ 15,564,653
$ 57,225,675
$ 1,527,461
$ 23,939,393
$ 550,078
$ 9,536,987
$ 183,439
Annual
Operations &
Maintenance Costs
$ 19,607,649
$ 23,024,706
$ 42,026,495
$ 22,299,598
$87,711,493
$ 5,084,334
$36,634,017
$ 1,826,124
$ 14,736,962
$611,888
Annual
Monitoring Costs
$ 1,182,966
$ 166,333
...
$3,015,334
$ 2,463,608
$2,684,158
$2,367,156
$2,527,514
$2,328,288
Total Annual
Costs
$34,513,286
$ 38,809,396
$71,625,893
$37,864,251
$ 147,952,502
$ 9,075,403
$ 63,257,568
$4,743,358
$26,801,462
$3,123,615
Annual Capital
and O&M Costs
per Household
$7-$ 126
$9-$ 127
$7-$ 126
$7-$ 125
$ 23 - $ 225
$ II -$ 124
$22-$2l7
$ 11 -$ 123
$22- $211
$ 11 -$ 125
Notes:
1. Detail may not add to total due to rounding.
Source:
Based on data provided by William Labiosa, EPA/OGWDW November 22 and 23, 1999.
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IMPLICATIONS OF LIMITATIONS IN THE ANALYSIS
In this section, we discuss the major limitations of our methodology and the degree to which
they may lead us to under- or overstate the actual cost increases associated with each regulatory
option. First, we discuss the uncertainties associated with predictions of compliance actions. Next.
we discuss potential market impacts. Finally, we describe other limitations of the analysis in
qualitative terms. The limitations in the occurrence estimates (discussed in Chapter 2) will also
affect the cost analysis.
Compliance Actions
EPA recently reviewed the actions that water systems have taken to come into compliance
with the MCLs for combined radium, nitrate and nitrite, and atrazine. These comprehensive analyses
indicate that most water systems choose compliance options other than treatment. The most
common of these options include modifications and/or additions to the present treatment system,
blending with less contaminated water (i.e., water below the MCL), adding new wells for blending
or replacement of contaminated wells, purchasing water from other water systems, and discontinuing
the use of contaminated wells when they are not necessary to meet water demand. Exhibit 4-10
presents the frequency of these alternative compliance actions, based on a preliminary analysis of
the analytic results.
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Exhibit 4-10
ACTUAL COMPLIANCE ACTIONS
Contaminant
Nitrate/
nitrite/
atrazine
Radium
Number
of
Systems
208
76
Compliance Action and Frequency of Use
(percent of systems)
Installed
Treatment
23.9
percent
27.6
percent
Modified
Existing
Operations
18.2 percent
none
Blended
13.6
percent
3.9
percent
Added
Well(s)
27.8
percent
10.5
percent
Purchased
Water
13.6
percent
51.3
percent
Discontinued
Contaminated
Well Use
2.8 percent
6.6 percent
Note:
In the case of radium, these actions were not necessarily taken for the purpose of complying with the MCL; however,
they brought the system into compliance.
Sources:
Data provided by William Labiosa, EPA/OGWDW, December 3, 1999.
1. Results for the States of OH, SD, FL, MO, CT, CA, WI, MN, NY, MD, OR, PA, and IN are from an unpublished
survey conducted by the Association of State Drinking Water Administrators, September 1999.
2. Radium results are for the State of Illinois, submitted by U. S. Environmental Protection Agency, Region 5.
These results suggest that the decision trees (provided in Appendix D) may overstate the
extent to which systems will choose to install treatment to comply with the regulatory options for
radionuclides. To address this limitation, EPA plans to further assess the effects that compliance
decisions may have on national costs, using Monte Carlo analysis to estimate the effects of
weighting options other than treatment more heavily in the decision trees. This analysis will be
based on probability distributions that reflect the likelihood that a system will choose a compliance
option other than treatment, and the likely costs of these alternative compliance options.
Based on preliminary investigation of this issue, we expect that the average costs of
compliance options other than treatment will be considerably lower than average treatment costs,
and hence may reduce the total national costs of compliance considerably.12 Therefore, EPA's
current emphasis on the use of treatment for compliance in national costing models is likely to result
in overestimates of national costs.
12 Abt Associates, Incorporated, "Case Study Memorandum, Assessing the Cost of
Compliance: A Drinking Water Retrospective (draft)," prepared for the U.S. Environmental
Protection Agency, November 17, 1998; and International Consultants, Incorporated, Actual Cost
for Compliance with the Safe Drinking Water Act Standard for Radium 226 and 228 - Final Report,
prepared for the U.S. Environmental Protection Agency, July 1998.
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Market Impacts
The analysis in the previous sections does not address the market effects of changes to the
regulations for radionuclides. Economic theory suggests that analysis of the impacts of regulations
on social welfare should take these types of effects into account. However, we expect that the costs
of implementing the regulations will have a relatively small impact on the supply and demand for
public water supplies, and hence do not quantify these effects. Examples of market impacts include
changes in water price (if the system passes the costs fully or partially on to its customers) and
changes in water consumption as a result of these price changes (e.g., reduced lawn watering in
response to price increases).13 Such impacts may mean that systems will reduce the amount of water
they produce, and consumers may decrease the amount of water they consume, if the regulations lead
to significant increases in costs.
Other Sources Of Uncertainty
In addition to the uncertainties in the occurrence estimates and in predicting compliance
actions discussed previously, several other factors affect the estimates of compliance costs. In
combination, these limitations lead us to believe that the analysis is likely to overstate the costs of
complying with the regulatory options under consideration for community water systems.
Factors with indeterminate effects: The analysis does not assess the impacts of the
regulatory options on other programs, e.g., the use of the uranium MCL as a target level for clean-up
of ground or surface water at contaminated sites.
Factors that may lead us to overstate cost increases: There are a number of uncertainties
in the unit cost estimates and in the decision trees used in this analysis that are discussed in the
background documents. While some of these uncertainties may be counterbalancing, EPA believes
that addressing these uncertainties (particularly in the capital cost estimates) is likely to decrease the
national costs reported above. Furthermore, recent research suggests that cost estimates generated
in these types of studies tend to overstate actual compliance costs, because they do not account for
13 Economists generally refer the relationship between price and quantity demanded as
"elasticity." Available studies suggest that elasticities for annual average residential water demand
in the United States generally range from -0.3 to -0.7 with only a few exceptions. A 1984 U.S. Army
Corps of Engineers review of 50 such studies concluded that it was most likely that average
elasticities were at the low end of the range, i.e., between -0.2 and -0.4. In other words, water
demand would decrease by 0.2 to 0.4 percent if prices increase by one percent. See: U.S. Army
Corps of Engineers, Influence of Price and Rate Structures on Municipal and Industrial Water Use,
June 1984.
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cost savings resulting from future technological innovation, cost reductions achieved during the
regulatory review and public comment periods, and other factors.14
Factors that may lead us to understate cost increases: This analysis does not include the
costs associated with changes to the requirements for systems serving populations greater than one
million; research conducted to-date suggests that few (if any) of these systems are likely to be
affected by the regulatory options under consideration. It also does not address the effects of the
regulatory options on Federal, state or local costs for program administration and enforcement.
14 Winston Harrington, Richard D. Morgenstern, and Peter Nelson, On the Accuracy of
Regulatory Cost Estimates, Resources for the Future, January 1999.
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NON-TRANSIENT NON-COMMUNITY WATER SYSTEMS CHAPTER FIVE
The prior chapters discuss the impact of the regulatory options on community water systems,
which are subject to the existing MCLs for radionuclides. EPA is also considering whether to extend
the regulations to cover non-transient non-community systems which are not currently subject to
these requirements. In this chapter, we provide information on the prevalence and concentrations
of radionuclides in water supplied by non-transient non-community water systems. The information
presented in this chapter is relatively general, and we are now conducting further research on this
topic to better estimate regulatory impacts. Below, we describe our approach to the analysis, present
our findings, and discuss the implications and limitations of the analysis.
The existing regulations (at 40 CFR 141.2) define a community water system as "a public
water system which serves at least 15 service connections used by year-round residents or regularly
serves at least 25 year-round residents." A non-transient, non-community water system is defined
as "a public water system that is not a community water system and that regularly serves at least 25
of the same persons over 6 months per year." The majority of non-transient non-community water
systems serve churches or schools. The remaining non-transient non-community water systems
serve a variety of facilities ranging from manufacturing to prisons to airports.1
ANALYTIC APPROACH
No source of national data currently exists that describes radionuclide occurrence in water
provided by non-transient non-community systems.2 Therefore, to provide insights into the potential
impacts of the regulatory options on these systems (which are not currently subject to the
radionuclides regulations), we review available data on the extent to which these systems are located
1 Science Applications International Corporation, Geometries and Characteristics of Public
Water Systems, prepared for the U.S. Environmental Protection Agency, May 14, 1999.
2 The NIRS sample used to estimate occurrence for the community water systems does not
include non-transient non-community water systems.
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in areas where radionuclide occurrence may exceed the regulatory standards being considered by
EPA. These data address raw, not finished, water and are regional ranges rather than values for
individual systems; hence, they are not sufficient to allow us to estimate the costs and risk reductions
associated with the regulatory options for these systems. We are currently examining other data
sources and developing estimates of the potential range of risk reductions and costs for these
systems, and will provide the resulting analysis as an Addendum to this report.
Data Sources
To determine the extent to which non-transient non-community water systems are located
in areas with potentially elevated radionuclide concentrations, we searched the literature for relevant
data. We found that available data sources provide information on radionuclide occurrence in raw
(unfinished) water in various geographic regions, rather than on occurrence in drinking water
supplied by these systems.3 These data do not provide estimates of the extent to which individual
systems are likely to exceed the radionuclide MCLs, because concentrations will vary within the
regions addressed and some non-transient non-community systems may treat their water before use
to comply with other regulatory requirements.4
We identified three hydrologic studies of ground water and surface water throughout the
United States that indicate the prevalence of radionuclides on a state-by-state base.5 The first study
was completed in 1987 by Research Planning Institute (RPI). The researchers collected data from
a variety of different sources, including scientific publications, municipalities, and state agencies,
then used this information in combination with information regarding the geology of regional ground
water aquifers to quantitatively extrapolate radium-226 concentrations for every county in the United
3 We focus on untreated water because non-transient non-community systems are subject to
only a subset of the existing MCLs and are not currently required to comply with the MCLs for
radionuclides. Most data on finished water supplies are for community water systems, which are
subject to substantially more regulatory requirements.
4 The extent to which these systems treat their water to address state or local water quality
requirements or concerns in the absence of Federal requirements is uncertain. Non-transient non-
community systems are subject to selected Federal MCLs, including those for certain organic and
inorganic chemicals. In some cases, treatment installed to comply with these MCLs may also reduce
radionuclide occurrence levels.
5 Data on the number of non-transient non-community systems in each state as of December
1997 (from SDWIS) are provided in Appendix A.
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States.6 The RPI study assigns each county to one of four categories based on the range of radium-
226 concentrations likely to occur in ground water in that county: less than 1 pCi/L, 1 to 5 pCi/L,
5 to 10 pCi/L, and greater than 10 pCi/L. We use these data to characterize the occurrence of
radium-226 in each state.
A second report by RPI, completed in 1984, uses previous studies of three major
hydrogeological provinces to identify types of aquifers that tend to have low or elevated activities
of radium-228.7 The report qualitatively classifies the radium-228 activity in each county across the
United States as low, medium, or high, depending on the type of bedrock and the location of aquifers
in that area. While the RPI study uses three categories for this classification, activity levels are
reported only for the "elevated" and "low" categories. The report notes that relatively low activity
levels include mean radium-228 concentrations ranging from 0.3 pCi/L to 0.7 pCi/L; elevated
activity levels include mean values from 1.4 pCi/L to 2.4 pCi/L, but may range as high as 23 pCi/L.
We assume that aquifers classified as "medium" have mean concentrations of 0.8 pCi/L to 1.3 pCi/L;
however, because this range is not explicitly noted in the report, it is possible that there is some
overlap between the ranges RPI actually used for each category. The RPI report then estimates the
occurrence of radium-228 in each county, based on regional geology. We use these data to estimate
the range of radium-228 activity levels found in each state.8
The third data source we use is a study of uranium completed by Oak Ridge National
Laboratory (ORNL) in 1981.9 The ORNL study provides concentration ranges for uranium that are
based extensively on National Uranium Resource Evaluation (NURE) data collected in the late
1970s. These ranges are based on actual water samples rather than estimated from hydrogeologic
6 Research Planning Institute, Creation of Generalized Maps of National Occurrence of
Uranium, Radium-226, and Radon in Groundwater based on Geological Considerations, February
1987(a).
7 Research Planning Institute, Aquifer Classification by Relative Risk ofRa-228 Occurrence,
September 1984. A later publication of the analysis included concentration ranges for eight states
not included in the 1984 version. See: Michel, J. and M.J. Jordana, "Nationwide Distribution of
Radium-228, Radium-226, Radon-222 and Uranium in Ground Water," Radon, Radium, and Other
Radioactivity in Ground Water: Hydrogeologic Impact and Application to Indoor Airborne
Contamination, (B. Graves, ed.), Lewis Publishers: Chelsea, Michigan, 1987(b), pp. 227 - 240.
8 The 1984 RPI report also presents information on uranium in a similar format. Because the
Oak Ridge study described below provides more detailed uranium data, we use the latter study in
our analysis.
9 Oak Ridge National Laboratory, Uranium in U.S. Surface, Ground, and Domestic Waters,
Volume 1, prepared for the U.S. Environmental Protection Agency, April 1981.
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Mail code 3201
1200 Pennsyivania Avenue NW
Washington DC 20460
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data. In states where NURE data were not available, ORNL relied on raw water samples of surface
and ground water collected by municipal and state agencies. These data are often much older than
the NURE data; however the report states that, for places where both NURE and more recent data
are available, correlation between the older and newer samples is high.
Approach
We use the three reports described above to estimate the number of non-transient non-
community systems that are located in states with levels of radionuclide occurrence that may exceed
the regulatory levels being considered by EPA. Data on the number of non-transient non-community
systems in each state as of 1997 is taken from SDWIS and is summarized in Appendix A. To
determine whether non-transient non-community systems are located in states where concentrations
may exceed either the existing MCLs or the MCL options considered in this report, we applied the
following decision rules.
Gross Alpha: None of the data sources reviewed provide estimates of gross alpha levels in
raw water sources. We therefore estimate these levels by reviewing the available data on radium-226
and radium-228. We consider only non-transient non-community systems that rely on ground water
sources because (as discussed in Chapter 2) we expect that gross alpha rarely occurs at levels of
concern in surface water.
To determine the extent to which such systems are located in states that may be affected by
application of the current MCL (15 pCi/L), we assume that total gross alpha is approximately equal
to the radium-226 value plus radium-228 multiplied by three. The "radium-228 value times three"
is used to estimate the concentration of radium-224 and its daughter products, based on recent
research (discussed in Chapter 2) on co-occurrence of these radionuclides.. This approach assumes
that the existing loophole in the monitoring requirements (which allows community water systems
to avoid measuring radium-224 levels) will be eliminated before applying the MCL to non-transient
non-community systems. When assessing a gross alpha MCL of 10 pCi/L (net of radium-226), we
rely solely on the estimates of radium-224 extrapolated from the available data on radium-228.
To determine whether systems are located in states with radionuclide occurrence potentially
above the current gross alpha MCL of 15 pCi/L, we apply the following decision rules.
If the state has radium-226 levels equal to or less than 5 pCi/L (in RPI 1987) and
radium-228 levels classified as "low" or "medium" (mean value less than 1.4 pCi/L
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in RPI 1984), we assume that systems located in the state are not likely to exceed the
current MCL.10
If the state has radium-226 levels between 5 and 10 pCi/L (in RPI 1987) and radium-
228 levels are classified as "low" (mean value less than 0.8 pCi/L in RPI 1984), we
also assume that systems located in the state are not likely to exceed the current
MCL.
The remaining states may have occurrence levels potentially exceeding the MCL.
To determine whether systems are located in states with radionuclide occurrence potentially
above the proposed gross alpha MCL of 10 pCi/L, net of radium-226, we apply the following
decision rules.
If the state has radium-228 levels classified as "low" or "medium" (mean value less
than 1.4 pCi/L in RPI 1984), we assume that systems located in the state are not
likely to exceed the proposed MCL.
The remaining states may have occurrence levels potentially exceeding the MCL.
Combined radium: For combined radium, we assess the likelihood that systems are located
in states where occurrence may exceed the current MCL of 5 pCi/L. (EPA is also interested in
determining the likelihood that systems will exceed an option that maintains a combined radium
MCL of 5 pCi/L but limits the contribution of radium-228 to 3 pCi/L. However, the data are not
specific enough to allow us to differentiate between these two options.") We focus on systems that
rely on ground water sources because (as discussed in Chapter 2) radium rarely occurs at levels of
concern in surface water. Again, we assume that the monitoring loopholes are addressed prior to
implementation of the MCL for these systems, so that they must fully comply with the standards.
To determine whether systems are located in states with occurrence levels potentially above
the current combined radium MCL of 5 pCi/L, we apply the following decision rules.
10 We use values that total less then 15 pCi/L because the RPI (1984) values are means, not
maximums, and some systems in each category are likely to exceed these means.
1' Based on the available data, the decision rules used to determine the number of systems
out of compliance with a combined radium MCL of 5 pCi/L that limits the contribution of radium-
228 to 3 pCi/L would be identical to the decision rules for the current combined radium MCL.
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If the state has radium-226 levels less than 1 pCi/L (in RPI 1987) and radium-228
levels are classified as "low" or "medium" (mean value less than 1.4 pCi/L in RPI
1984), we assume that systems located in the state are not likely to exceed the current
MCL.
If the state has radium-226 levels less than 5 pCi/L (in RPI 1987) and radium-228
levels are classified as "low" (mean value less than 0.8 pCi/L in RPI 1984), we also
assume that systems located in the state are not likely to exceed the current MCL.
The remaining states may have occurrence levels potentially exceeding the MCL.
Uranium: The ORNL report includes ranges from samples taken in each state. To
determine whether systems in a state are likely to exceed the uranium MCL options, we compare the
high end of the reported concentration range to the MCL. We conduct this analysis separately for
surface and ground water systems, and assume a one-to-one mass to activity ratio. The MCL options
considered are 20 pCi/L (20 /^g/L), 40 pCi/L (40 /ug/L), and 80 pCi/L (80 /ug/L).
FINDINGS
To assess radionuclide occurrence in non-transient non-community systems, we reviewed
data on the extent to which these systems are located in areas where radionuclide levels may
potentially exceed the regulatory standards being considered by EPA. In Exhibit 5-1, we report the
number of non-transient non-community systems located in states with gross alpha or combined
radium levels that could potentially exceed the current or proposed MCLs. (As discussed earlier,
the data do not allow us to distinguish between the current combined radium MCL (5 pCi/L) and the
alternative of limiting radium-228 to 3 pCi/L within this total; therefore, the later option is not
included in the exhibit.) Note that most of the systems located in the listed states are likely to have
radionuclide concentrations below levels of concern, both because the decision rules we apply are
conservative (i.e., may include states where concentrations are largely below levels of concern) and
because of the location and characteristics of individual systems, as discussed below.
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Exhibit 5-1
NON-TRANSIENT NON-COMMUNITY SYSTEMS LOCATED IN STATES WITH POTENTIALLY
ELEVATED GROSS ALPHA AND COMBINED RADIUM LEVELS
(ground water systems only)
Regulatory
Option
Exceed gross
alpha MCL of
15 pCi/L
Exceed gross
alpha MCL of
10 pCi/L, net
ofRa-226
Exceed
combined
radium MCL
of5pCi/L
States with Areas Potentially Exceeding MCL1
Alabama Iowa New Mexico South Carolina
Arkansas Maryland New York South Dakota
California Michigan North Carolina Texas
Colorado Minnesota North Dakota Virginia
Georgia Missouri Oklahoma Wisconsin
Idaho Montana Pennsylvania Wyoming
Illinois
Alabama Iowa New Mexico South Carolina
Arkansas Maryland New York South Dakota
California Michigan North Carolina Texas
Colorado Minnesota North Dakota Virginia
Georgia Missouri Oklahoma Wisconsin
Idaho Montana Pennsylvania Wyoming
Illinois
Alabama Idaho Montana South Carolina
Arizona Illinois New Jersey South Dakota
Arkansas Iowa New Mexico Texas
California Kansas New York Utah
Colorado Maine North Carolina Virginia
Connecticut Maryland North Dakota Washington
Delaware Michigan Oklahoma Wisconsin
Florida Minnesota Pennsylvania Wyoming
Georgia Missouri
NTNC Systems in Listed States
(percent of total)2-3
Number of
Systems
11,157
(60%)
11,157
(60%)
14,752
(79%)
Population
Served
3.232.839
(62%)
3.232.839
(62%)
4,200,139
(81%)
Notes:
(1) Based on data from RPI (1987a). RPI (1987b), and RPI (1984).
(2) Based on state-by-state 1997 SDWIS data.
(3) Exhibit does not indicate the number of systems out-of-compliance. Most of these systems are likely to have radionuclide
concentrations below levels of concern.
Exhibit 5-2 provides similar data for systems located in states with potentially elevated levels
of uranium. Roughly half the ground water systems and slightly more than one-quarter of the
surface water systems are located in states that may have uranium levels in excess of the MCLs
under consideration. Again, however, our approach may overstate the number of states with
potentially affected systems, and concentration levels are likely to vary significantly within each
state. Therefore, the exhibit may substantially overstate the number of systems potentially affected
by each regulatory option.
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Exhibit 5-2
NON-TRANSIENT NON-COMMUNITY SYSTEMS (NTNCS) LOCATED IN STATES WITH POTENTIALLY ELEVATED URANIUM LEVELS
Regulatory Option
Exceed MCL of 20 pCi/L
(20 ng/L)
Exceed MCL of 40 pCi/L
(40/,g/L)
Exceed MCL of 80 pCi/L
(80A
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IMPLICATIONS AND LIMITATIONS OF THE ANALYSIS
In this section, we discuss the major limitations of our methodology. We are currently
researching the affects of the regulatory options on non-transient non-community systems in more
detail, and plan to report the results in an Addendum to this document.
Factors that may lead us to overstate occurrence: The data reported in this chapter are
not sufficient to estimate the number of non-transient non-community water systems that may be
affected by the regulatory options under consideration. Instead, they provide an upper bound
estimate of the number of states with potentially elevated levels.12 Radionuclide concentrations vary
significantly between locations within each state and many systems may rely on water sources that
do not exceed the MCLs. In addition, some systems may have installed treatments that reduce
radionuclide concentrations below levels of concern, either in response to regulations for other
contaminants or concerns about exposure to radiation. Therefore, the data presented in the exhibits
may substantially overstate the number of systems potentially affected by each regulatory option.
The available data suggest that most systems in the listed states may not exceed the MCLs.
For example:
Review of the NIRs data (in Chapter 2) indicates that the total number of community ground
water systems in illegal or legal noncompliance status with the gross alpha and/or combined
radium MCLs is less than three percent of all systems nationally.13 For uranium, the rate of
noncompliance is two percent or less of all (surface and ground water) systems nationally,
depending on the regulatory option assessed.14 While the absence of regulation of non-
transient non-community systems suggests that noncompliance rates may be higher than
12 There is also significant uncertainty associated with the studies which are the basis for
analysis in this chapter. Radionuclide concentrations are extrapolated based on limited geologic data
or water samples, and are not always expressed in quantitative terms.
13 Analysis conducted by EPA suggests that the number of systems located in each EPA
region is relatively similar for small (serving populations of 25 - 3,300) community ground water
systems and non-transient non-community systems. To the extent that areas of elevated radionuclide
concentrations correspond with regional boundaries, these data suggest that concentrations in water
sources used by community and non-transient non-community systems may be similar. (Personal
communication with William Labiosa, EPA/OGWDW, December 1999.)
14 Uranium is not regulated for either community or non-community systems; however,
community systems may have lower occurrence levels if treatments installed to remove other
contaminants remove uranium as well.
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those reported for community systems, these data suggest that the percentages in Exhibits
5-1 and 5-2 may substantially overstate the rate of noncompliance.15
Data provided by individual states indicates that only a fraction of the systems are likely to
be out of compliance due to the variance in radionuclide concentrations within state
boundaries. For example, in Illinois (which has relatively high radionuclide concentrations),
data presented in Chapter 2 suggests that less than ten percent of the community ground
water systems are not complying with the existing regulations. Illinois state staff roughly
estimate that perhaps 14 percent of the non-transient non-community systems in the state
may exceed the combined radium MCL of 5 pCi/L.16 For Wisconsin, state staff roughly
estimate that less than eight percent of the systems may exceed this MCL.17
These data suggest that perhaps between two or three percent and 15 percent of the systems located
in the states listed in the above exhibits may exceed the MCLs under consideration. We are now
conducting additional research to gain further insights into these issues.
15 Analysis conducted by EPA indicates that, for regulated inorganic contaminants which
have physical properties similar to radium, community water supplies have a greater probability of
reported violations than non-transient community water systems, suggesting that non-transient
systems could have lower occurrence levels than community systems. (Personal communication
with William Labiosa, EPA/OGWDW, December 1999.)
16 Information provided by Miguel Deltoral, EPA Region 5, to Amit Kapdia, EPA/OGWDW,
August 26, 1998.
17 Information provided by Judy Adams, Wisconsin Department of Natural Resources, to
William Labiosa, EPA/OGWDW, June 22, 1998.
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SUMMARY AND CONCLUSIONS CHAPTER SIX
This chapter summarizes the results of the preliminary assessment of the costs and benefits
of the regulatory options EPA is considering for radionuclides in drinking water. It discusses the
changes in risk which coincide with changes in the costs of complying with each option, and
compares the resulting costs and benefits.
The chapter contains two sections. The first section examines the potential incremental
effects of the regulatory options relative to baseline conditions, including closing the monitoring
loopholes and establishing new or revised MCLs. The second section discusses the implications and
key limitations of this analysis, including a description of the costs and benefits that have not been
quantified.
COMPARISON OF COSTS AND BENEFITS
This section compares the quantified cost increases associated with compliance with each
regulatory option to the resulting benefits for community water systems. These costs include the
monitoring, capital costs, and operations and maintenance costs described in Chapter Four. The
quantified benefits include the decreased incidence of fatal and nonfatal cancers, as described in
Chapter Three. Other impacts, such as the effects of the regulatory options on non-transient, non-
community water systems and systems serving populations greater than one million, the use of
MCLs as clean-up standards, and the effects of treatment on other contaminants present and resulting
risk reductions, are not quantified in this preliminary analysis.
As discussed in Chapter One, some community water systems may legally exceed the current
MCLs for gross alpha and combined radium, because the existing regulations include loopholes in
the monitoring requirements that allow systems to avoid analyzing for the presence of certain
radionuclides. EPA is now considering whether to close these monitoring loopholes, which would
result in the costs and benefits summarized in Exhibits 6-1, 6-2, and 6-3 on the following pages.
These impacts include the incremental costs of the new requirements for sampling and analysis. In
addition, once the monitoring requirements are changed, some systems will find that they are out of
compliance with the existing MCLs. Hence, for these systems, the impacts of the options for closing
the loopholes include the costs and risk reductions associated with achieving the existing MCLs.
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EPA is also considering whether to revise the MCLs for gross alpha and combined radium.
as well as whether to establish a new MCL for uranium (which is not currently regulated). The costs
and benefits of the alternative MCLs are also summarized in the exhibits. Exhibit 6-1 provides the
estimates of the number of systems out of compliance using the direct proportions and lognormal
approaches for estimating occurrence (as described in Chapter 2). Exhibits 6-2 and 6-3 provide the
cost and risk results using the direct proportions and lognormal distribution approaches. More
information on the risk and cost results is provided in Chapters Three and Four.
Exhibit 6-1
NUMBER OF COMMUNITY WATER SYSTEMS EXCEEDING STANDARDS
Option
Number of
Systems
Illegally out of compliance with existing MCLs (combined radium = 5 pCi/L, gross alpha = 15 pCi/L) '
Illegal noncompliance: gross alpha
Illegal noncompliance: combined radium
Total number of systems in illegal noncompliance (adjusts for overlap)
400 systems
420 systems
670 systems
Legally out of compliance with existing MCLs (due to monitoring loopholes)2
Legal noncompliance (due to monitoring loopholes): gross alpha
Legal noncompliance (due to monitoring loopholes): combined radium
Total number of systems in legal noncompliance (adjusts for overlap)
21 0-250 systems
270 - 320 systems
3 10 -400 systems
Out of compliance with options for revising MCLs 3
Gross alpha at 10 pCi/L net of radium 226
Combined radium at 5 pCi/L with radium-228 limit at 3 pCi/L
Total number of systems out of compliance with revised radium or gross alpha MCL
(adjusts for overlap)
5 00 -610 systems
210 systems
570 - 670 systems
Out of compliance with options for uranium MCL
Uranium at 20 pCi/L (20 Mg/L)
Uranium at 40 pCi/L (40 Mg/L)
Uranium at 80 pCi/L (80 Mg/L)
830 - 970 systems
300 - 430 systems
40 - 1 70 systems
Notes:
Ranges based on directly proportional versus lognormal distribution approach. Combined radium and gross alpha analyses
include ground water systems only; uranium analysis includes both ground water and surface water systems.
1 . Costs and risk reductions associated with complying with existing requirements for these systems are not assessed because these
impacts are not attributable to the changes in requirements now under consideration.
2. Compared to initial baseline (i.e., occurrence data are adjusted to eliminate illegal noncompliance).
3. Compared to revised baseline (i.e., occurrence data are adjusted to eliminate legal noncompliance with both gross alpha and
combined radium MCLs).
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As indicated by the exhibit, about 670 systems were illegally out of compliance when the
NIRS data were originally collected, if we adjust for double-counting. More recent data suggest that
illegal noncompliance may have decreased somewhat since that time. Once we adjust the data to
eliminate this illegal noncompliance, we find that between about 310 and 400 systems will be in
legal noncompliance status with one or both of the existing MCLs, depending on whether we use
the direct proportions or lognormal approach to estimate radionuclide concentrations. After the
monitoring loopholes are closed, a total of 570 to 670 systems may be out of compliance with one
or both of the MCL options for gross alpha and combined radium. In addition, the MCL options for
uranium may affect from about 40 to almost 1,000 systems, depending on the option selected and
the approach used to estimate noncompliance. In general, the estimates of the number of systems
out of compliance are higher under the lognormal approach than under the direct proportions
approach.
The costs and benefits associated with complying with the regulatory options are summarized
on the following pages. We first report the results for the direct proportions approach and then
report the results for the lognormal approach.
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Exhibit 6-2
SUMMARY OF QUANTIFIED ANNUAL COSTS AND BENEFITS:
DIRECT PROPORTIONS APPROACH
(community water systems)
Total Cancer Cases
Avoided
(fatal cases)
Value of Avoided Cases
(range)
Total Change in
Compliance Costs
Compliance with existing MCLs after closing monitoring loopholes (combined radium = 5 pCi/L, gross
alpha = 15 pCi/L)1
Eliminate gross alpha
monitoring loophole only
Eliminate combined radium
monitoring loophole only
Eliminate both loopholes2
0.04 cases total
(0.03 fatal)
0.31 cases total
(0.21 fatal)
0.32 cases total
(0.22 fatal)
$0.2 million
($<0.1 - $0.3 million)
$1.2 million
($0.3 - $2.4 million)
$1.3 million
($0.3 - $2.5 million
$2.5 million
$2 1.6 million
$22.2 million
Compliance with revised MCL options 3
Revise gross alpha MCL to 1 0
pCi/L net of radium-226 only
Limit radium-228 at 3 pCi/L
within combined radium MCL
ofSpCi/Lonly
Revise both gross alpha and
radium MCLs2
0.53 cases total
(0.35 fatal)
0.50 cases total
(0.34 fatal)
0.78 cases total
(0.52 fatal)
$2.1 million
($0.5 - $4.0 million)
$2.0 million
($0.5 -$3.9 million)
$3.1 million
($0.8 - $6.0 million)
$62.7 million
$40.7 million
$82.5 million
Compliance with new uranium MCL options
Establish uranium MCL at 20
pCi/L (20 //g/L)
Establish uranium MCL at 40
pCi/L (40 Mg/L)
Establish uranium MCL at 80
pCi/L (80 Mg/L)
0.15 cases total
(0.10 fatal)
0.04 cases total
(0.02 fatal)
0.01 cases total
(<0.01 fatal)
$0.6 million
($0.2 -$1.2 million)
$0.1 million
($<0.1 - $0.2 million)
$<0.1 million
$31.6 million
$6.7 million
$5.0 million
Notes:
See text for discussion of non-quantified impacts and limitations in the analysis.
Gross alpha and combined radium risk estimates include risk reductions due to incidental treatment; e.g., the removal of gross
alpha by treatments installed to address combined radium and vice-versa.
1 . Compared to full compliance baseline (i.e., occurrence data are adjusted to eliminate illegal noncompliance).
2. Removes double-counting of systems affected by both options.
3. Compared to revised baseline (i.e.. occurrence data are adjusted to eliminate legal noncompliance).
6-4
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Industrial Economics, Incorporated: January* 2000 Draft
Exhibit 6-3
SUMMARY OF QUANTIFIED ANNUAL COSTS AND BENEFITS:
LOGNORMAL DISTRIBUTION APPROACH
(community water systems)
Total Cancer Cases
Avoided
(fatal cases)
Value of Avoided
Cases
(range)
Total Change in
Compliance Costs
Compliance with existing MCLs after closing monitoring loopholes (combined radium = 5 pCi/L, gross
alpha = 15 pCi/L)1
Eliminate gross alpha monitoring
loophole only
Eliminate combined radium
monitoring loophole only
Eliminate both loopholes2
0.35 cases total
(0.22 fatal)
0.54 cases total
(0.37 fatal)
0.86 cases total
(0.57 fatal)
$1.3 million
(S0.3 - $2.6 million)
$2.2 million
($0.6 - $4.3 million)
$3.4 million
($0.9 - $6.6 million)
$34.5 million
$38.8 million
$7 1.9 million
Compliance with revised MCL options3
Revise gross alpha MCL to 10 pCi/L
net of radium-226 only
Limit radium-228 at 3 pCi/L within
combined radium MCL of 5 pCi/L
only
Revise both gross alpha and radium
MCLs2
0.70 cases total
(0.45 fatal)
0.63 cases total
(0.43 fatal)
1 .08 cases total
(0.72 fatal)
$2.7 million
($0.7 - $5.2 million)
$2.6 million
($0.7 - $5.0 million)
$4.3 million
($1.1 -$8.3 million)
$71.6 million
$37.9 million
$83.7 million
Compliance with new uranium MCL options
Establish uranium MCL at 20 pCi/L
(20 Mg/L)
Establish uranium MCL at 40 pCi/L
(40 Mg/L)
Establish uranium MCL at 80 pCi/L
(80 Mg/L)
2.12 cases total
(1.37 fatal)
1 .54 cases total
(l.OOfatal)
1 .03 cases total
(0.67 fatal)
$8.2 million
($2.1 -$15. 8 million)
$6.0 million
($1.5 -$11. 6 million)
$4.0 million
($1.0 -$7.7 million)
$157.0 million
$68.0 million
$29.9 million
Notes:
See text for discussion of non-quantified impacts and limitations in the analysis.
Gross alpha and combined radium risk estimates include risk reductions due to incidental treatment; e.g., the removal of gross
alpha by treatments installed to address combined radium and vice-versa.
1 . Compared to full compliance baseline (i.e., occurrence data are adjusted to eliminate illegal noncompliance).
2. Removes double-counting of systems affected by both options.
3. Compared to revised baseline (i.e., occurrence data are adjusted to eliminate legal noncompliance).
6-5
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Industrial Economics, Incorporated: January 2000 Draft
Under the direct proportions approach, Exhibit 6-2 indicates that risk reductions total less
than one statistical cancer case annually for each option, and that compliance costs range from $2.5
million to $82.5 million depending on the options considered. Under the lognormal approach,
Exhibit 6-3 indicates that risk reductions range from less than one to slightly more than two
statistical cancer cases annually, and that compliance costs range from $34.5 million to $157.0
million depending on the options selected.
These exhibits show that the alternative approaches for estimating occurrence lead to
substantially different estimates of risk reductions and compliance costs for some of the regulatory
options. However, under both approaches, costs exceed the value of the risk reductions by a
substantial amount.
As indicated by the exhibits, most of the regulatory options would change the statistical risks
of incurring fatal or nonfatal cancers by less than two cases per year; in general, fatal cases are
roughly two-thirds of the total cases avoided. The mean estimate of the value of these risk
reductions ranges from less than $0.1 million to slightly over $8.0 million annually, depending on
the regulatory option considered and the approach used to estimate occurrence. Sensitivity analysis
of the values assigned to these avoided risks indicates that the highest total value may be about $16.0
million under the lognormal approach, if an MCL of 20 pCi/L is developed for uranium. The lowest
risk reduction values accrue for closure of the gross alpha loophole and the less stringent uranium
options under the direct proportions approach.
The value of the risk reductions is often less than the estimated compliance costs by an order
of magnitude or more. Compliance costs range from $2.5 million to over $150 million annually.
The options with the lowest and highest costs vary depending on the approach used for estimating
occurrence. In most cases, the lognormal approach leads to higher costs and larger risk reductions.
Use of the lognormal tends to increase the estimates of the number of systems out of compliance in
the larger size categories and to lead to higher estimates of baseline concentrations. However, in a
few cases the lognormal estimates are lower because data on which the distributions are based are
tightly clustered near zero with only a few higher observations, which generally lowers the
occurrence estimates.
The quantified costs and benefits can also be considered in terms of costs per cancer case
avoided (compliance costs divided by cases avoided) or as net benefits (the value of risk reductions
minus compliance costs) as illustrated in Exhibit 6-4 below. This exhibit suggests that the cost per
cancer case avoided exceeds $30 million for each option considered, and is greater than $60 million
in most cases. In contrast, the mean estimate of the value of avoiding fatal risks is about $5.8 million
per statistical case (as discussed in Chapter 3), suggesting that the costs of achieving the MCLs may
be greater than individuals' willingness to pay for these risk reductions. The estimated dollar value
of the risk reductions offsets the compliance costs to a small extent, with negative net benefits in all
cases. These calculations should be viewed with caution, however, because compliance costs may
be overstated, not all benefits are quantified, and the value of the risk reductions is uncertain, as
discussed elsewhere in this report.
6-6
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Industrial Economics, Incorporated: January 2000 Draft
Exhibit 6-4
COMPARISON OF QUANTIFIED ANNUAL COSTS AND BENEFITS
(community water systems)
Regulatory Option
Directly Proportional
Cost per
Cancer Case
Avoided 3
Net Benefits4
Lognormal Distribution
Cost per
Cancer Case
Avoided 3
Net Benefits '
Compliance with existing MCLs after closing monitoring loopholes (combined radium = 5 pCi/L, gross
alpha = 15 pCi/L)1
Eliminate gross alpha monitoring
loophole only
Eliminate combined radium
monitoring loophole only
Eliminate both loopholes 2
$62.5 million
$69.7 million
$69.4 million
($2.3 million)
($20.4 million)
($20.9 million)
$98.6 million
$7 1.9 million
$83.6 million
($33.2 million)
($36.6 million)
($68.5 million)
Compliance with revised MCL options2
Revise gross alpha MCL to 10
pCi/L net of radium-226 only
Limit radium-228 at 3 pCi/L
within combined radium MCL of
5 pCi/L only
Revise both gross alpha and
radium MCLs 2
$118.3 million
$8 1.4 million
$105.8 million
($60.6 million)
($38.7 million)
($79.4 million)
$102.3 million
$60.2 million
$77.5 million
($68.9 million)
($35.3 million)
($79.4 million)
Compliance with new uranium MCL options
Establish uranium MCL at 20
pCi/L (20 A/g/L)
Establish uranium MCL at 40
pCi/L (40 Mg/L)
Establish uranium MCL at 80
pCi/L (80 Mg/L)
$210.7 million
$167.5 million
$500.0 million
($3 1.0 million)
($6.6 million)
($5.0 million)
$74.1 million
$44.2 million
$29.0 million
($148.8 million)
($62.0 million)
($25.9 million)
Notes:
See text for discussion of non-quantified impacts and limitations in the analysis.
1 . Compared to full compliance baseline (i.e., occurrence data are adjusted to eliminate illegal noncompliance).
2. Compared to revised baseline (i.e., occurrence data are adjusted to eliminate legal noncompliance).
3. Cost estimates divided by total number of cases avoided from Exhibits 6-2 and 6-3.
4. Best estimates of value of avoided cases minus cost estimate from Exhibits 6-2 and 6-3; parentheses indicate negative numbers.
6-7
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Industrial Economics, Incorporated: January 2000 Draft
IMPLICATIONS AND KEY LIMITATIONS
These results are preliminary and subject to uncertainties that are discussed in detail in the
preceding chapters, as are EPA's plans for conducting additional research to address related
concerns. When all of the sources of uncertainty are taken into account, EPA believes that costs may
exceed benefits by a smaller amount than indicated by the above exhibits, and in some cases actual
costs and benefits may be relatively equal.
The discussion of uncertainty in Chapter Four suggests that the costs may be overstated. The
cost estimates summarized in the above exhibits assume that systems will often install treatment to
comply with the MCLs, while recent research suggests that they will generally select less costly
options such as blending water from contaminated and uncontaminated sources. The benefits
associated with risk reductions may be understated because the analysis does not consider the effects
of treatment on other contaminants present nor does it include the effects of uranium on the kidneys.
In addition, the risk coefficients used in the analysis are highly uncertain. This report also does not
consider benefits other than human health risk reductions, such as improvements (if any) in the
aesthetic qualities of the water (taste, odor, color) or reduced materials damages that may be
associated with the strategies used to comply with the revised regulations.
The analysis also does not include consideration of other impacts that will have more
uncertain effects on the relationship between costs and benefits. The exhibits do not include
estimates of costs and risk reductions for systems serving populations more than one million or on
non-transient non-community systems. This report also does not consider the impact of the
regulations on other programs, such as the use of MCLs in site clean-up decisions.
Finally, the preliminary analysis does not quantify the impacts of the regulatory options on
certain groups of concern. It does not address health risks posed to children, members of low income
or minority groups, or sensitive sub-populations. It also does not address unfunded mandates or
options for further minimizing costs for small systems. All of these factors are of interest to
decision-makers and will be taken into account in the final selection of the regulatory options to be
implemented.
6-8
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Industrial Economics, Incorporated: January- 2000 Draft
Appendix A
NUMBER OF WATER SYSTEMS AND POPULATION SERVED
(Community and Non-Transient Non-Community Water Systems)
-------
Industrial Economics, Incorporated: January 2000 Draft
Appendix A
DATA ON WATER SYSTEMS AND POPULATIONS SERVED
The following pages provide the detailed data on the water system characteristics used in the
preliminary economic analysis. These exhibits are based on validated 1997 data from EPA's Safe
Drinking Water Information System (SDWIS) provided in February 1999.' We exclude systems
classified as "other" ownership from these exhibits because the validation effort indicated that these
systems are most likely inactive. We also exclude systems serving fewer than 25 people because
they do not meet the definition of public water systems subject to the regulations. Community water
systems serving more than one million persons are assessed separately in this analysis, and hence
are also excluded from the exhibits (no non-transient non-community systems serve populations
greater than one million). Because the data on population served includes only retail populations,
we include systems relying on purchased water to avoid leaving out the portion of the population
that depends on these systems.
1. Exhibits A-l and A-2 provide data on community water systems organized
by water source and system size class, including the number of systems and
the average population served.
2. Exhibits A-3 and A-4 provide the same data for non-transient, non-
community water systems.
3. Exhibit A-5 provides data on non-transient, non-community systems
organized by state, number of ground water systems, number of surface water
systems, and population served by each type.
1 International Consultants, Incorporated, Drinking Water Baseline Handbook: First Edition
(Draft), prepared for the U.S. Environmental Protection Agency, March 3, 1999, Exhibits B4.1.1(a),
B4.1.2(a), B4.2.1(a), and B4.2.1(b).
A-l
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Industrial Economics, Incorporated: January 2000 Draft
Exhibit A-l
COMMUNITY WATER SYSTEMS: NUMBER OF SYSTEMS
(1997 SDVVIS data)
Population Categories
System Type
Ground Water
Public
Private
Purchased-public
Purchased-private
Surface Water
Public
Private
Purchased-public
Purchased-private
TOTAL
25-100
13,848
1,202
12,361
114
171
942
151
307
185
299
14,790
101-500
14,654
4,104
9,776
427
347
1,967
385
389
687
506
16,621
501-1,000
4,645
2,574
1,705
265
101
1,167
331
111
511
214
5,812
1,001-3,300
5,674
3,792
1,531
272
79
2,435
928
211
1,015
281
8,109
3,301-
10,000
2,472
1,916
459
84
13
1,821
882
107
720
112
4,293
10,001-
50,000
1,279
997
243
36
3
1,528
810
113
560
45
2,769
50,001-
100,000
139
113
24
1
1
268
146
33
86
3
403
100,001-
1,000,000
70
52
14
4
0
247
161
39
40
7
317
Total
42,781
14,750
26,113
1,203
715
10,375
3,794
1,310
3,804
1,467
53,156
A-2
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Industrial Economics, Incorporated: January 2000 Draft
Exhibit A-2
COMMUNITY WATER SYSTEMS: AVERAGE NUMBER OF PERSONS SERVED
(1997 SDWIS data)
Population Categories
System Type
Ground Water
Public
Private
Purchased-public
Purchased-private
Surface Water
Public
Private
Purchased-public
Purchased-private
25-100
61
65
60
71
64
62
55
59
71
64
101-500
249
290
230
282
271
283
300
259
297
270
501-1,000
737
745
721
741
772
751
769
770
745
722
1,001-3,300
1,858
1,885
1,805
1,809
1,775
1,982
2,064
1,975
1,935
1,879
3,301-
10,000
5,739
5,758
5,669
5,609
6,317
5,964
6,012
6,182
5,928
5,603
10,001-
50,000
21,168
20,875
22,562
20,076
18,654
22,656
23,080
25,438
21,712
19,776
50,001-
100,000
67,661
67,543
67,670
96,000
52,500
68,441
69,224
67,985
67,082
74,293
100,001-
1,000,000
225,473
213,794
297,449
125,381
0
247,380
257,483
277,442
193,330
156,384
A-3
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Industrial Economics, Incorporated: January 2000 Draft
Exhibit A-3
NON-TRANSIENT NON-COMMUNITY WATER SYSTEMS: NUMBER OF SYSTEMS
(1997 SDWIS data)
Population Categories
System Type
Ground Water
Public
Private
Purchased-public
Purchased-private
Surface Water
Public
Private
Purchased-public
Purchased-private
TOTAL
25-100
9,169
1,704
7,432
11
22
209
48
78
14
69
9,378
101-500
6,873
3,109
3,731
16
17
223
34
119
27
43
7,096
501-1,000
1,912
1,145
752
8
7
77
II
47
7
12
1,989
1,001-3,300
675
327
342
6
0
67
17
33
6
11
742
3,301-
10,000
59
21
33
5
0
16
1
8
3
4
75
10,001-
50,000
11
5
2
3
1
4
0
0
3
1
15
50,001-
100,000
0
0
0
0
0
1
0
0
1
0
1
100,001-
1,000,000
0
0
0
0
0
1
0
0
1
0
1
Total
18,699
6,311
12,292
49
47
598
111
285
62
140
19,297
A-4
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Industrial Economics, Incorporated: January 2000 Draft
Exhibit A-4
NON-TRANSIENT NON-COMMUNITY WATER SYSTEMS: AVERAGE NUMBER OF PERSONS SERVED
(1997 SDWIS data)
Population Categories
System Type
Ground Water
Public
Private
Purchased-public
Purchased-private
Surface Water
Public
Private
Purchased-public
Purchased-private
25-100
53
55
53
59
34
48
45
56
47
43
101-500
257
281
238
274
221
264
258
261
248
285
501-1,000
720
705
741
835
705
787
801
785
750
800
1,001-3,300
1,626
1,517
1,717
2,418
0
1,845
2,125
1,673
2,080
1,803
3,301-
10,000
5,125
6,000
4,563
5,160
0
5,256
4,860
5,342
5,160
0
10,001-
50,000
18,348
15,525
15,200
26,267
15,000
29,500
0
0
33,333
18,000
50,001-
100,000
0
0
0
0
0
93,204
0
0
93,204
0
100,001-
1,000,000
0
0
0
0
0
0
0
0
152,079
0
A-5
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Industrial Economics, Incorporated: January- 2000 Draft
Exhibit A-5
NON-TRANSIENT NON-COMMUNITY WATER SYSTEMS BY STATE
(1997 SDWIS data)
State
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Number of Systems
Ground Water
46
0
214
57
1,017
133
444
76
1,115
291
14
265
445
692
133
66
80
234
344
495
227
1,718
429
Surface Water
8
0
9
60
52
26
0
1
1
9
2
9
11
4
2
2
26
12
3
2
4
0
6
Total Population Served
Ground Water
21,182
0
100,287
13,528
359,033
34,884
101,172
23,915
285,998
80,240
7,437
68,195
142,645
158,048
35,715
23,002
21,620
88,070
67,436
142,171
67,647
344,654
43,394
Surface Water
11,102
0
6,652
3,869
1 12,956
16,557
0
1,300
250
5,367
930
1,570
9,816
1,569
2,000
637
1 1,394
11,036
1,370
572
735
0
2,159
A-6
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Industrial Economics, Incorporated: January 2000 Draft
Exhibit A-5
NON-TRANSIENT NON-COMMUNITY WATER SYSTEMS BY STATE
(1997 SDWIS data)
State
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Number of Systems
Ground Water
124
227
213
189
91
414
999
149
693
655
22
1,116
123
332
1,249
69
247
25
58
747
52
0
649
Surface Water
0
6
5
0
8
0
3
7
32
11
10
15
9
9
25
0
11
4
10
81
10
0
15
Total Population Served
Ground Water
88,119
76,360
38,382
26,219
28,497
75,905
274,557
38,101
248,223
198,136
2,349
276,441
20,419
67,531
480,283
25,121
71,219
3,072
11,010
253,447
20,969
0
288,913
Surface Water
0
1,945
620
0
11,420
0
3,139
1,452
19,429
9,506
2,096
10,004
1,461
4,868
15,854
0
13,926
375
16,358
96,945
21,571
0
74,318
A-7
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Industrial Economics, Incorporated: January 2000 Draft
Exhibit A-5
NON-TRANSIENT NON-COMMUNITY WATER SYSTEMS BY STATE
(1997 SDWIS data)
State
Washington
West Virginia
Wisconsin
Wyoming
Total
Number of Systems
Ground Water
285
178
1,049
80
18,570
Surface Water
17
19
0
19
575
Total Population Served
Ground Water
69,964
38.774
214,561
13,733
5,180,578
Surface Water
170,466
15,483
0
5,713
698,790
Notes:
Excludes systems serving less than 25 people; includes systems relying primarily on purchased water.
Surface water systems include those using ground water under the influence of surface water.
The Drinking Water Baseline Handbook, which contain state and national summaries of the SDWIS system and
population counts, is currently undergoing revision. The totals in this table may not match the national totals in
Exhibits A-3 and A-4.
Source:
International Consultants, Incorporated, Drinking Water Baseline Handbook: First Edition (Draft), prepared for
the U.S. Environmental Protection Agency, March 3, 1999.
A-8
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Industrial Economics, Incorporated: January 2000 Draft
Appendix B
HISTOGRAMS OF OCCURRENCE DATA
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Industrial Economics, Incorporated: January 2000 Draft
Appendix B
HISTOGRAMS OF OCCURRENCE DATA
The following pages provide graphs of the frequency distributions of the National Inorganics
and Radionuclides Survey (NIRS) data used in the occurrence analysis (as described in Chapter
Two). For drinking water systems serving 25-500 persons and 501-3,300 persons, we include three
histograms for both combined radium and gross alpha: the original NIRS data, the initial baseline
data (adjusted to eliminate illegal noncompliance), and the revised baseline (adjusted to eliminate
legal noncompliance). For uranium, we provide histograms of the original NIRS data only; because
uranium is not currently regulated in drinking water systems, there are no adjustments for illegal or
legal noncompliance.
We do not include graphs of the occurrence data for systems serving more than 3,300 persons
because the sample sizes for the two largest size categories in NIRS are not large enough to be
representative at the national level. We also exclude graphs of uranium occurrence in surface water,
because NIRS reports data for ground water systems only. However, because we assume that
uranium levels in surface water are one-third the levels of uranium in groundwater (as described in
Chapter Two), the histograms for surface water would have the same shape as the graphs for
uranium in groundwater, but would be centered around a lower activity level; i.e., the whole graph
would shift to the left.
The graphs in this Appendix do not include censored data points, i.e., those reported in NIRS
as less than the Minimum Reporting Limit (MRL) for all radionuclides included in the calculation
of activity levels. If included in the histograms, these data points would be clustered at the left side
of the distributions. For each graph, we indicate the number of censored systems and the percentage
of total systems that the censored data points represent.
It should be noted that the graphs in this Appendix are scaled differently in order to fit them
on a page. This change in scale means that care must be taken when comparing the graphs. For
example, when compared on the same scale, the initial baseline and revised baseline distributions
for a given radionuclide and system size category have shorter right-hand tails than the distribution
of the original NIRS data.
B-l
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Industrial Economics, Incorporated: January 2000 Draft
The remainder of this Appendix includes the following.
1. Exhibit B-l(a) presents the original NIRS, initial baseline, and revised
baseline occurrence distributions for combined radium in systems serving
populations of 25-500 persons. Exhibit B-l(b) provides the same graphs for
systems serving populations of 501 to 3,300 persons.
2. Exhibits B-2(a) and B-2(b) include the analogous histograms for gross alpha.
3. Exhibit B-3 provides histograms of the original NIRS data for uranium.
B-2
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Industrial Economics, Incorporated: January- 2000 Draft
Exhibit B-l(a)
DISTRIBUTION OF COMBINED RADIUM ACTIVITY LEVELS IN NIRS
(population <=500)
Note: Censored data points (i.e., those reported in NIRS as less than the Minimum Reporting
Limit (MRL) for both radium-226 and radium-228) are not depicted in these graphs. For combined
radium, the values of these censored data range from zero to 1.18 (the sum of the MRLs for
radium-226 and radium-228). Of the 671 data points for NIRS systems serving a population of less
than or equal to 500 people, 390 (58.1 percent) are censored. Note that these graphs are scaled
differently.
tn
CO
>»
CO
60
50
40 -.
Original NIRS
30
20
10
--Hklki-iulu
in
in
CM
Activity Level (pCi/L)
B-3
-------
Industrial Economics, Incorporated: January 2000 Draft
(0
E
.2
W
"5
60
50 -
40 -
30 -
20 -
10 -
o
c
-
I
' £
I
I
Initial Baseline*
In
Illlllllli Ik LI ..i .
^ c^ ^^ co ^^ TJ* 1/5 (O r^ co 05 O) ^^
Activity Level (pCi/L)
* Adjusted to eliminate illegal noncompliance.
Revised Baseline**
60
(0
0)
50 .
40
>, 30 4-
[/>
O 20
tt:
10 4-
o
I lit. I... . -.1.
T- CM CN CO CO
Activity Level (pCi/L)
* Adjusted to eliminate legal noncompliance.
B-4
-------
Industrial Economics, Incorporated: January 2000 Draft
Exhibit B-l(b)
DISTRIBUTION OF COMBINED RADIUM ACTIVITY LEVELS IN NIRS
(population 501-3,300)
Note: Censored data points (i.e., those reported in NIRS as less than the Minimum Reporting
Limit (MRL) for both radium-226 and radium-228) are not depicted in these graphs. For combined
radium, the values of these censored data range from zero to 1.18 (the sum of the MRLs for
radium-226 and radium-228). Of the 231 data points for NIRS systems serving a population of 501
- 3,300 people, 130 (56.3 percent) are censored. Note that these graphs are scaled differently.
35
Original NIRS
30 -.
co 254-
« 20
CO
<0 15 --
n-
O
!l La
r 10 co f^* oo en ^D ^* CN co
V- ^ T ^
Activity Level (pCi/L)
B-5
-------
Industrial Economics, Incorporated: January 2000 Draft
CO
t5
CO
0
35 -
30 -
25 -
20 -
15 -
10 -
5 -
0 -
c
Initial Baseline*
lllllll.lilii i li . . . .
OOT-'T^ CNCsicOfO ^^lOlri
Activity Level (pCi/L)
* Adjusted to eliminate illegal noncompliance.
CO
o>
CO
CO
*0
10 .
9 -
8 -
7 -
6 -
5 -
4 -
r»
Revised Baseline**
i
;
I
Activity Level (pCi/L)
**Adjusted to eliminate legal noncompliance.
B-6
-------
Industrial Economics, Incorporated: January 2000 Draft
Exhibit B-2(a)
DISTRIBUTION OF GROSS ALPHA ACTIVITY LEVELS IN NIRS
(population <=500)
Note: To adjust the gross alpha values reported for a system in NIRS to meet the regulatory
definitions used in this analysis, we subtract the NIRS uranium value from the gross alpha value and
add three times the radium-228 value (to estimate the occurrence of radium-224 and its daughter
products). To calculate net gross alpha for the revised baseline, we then subtract radium-226.
Censored data points (i.e., those reported in NIRS as less than the Minimum Reporting Limit (MRL)
for all of the radionuclide components of gross alpha) are not depicted in these graphs. For gross
alpha, the values of these censored data points fall below 5.6 pCi/L. Of the 660 original gross alpha
and initial baseline data points for NIRS systems serving a population of less than or equal to 500
people, 227 (34.4 percent) are censored. Of the 659 revised baseline data points for NIRS systems
in this population size category, 182 (27.6 percent) are censored. Note that these graphs are scaled
differently.
Original Gross Alpha (NIRS gross alpha, minus
uranium, plus 3*radium-228)
(0
0>
w
CO
h^
o
M.
w
100 -,
90 -
80 -
70 -
60 -
50 -
40 -
30 -
20 -
10 -
0 -
o
-
t^L
coc\imco-«-ifrr-or>cocDO)CNmco
Activity Level (pCi/L)
B-7
-------
Industrial Economics, Incorporated: January 2000 Draft
Initial Baseline*
100
Activity Level (pCi/L)
CN CM CM
* Adjusted to eliminate illegal noncompliance.
in
40
Revised Baseline
**
Activity Level (pCi/L)
**Adjusted to eliminate legal noncompliance. Excludes radium-226.
B-8
-------
Industrial Economics. Incorporated: January- 2000 Draft
Exhibit B-2(b)
DISTRIBUTION OF GROSS ALPHA ACTIVITY LEVELS IN MRS
(population 501-3,300)
Note: To adjust the gross alpha values reported for a system in NIRS to meet the regulatory
definitions used in this analysis, we subtract the NIRS uranium value from the gross alpha value and
add three times the radium-228 value (to estimate the occurrence of radium-224 and its daughter
products). To calculate net gross alpha for the revised baseline, we then subtract radium-226.
Censored data points (i.e., those reported in NIRS as less than the Minimum Reporting Limit (MRL)
for all of the radionuclide components of gross alpha) are not depicted in these graphs. For gross
alpha, the values of these censored data points fall below 5.6 pCi/L. Of the 229 original gross alpha
and initial baseline data points for NIRS systems serving a population of 501 to 3,300 people, 78
(34.1 percent) are censored. Of the 229 revised baseline data points for NIRS systems in this
population size category, 61 (26.6 percent) are censored. Note that these graphs are scaled
differently.
Original Gross Alpha (NIRS gross alpha, minus
uranium, plus 3*radium-228)
CM
Activity Level (pCi/L)
B-9
-------
Industrial Economics, Incorporated: January 2000 Draft
30
25
20 ..
Q)
CO
> «*-
O
%
10
5 .
JH
InU
oh-.
Initial Baseline*
I I I II I I I III I I I I I
^}* **f if) (O f** 00 O> O5 O
Activity Level (pCi/L)
Adjusted to eliminate illegal noncompliance.
30
25 .
20 .
CO
CO
»-
O
10 .
5 .
ililJil,
Revised Baseline**
ui,
ill illlii li i 11 HI ii
Activity Level (pCi/L)
in
in (si o>
C3 ^ W
* Adjusted to eliminate legal noncompliance. Excludes radium-226.
B-10
-------
Industrial Economics, Incorporated: January 2000 Draft
Exhibit B-3
DISTRIBUTION OF URANIUM ACTIVITY LEVELS IN NIRS
Note: Censored data points (i.e., those reported in NIRS as less than the Minimum Reporting
Limit (MRL)) are not depicted in these graphs. For uranium, the values of these censored data range
from zero to 0.08 (the MRL for uranium). Of the 662 data points for NIRS systems serving a
population of less than or equal to 500 people, 185 (27.9 percent) are censored. Of the 232 data
points for NIRS systems serving a population of 501 - 3,300 people, 69 (29.7 percent) are censored.
Note that these graphs are scaled differently.
Exhibit B-3(a): Population <=500
# of Systems
Original NIRS
100
90 .
80
70 .
60
50
40 .
30
20
10
Activity Level (pCi/L)
Exhibit B-3(b): Population 501-3300
Original NIRS
II. .1 ... .
co o> eg in to
o> o «- to
Activity Level (pCi/L)
B-ll
-------
Industrial Economics, Incorporated: January- 2000 Draft
Appendix C
DETAILED RISK RESULTS FOR
COMMUNITY WATER SYSTEMS
-------
Industrial Economics, Incorporated: January 2000 Draft
Appendix C
DETAILED RISK RESULTS FOR COMMUNITY WATER SYSTEMS
Appendix C presents the risk results for community water systems by cancer type (nonfatal,
fatal, or total) and system size and type. Note that the tables indicate the risk reductions due solely
to treatment of the radionuclide directly addressed by the regulatory option; they do not consider the
incidental treatment of other radionuclides present.
Exhibit C-l presents estimates of the cancer risk reductions that result from closing the
monitoring loopholes; Exhibits C-2 through C-5 present anticipated cancer risk reductions from
changes to the MCLs. The tables presenting the risk results for the uranium MCLs provide separate
estimates for surface water and ground water systems (only ground water systems were considered
for the other regulatory options). The total number of cases avoided including the effects of
incidental treatment are provided in Chapter 3 of this report.
C-l
-------
Industrial Economics, Incorporated: January- 2000 Draft
Exhibit C-l
ANNUAL CANCER RISKS AVOIDED: CLOSING THE MONITORING LOOPHOLES
(Community Ground Water Svstems)
System Size
Class
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-50,000
50,001-
100,000
100,001-
1,000,000
All Systems
Cancer Type
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Directly Proportional
(statistical cases)
Radium
Loophole
0.005
0.002
0.008
0.023
0.010
0.033
0.006
0.002
0.009
0.019
0.008
0.026
0.025
0.010
0.035
0.048
0.020
0.067
0.017
0.007
0.023
0.028
0.011
0.039
0.170
0.070
0.240
Gross Alpha
Loophole
0.002
0.001
0.004
0.010
0.006
0.017
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.013
0.007
0.020
Lognormal Distribution
(statistical cases)
Radium
Loophole
0.006
0.002
0.008
0.025
0.010
0.035
0.013
0.005
0.018
0.040
0.016
0.056
0.053
0.022
0.075
0.102
0.042
0.144
0.035
0.015
0.050
0.059
0.025
0.084
0.334
0.138
0.471
Gross Alpha
Loophole
0.002
0.001
0.004
0.010
0.006
0.016
0.008
0.005
0.013
0.025
0.015
0.040
0.034
0.021
0.054
0.065
0.039
0.104
0.022
0.014
0.036
0.038
0.023
0.061
0.204
0.124
0.329
Notes:
1. Numbers in table represent the direct effects of closing a particular loophole (e.g., the column pertaining to closure of the
radium loophole refers to risk reductions from reduced Ra-226 and -228 only). Removal of other radionuclides present (i.e., gross
alpha in the case of the radium loophole) results in additional incremental risk reductions, ranging from 0.02 cases to 0.07 cases
nationally depending on the combination of regulatory options implemented.
2. Detail may not sum to total due to rounding.
C-2
-------
Industrial Economics, Incorporated: January 2000 Draft
Exhibit C-2
ANNUAL CANCER RISKS AVOIDED: ADJUSTING THE MCLs
(Community Ground Water Systems)
System Size
Class
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-50,000
50,001-
100,000
100,001-
1,000,000
All Systems
Cancer Type
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Directly Proportional
(statistical cases)
Radium-228
at 3 pCi/L
0.001
0.001
0.002
0.006
0.002
0.008
0.009
0.004
0.013
0.029
0.012
0.041
0.039
0.016
0.055
0.074
0.030
0.105
0.026
0.010
0.036
0.043
0.018
0.061
0.228
0.093
0.321
Gross Alpha
at 10 pCi/L
0.002
0.001
0.003
0.009
0.006
0.015
0.006
0.004
0.011
0.020
0.013
0.033
0.027
0.017
0.044
0.051
0.033
0.084
0.018
0.011
0.029
0.030
0.019
0.049
0.163
0.105
0.267
Lognormal Distribution
(statistical cases)
Radium-228
at 3 pCi/L
0.002
0.001
0.003
0.008
0.003
0.012
0.013
0.005
0.019
0.041
0.017
0.058
0.055
0.022
0.077
0.105
0.043
0.148
0.037
0.015
0.051
0.061
0.025
0.086
0.323
0.131
0.453
Gross Alpha at
lOpCi/L
0.003
0.002
0.004
0.011
0.007
0.019
0.011
0.007
0.018
0.033
0.021
0.055
0.045
0.029
0.074
0.086
0.055
0.140
0.030
0.019
0.049
0.050
0.032
0.082
0.268
0.172
0.440
Notes:
1 . Numbers in table represent the direct effects of adjusting a particular MCL (i.e., the effect of changing the gross alpha MCL
on risks from gross alpha only). Adjusting these MCLs results in additional incremental risk reductions, ranging from 0. 1 8 cases
to 0.26 cases annually, depending on the combination of regulatory options implemented.
2. Detail may not sum to total due to rounding.
C-3
-------
Industrial Economics. Incorporated: January 2000 Draft
Exhibit C-3 ll
ANNUAL CANCER RISKS AVOIDED: LIMITING URANIUM TO 20 pCi/L and 20 ^g/L |
(Community Water Systems)
System Size
Class
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-50,000
50,001-
100,000
100,001-
1,000,000
All Systems
Cancer Type
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Directly Proportional
(statistical cases)
Ground Water
0.010
0.005
0.015
0.044
0.024
0.067
0.002
0.001
0.003
0.006
0.003
0.009
0.008
0.004
0.012
0.015
0.008
0.023
0.005
0.003
0.008
0.009
0.005
0.013
0.098
0.053
0.151
Surface Water
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Lognormal Distribution
(statistical cases)
Ground Water
0.015
0.008
0.023
0.064
0.035
0.098
0.041
0.022
0.064
0.128
0.069
0.197
0.172
0.093
0.265
0.328
0.178
0.506
0.114
0.062
0.176
0.191
0.104
0.295
1.053
0.570
1.623
Surface Water
0.000
0.000
0.000
0.002
0.001
0.003
0.002
0.001
0.003
0.012
0.006
0.018
0.027
0.085
0.046
0.130
0.045
0.024
0.069
0.149
0.081
0.230
0.322
0.174
0.496
Note: Detail mav not sum to total due to rounding. |
C-4
-------
Industrial Economics, Incorporated: January 2000 Draft
Exhibit C-4
ANNUAL CANCER RISKS AVOIDED: LIMITING URANIUM TO 40 pCi/L and 40//g/L
(Community Water Systems)
System Size
Class
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-
50,000
50,001-
100,000
100,001-
1,000,000
All Systems
Cancer Type
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Directly Proportional
(statistical cases)
Ground Water
0.004
0.002
0.007
0.019
0.010
0.029
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.023
0.013
0.036
Surface Water
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Lognormal Distribution
(statistical cases)
Ground Water
0.012
0.006
0.018
0.052
0.028
0.080
0.031
0.017
0.048
0.096
0.052
0.148
0.129
0.070
0.198
0.246
0.133
0.379
0.085
0.046
0.132
0.143
0.078
0.221
0.793
0.430
1.223
Surface Water
0.000
0.000
0.000
0.002
0.001
0.002
0.001
0.001
0.002
0.008
0.004
0.012
0.017
0.009
0.026
0.055
0.030
0.084
0.029
0.016
0.045
0.096
0.052
0.148
0.208
0.112
0.320
Note: Detail may not sum to total due to roundine.
C-5
-------
Industrial Economics, Incorporated: January- 2000 Draft
Exhibit C-5
ANNUAL CANCER RISKS AVOIDED: LIMITING URANIUM TO 80 pCi/L and 80 //g/L
(Community Water Systems)
System Size
Class
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-
50,000
50.001-
100,000
100,001-
1,000,000
All Systems
Cancer Type
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Fatal Cancer
Nonfatal Cancer
Total Cancer
Directly Proportional
(statistical cases)
Ground Water
0.001
0.000
0.001
0.003
0.001
0.004
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.003
0.002
0.005
Surface Water
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Lognormal Distribution
(statistical cases)
Ground Water
0.009
0.005
0.014
0.039
0.021
0.059
0.021
0.011
0.033
0.065
0.035
0.101
0.088
0.048
0.135
0.167
0.091
0.258
0.058
0.032
0.090
0.098
0.053
0.150
0.545
0.295
0.840
Surface Water
0.000
0.000
0.000
0.001
0.001
0.002
0.001
0.000
0.001
0.004
0.002
0.007 1
o.oio 1
0.005 |
0.015 '
0.032
0.017
0.049
0.017
0.009
0.026
0.056
0.031
0.087
0.122
0.066
0.188
Note: Detail may not sum to total due to rounding. ||
C-6
-------
Industrial Economics, Incorporated: January 2000 Draft
Appendix D
DECISION TREES FOR COMMUNITY WATER SYSTEMS
-------
Industrial Economics, Incorporated: January- 2000 Draft
Appendix D
DECISION TREES FOR COMMUNITY WATER SYSTEMS
Appendix D presents the decision trees that are used in the cost model to estimate the
probability that community water systems will undertake different types of compliance actions,
provided by William Labiosa of EPA/OGWDW on November 22 and 23, 1999. Separate decision
trees were developed for gross alpha and combined radium and for uranium, based on system size,
and removal rate. Exhibit D-l presents the decision tree for removal of gross alpha and combined
radium in ground water systems; Exhibits D-2 and D-3 present the decision trees for removal of
uranium in ground water and surface water systems, respectively. A description of how EPA used
these decision trees in the cost analysis is provided in Chapter 4 of this report.
D-l
-------
Industrial Economics, Incorporated: January 2000 Draft
Exhibit U-l
DECISION TREE FOR COMBINED RADIUM AND GROSS ALPHA (Ground Water Systems)
Decision Tree for Systems Requiring Max Removal
Technology
Water Softening/
Iron Removal
(MAX)1
Enhanced Lime
Softening
(MAX)
Greensand
Filtration
(MAX)
Poinl-of-Use
Reverse
Osmosis
Point-of-Use
Cation
Exchange
Regionalization/
Blending/
Other
Alternative
Source
Totals
Population Size Category
1 (25-100)
2(101-500)
3(501-1,000)
4(1,001-3,300)
5(3,301-10,000)
6(10,001-50,000)
7 (50,001-100,000)
8(100,001-
1 million)
56%
56%
66%
66%
66%
66%
66%
66%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
5%
5%
0%
0%
0%
0%
0%
0%
5%
5%
0%
0%
0%
0%
0%
0%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
100%
100%
100%
100%
100%
100%
100%
100%
Decision Tree Tor Systems Requiring 80% Removal
Technology
WS/IR(80%)
ELS(80%)
GS(80%)
POURO
POU CX
Regionalize/Blend
Alt. Source | Totals
Population Size Category
1 (25-100)
2(101-500)
3(501-1,000)
4(1,001-3,300)
5(3301-10,000)
6(10,001-50,000)
7(50,001-100,000)
8(100,001-
1 million)
56%
56%
66%
66%
66%
66%
66%
66%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
5%
5%
0%
0%
0%
0%
0%
0%
5%
5%
0%
0%
0%
0%
0%
0%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
100%
100%
100%
100%
100%
100%
100%
100%
Decision Tree for Systems Requiring 50% Removal
Technology
WS/IR(50%)
ELS(50%) GS(50%) POU RO POD CX
Regionalize/Blend
Alt. Source
totals
Population Size Category
1 (25-100)
2(101-500)
3(501-1,000)
4(1,001-3^00)
5 (3301-lOjOOO)
6(10,001-50,000)
7 (50,001-100,000)
8(100,001-
1 million)
46%
46%
46%
46%
66%
66%
66%
66%
0%
0%
0%
0%
0%
0%
0%
0%
10%
10%
10%
10%
0%
0%
0%
0%
5%
5%
5%
5%
0%
0%
0%
0%
5%
5%
5%
5%
0%
0%
0%
0%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
100%
100%
100%
100%
100%
100%
100%
100%
Decision Tree for Systems Requiring 30% Removal
Technology
WS/IR(30%)
ELS(30%)
GS(30%)
POURO
POU CX
Regionalize/Blend
Alt Source
Totals
Population Size Category
1 (25-100)
2(101-500)
3 (501-1,000)
4(1,001-3300)
5 (3301-10,000)
6 (10,001-50,000)
7 (50,001-100,000)
8(100,001-
1 million)
46%
46%
36%
36%
66%
66%
66%
66%
0%
0%
0%
0%
0%
0%
0%
0%
10%
10%
20%
20%
0%
0%
0%
0%
5%
5%
5%
5%
0%
0%
0%
0%
5%
5%
5%
5%
0%
0%
0%
0%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
17%
100%
100%
100%
100%
100%
100%
100%
100%
Notes:
_' Water softening/iron removal includes treatment technologies such as ion exchange, oxidation/filtration, reverse osmosis, and lime softening.
D-2
-------
Industrial Economics. Incorporated: January 2(1
Exhibit l)-2
DECISION TREE FOR URANIUM (Ground Water Systems)
Decision Tree for Systems Requiring Max Removal
Technology
Population Size Category
1 (2S-IOO)
2 (101-500)
3(501-1,000)
4(1,001-3,300)
S (3,301-10,000)
6(10,001-50,000)
7 (50,001-100,000)
8(100,001-
1 million)
Water Softening/
Iron Removal
(MAX)1
56%
56%
66%
66%
66%
66%
66%
66%
Activated
Alumina
(MAX)
0%
0%
0%
0%
0%
0%
0%
0%
Enhanced
Coagulation/
Filtration
(MAX)
0%
0%
0%
0%
0%
0%
0%
0%
Point-of-llse
Reverse
Osmosis
5%
5%
0%
0%
0%
0%
0%
0%
Point-of-llse
Anion Exchange/
Activated
Alumina
5%
5%
0%
0%
0%
0%
0%
0%
Regionalizalion/
Blending/
Other
17%
17%
17%
17%
17%
17%
17%
17%
Alternative
Source
17%
17%
17%
17%
17%
17%
17%
17%
Totals
100%
100%
100%
100%
100%
100%
100%
100%
Decision Tree for Systems Requiring 80% Removal
Technology
Population Sizt Category
1 (25-100)
2 (101-500)
3(501-1,000)
4(1,001-3,300)
5 (3301-10,000)
6(10,001-50,000)
7 (50,001-100,000)
8(100,001-
1 million)
WS/IR(80)
56%
56%
66%
66%
66%
66%
66%
66%
AA(80)
0%
0%
0%
0%
0%
0%
0%
0%
EC/F(80)
0%
0%
0%
0%
0%
0%
0%
0%
POURO
5%
5%
0%
0%
0%
0%
0%
0%
POU AX/AA
5%
5%
0%
0%
0%
0%
0%
0%
Regionalize/Blend
17%
17%
17%
17%
17%
17%
17%
17%
Alt. Source
17%
17%
17%
17%
17%
17%
17%
17%
Totals
100%
100%
100%
100%
100%
100%
100%
100%
Decision Tree for Systems Requiring 50% Removal
Technology
Population Size Category
1 (25-100)
2(101-500)
3(501-1,000)
4(1,001-3,300)
5 (3,301-10,000)
6(10,001-50,000)
7 (50,001-100,000)
8 (100,001-
1 million)
WS/IR(50)
56%
56%
66%
66%
66%
66%
66%
66%
AA(50)
0%
0%
0%
0%
0%
0%
0%
0%
EC/F(50)
0%
0%
0%
0%
0%
0%
0%
0%
POURO
5%
5%
0%
0%
0%
0%
0%
0%
POU AX/AA
5%
5%
0%
0%
0%
0%
0%
0%
Regionalize/Blend
17%
17%
17%
17%
17%
17%
17%
17%
Alt. Source
17%
17%
17%
17%
17%
17%
17%
17%
Totals
100%
100%
100%
100%
100%
100%
100%
100%
Decision Tree for Systems Requiring 30% Removal
Technology
WS/IRI30)
Population Size Category
1 (25-100)
2(101-500)
3(501-1,000)
4(1,001-3,300)
5(3^01-10,000)
6(10,001-50,000)
7 (50,001-100,000)
8(100,001-
1 million)
56%
56%
66%
66%
66%
66%
66%
66%
AA(30)
0%
0%
0%
0%
0%
0%
0%
0%
EC/F(30)
0%
0%
0%
0%
0%
0%
0%
0%
POURO
5%
5%
0%
0%
0%
0%
0%
0%
POU AX/AA
5%
5%
0%
0%
0%
0%
0%
0%
Regionalize/Blend
17%
17%
17%
17%
17%
17%
17%
17%
Alt. Source
17%
17%
17%
17%
17%
17%
17%
17%
Totals
100%
100%
100%
100%
100%
100%
100%
100%
Notes:
1 Water softening/iron removal includes treatment technologies such as ion exchange, oxidation/filtration, reverse osmosis, and lime softening.
D-3
-------
Industrial Economics, Incorporated: January 200(1 Draft
Exhibit D-3
DECISION TREE FOR URANIUM (Surface Water Systems)^
Decision Tree Tor Systems Requiring Max Removal
Technology
Size Category
1 (25-100)
2(101-500)
3(501-1,000)
4(1,001-3300)
5 (3301-10,000)
6(10,001-50,000)
7 (50,001-100,000)
8(100,001-
1 million)
Water Softening/
Iron Removal
(MAX)1
51%
51%
16%
10%
10%
0%
0%
0%
Activated
Alumina
(MAX)
0%
0%
0%
0%
0%
0%
0%
0%
Enhanced
Coagulation/
Filtration
(MAX)
5%
5%
50%
56%
56%
66%
66%
66%
Point-of-Lse
Reverse
Osmosis
5%
5%
0%
0%
0%
0%
0%
0%
Point-of-Use
Anion Exchange/
Activated
Alumina
5%
5%
0%
0%
0%
0%
0%
0%
Regionalization/
Blending/
Other
17%
17%
17%
17%
17%
17%
17%
17%
Alternative
Source
17%
17%
17%
17%
17%
17%
17%
17%
Totals
100%
100%
100%
100%
100%
100%
100%
100%
Decision Tree for Systems Requiring 80% Removal
Technology
Size Category
1 (25-100)
2(101-500)
3(501-1,000)
4(1,001-3300)
5 (3301-10,000)
6(10,001-50,000)
7 (50,001-100,000)
8 (100,001-
I million)
WS/IR(80)
51%
51%
16%
10%
10%
0%
0%
0%
AA(80)
0%
0%
0%
0%
0%
0%
0%
0%
EC7F(80)
5%
5%
50%
56%
56%
66%
66%
66%
POU RO
5%
5%
0%
0%
0%
0%
0%
0%
POU AX/AA
5%
5%
0%
0%
0%
0%
0%
0%
Regionalize/Blend
17%
17%
17%
17%
17%
17%
17%
17%
All. Source
17%
17%
17%
17%
17%
17%
17%
17%
Totals
100%
100%
100%
100%
100%
100%
100%
100%
Decision Tree for Systems Requiring 50% Removal
Technology
Size Category
1 (25-100)
2 (101-500)
3 (501-1,000)
4(1,001-3300)
5 (3301-10,000)
6(10,001-50,000)
7 (50,001-100,000)
8(100,001-
1 million)
WS/IR(50)
51%
51%
16%
10%
10%
0%
0%
0%
AA(50)
0%
0%
0%
0%
0%
0%
0%
0%
EC/F(50)
5%
5%
50%
56%
56%
66%
66%
66%
POURO
5%
5%
0%
0%
0%
0%
0%
0%
POU AX/AA
5%
5%
0%
0%
0%
0%
0%
0%
Regionalize/Blend
17%
17%
17%
17%
17%
17%
17%
17%
Alt. Source
17%
17%
17%
17%
17%
17%
17%
17%
Totals
100%
100%
100%
100%
100%
100%
100%
100%
Decision Tree for Systems Requiring 30% Removal
Technology
Size Category
1 (25-100)
2(101-500)
3 (501-1,000)
4(1,001-3300)
5(3301-10,000)
6(10,001-50,000)
7(50,001-100,000)
8(100,001-
1 million)
WS/IR(30)
51%
51%
16%
10%
10%
0%
0%
0%
AA(30)
0%
0%
0%
0%
0%
0%
0%
0%
EC/F(30)
5%
5%
50%
56%
56%
66%
66%
66%
POURO
5%
5%
0%
0%
0%
0%
0%
0%
POU AX/AA
5%
5%
0%
0%
0%
0%
0%
0%
Regionalize/Blend
17%
17%
17%
17%
17%
17%
17%
17%
Alt. Source
17%
17%
17%
17%
17%
17%
17%
17%
Totals
100%
100%
100%
100%
100%
100%
100%
100%
Notes:
1 Water softening/iron removal includes treatment technologies such as ion exchange, oxidation/filtration, reverse osmosis, and lime softening
D-4
-------
Industrial Economics, Incorporated: January 2000 Draft
Appendix E
DETAILED OCCURRENCE AND COST RESULTS
FOR COMMUNITY WATER SYSTEMS
-------
Industrial Economics, Incorporated: January 2000 Draft
APPENDIX E
Appendix E presents the detailed occurrence and cost results for each system size category,
which are summarized in Chapters 2 and 4 of this report. The appendix contains a separate table for
each regulatory option. Each table indicates the total national annual operations and maintenance
costs, annualized capital expenditures, annual monitoring costs, and total annual costs by system size
category. The number of systems affected nationally by each regulatory option is also reported. In
addition, the tables presenting the results for the uranium MCLs contain separate estimates for
surface water and ground water systems. Each table presents the results obtained through both the
direct proportion and lognormal distribution approaches.
Exhibit E-l contains the estimates for closing the gross alpha monitoring loophole; Exhibit
E-2 presents the estimates for closing the combined radium loophole; Exhibits E-3 and E-4 contain
the estimates for changing the MCL for gross alpha and combined radium, respectively; and Exhibits
E-5 through E-7 present the estimates for creating a new uranium MCL.
E-l
-------
Industrial Economics, Incorporated: January 2000 Draft
Exhibit E-l
NATIONAL COSTS DUE TO CLOSING MONITORING LOOPHOLE FOR GROSS ALPHA
(ground water systems only)
System Size Class
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
TOTAL
Directly Proportional
Number
of
Affected
Systems
102
108
0
0
0
0
0
0
211
Annual
Capital Costs
$115,817
$ 327,806
$0
$0
SO
$0
$0
$0
$ 443,624
Annual
O&M
Costs
$235,136
$ 647,056
$0
$0
$0
$0
$0
$0
$882,192
Annual
Monitoring
Costs
$ 299,850
$ 342,500
$117,165
$171,699
$ 101,934
$90,538
$22,217
$ 11,229
$1,157,132
Total Annual
Costs
$ 650,803
$ 1,317,363
$ 117,165
$171,699
$ 101,934
$ 90,538
$22,217
$11,229
$2,482,948
Lognormally Distributed
Number
of
Affected
Systems
84
89
25
31
13
7
1
0*
250
Annual
Capital
Costs
$ 96,593
$ 277,667
$ 404,049
$1,080,659
$ 1,559,203
$ 3,986,067
$ 2,336,806
$3,981,627
$ 13.722,671
Annual O&M
Costs
$ 191,916
$ 538,345
$425,307
$ 1,149,991
$ 1,689,217
$6,129,901
$3,855,565
$ 5,627,407
$ 19.607,649
Annual
Monitoring
Costs
$ 295,072
$ 337,044
$ 125,374
$ 183,729
$ 109,075
$96,881
$ 23,774
$12,016
$ 1,182,966
Total Annual
Costs
$583,581
$ 1,153,056
$ 954,730
$2,414,380
$ 3.357,496
$ 10,212,849
$6,216.145
$9,621.050
$34,513,286
Model predicts an expected value of less than 0.5 systems affected nationally.
Notes:
1 ) Results are not adjusted for double-counting of systems out-of-compliance for both the combined radium and gross alpha loopholes.
2) Detail mav not add to total due to rounding.
E-2
-------
Industrial Economics, Incorporated: January 2000 Draft
Exhibit E-2
NATIONAL COSTS DUE TO CLOSING MONITORING LOOPHOLE FOR COMBINED RADIUM
(ground water systems only)
System Size Class
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
TOTAL
Directly Proportional
Number
of
Affected
Systems
103
109
20
24
II
5
1
0*
272
Annual
Capital Costs
$119,132
$ 346,890
$ 279,049
$ 744,502
$ 1,107,357
$2,310,303
$ 1,625,459
$2,511,998
$ 9,044,692
Annual
O&M Costs
$ 232,254
$664,221
$283,106
$ 755,544
$1,116,554
$3,249,553
$2,516,964
$3,558,135
$12,376,331
Annual
Monitoring
Costs
$42,892
$ 48,993
$ 16,945
$ 24,832
$ 14,742
$ 13,094
$3,213
$ 1,624
$ 166,333
Total
Annual
Costs
$ 394,278
$ 1,060,104
$579,100
$ 1,524,878
$ 2,238,653
$5,572,951
$4,145,636
$6,071,757
$21,587,356
Lognormally Distributed
Number
of
Affected
Systems
118
125
24
30
13
7
1
0*
317
Annual
Capital Costs
$ 136,874
$ 478,305
$ 450,407
$ 1,207,169
$ 1,692,693
$4,297,618
$2,585,268
$ 4,770,023
$ 15,618,356
Annual O&M
Costs
$269,135
$817,129
$ 489,490
$ 1,338,526
$1,953,577
$6,931,454
$ 4,498,729
$ 6,726,667
$ 23,024,706
Annual
Monitoring
Costs
$ 42,892
$ 48,993
$ 16,945
$24,832
$ 14,742
$ 13,094
$3,213
$ 1,624
$ 166,333
Total Annual
Costs
$ 448,900
$ 1,344,426
$ 956,842
$2,570,527
$3,661,011
$ 11,242,165
$7,087,211
$ 11,498,313
$ 38,809,396
* Model predicts an expected value of less than 0.5 systems affected nationally.
Notes:
1) Results are not adjusted for double-counting of systems out-of-compliance for both the combined radium and gross alpha loopholes.
2) Detail mav not add to total due to rounding.
E-3
-------
Industrial Economics, Incorporated: January 2000 Draft
Exhibit K-3
NATIONAL COSTS DUE TO CHANGING THE GROSS ALPHA MCL
(ground water systems onlv)
System Size Class
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
TOTAL
Directly Proportional
Number
of
Affected
Systems
205
217
60
73
32
16
2
. 1
606
Annual
Capital Costs
$214,527
$ 579,097
$ 837,796
$ 2,235,242
$ 3,324,653
$ 6,936,296
$4,880,167
$7,541,850
$ 26,549,628
Annual O&M
Costs
$460,811
$ 1,243,043
$ 849,979
$ 2,268,394
$ 3,352,263
$9,756,235
$7,556,758
$ 10,682,700
$36,170,183
Annual
Monitoring
Costs
$0
$0
$0
$0
$0
$0
$0
$0
$0
Total Annual
Costs
$675,338
$1,822,139
$1,687,775
$ 4,503,636
$6,676,916
$16,692,531
$ 12,436,925
$ 18,224,550
$62,719,810
Lognormally Distributed
Number
of
Affected
Systems
161
170
56
68
30
15
2
1
502
Annual
Capital
Costs
$ 184,181
$ 529,000
$ 900,246
$2,408,113
$3,474,534
$8,018,156
$ 5,207,852
$8,877,316
$ 29,599,399
Annual O&M
Costs
$ 366,908
$1,028,114
$ 947,348
$2,561,929
$ 3,764,390
$ 12,216,672
$ 8,594,268
$ 12,546,866
$ 42,026,495
Annual
Monitoring
Costs
$0
$0
$0
$0
$0
$0
$0
$0
$0
Total Annual
Costs
$551,089
$1,557,114
$ 1,847,594
$ 4,970,042
$ 7,238.924
$ 20,234,828
$ 13,802,120
$21.424,181
$71.625,893
Notes:
1 ) Results are based on full compliance with existing MCLs, after closure of the monitoring loopholes.
2) Results are not adjusted Tor double-counting of systems out-of-compliance with both the revised gross alpha and combined radium MCLs.
3) Detail mav not add to total due to rounding.
E-4
-------
Industrial Economics, Incorporated: January 2000 Draft
Exhibit E-4
NATIONAL COSTS DUE TO CHANGING THE COMBINED RADIUM MCL
(ground water svstems onlv)
System Size Class
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
TOTAL
Directly Proportional
Number
of
Affected
Systems
41
43
40
49
21
II
1
1
207
Annual
Capital Costs
$47,475
$ 136,394
$ 558,004
$ 1,488,937
$2,214,668
$ 4,620,627
$3,250,912
$ 5,023,993
$ 17,341,009
Annual O&M
Costs
$ 94,705
$ 262,389
$566,117
$1,511,032
$2,233,126
$6,499,124
$5,033,911
$7,116,265
$23,316,669
Annual
Monitoring
Costs
$0
$0
$0
$0
$0
$0
$0
$0
$0
Total Annual
Costs
$142,180
$ 398,783
$ 1,124,121
$ 2,999,969
$ 4,447,794
$11,119,750
$ 8,284,823
$ 12,140,258
$ 40,657,678
Lognormally Distributed
Number
of
Affected
Systems
61
65
28
34
15
8
1
0«
212
Annual
Capital
Costs
$68,135
$ 192,164
$465,872
$ 1,246,438
$1,784,865
$ 4,468,397
$ 2,685,497
$ 4,653,286
$ 15,564,653
Annual O&M
Costs
$138,785
$ 384,233
$494,913
$ 1,342,505
$ 1,963,659
$ 6,925,236
$4,481,476
$6,568,791
$ 22,299,598
Annual
Monitoring
Costs
$0
$0
$0
$0
$0
$0
$0
$0
$0
Total Annual
Costs
$ 206,920
$ 576,397
$ 960,785
$ 2,588.942
$3,748,524
$11,393,633
$7,166,973
$11,222,077
$37,864,251
* Model predicts an expected value of less than 0.5 systems affected nationally.
Notes:
1) Results are based on full compliance with existing MCLs, after closure of the monitoring loopholes.
2) Results are not adjusted for double-counting of systems out-of-compliance with both the revised gross alpha and combined radium MCLs.
3) Detail may not add to total due to roundine.
E-5
-------
Industrial Economics, Incorporated: January 2000 Draft
Exhibit E-5
NATIONAL COSTS DUE TO ESTABLISHING URANIUM MCL AT 20 pCi/L
System Sizt Class
Directly Proportional
Number of
Affected
Systems
Annual
Capital Costs
Annual
O&M Costs
Annual
Monitoring
Costs
Total Annual
Costs
Lognormally Distributed
Number of
Affected
Systems
Annual
Capital Costs
Annual O&M
Costs
Annual
Monitoring
Costs
Total Annual
Costs
Ground Water Systems
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
TOTAL
369
391
20
24
II
5
1
0*
821
$511,761
$ 1,588,823
$372,326
$ 960,535
$ 1,107,558
$2,311,986
$ 1,624,413
$ 2,568,428
$11,045,830
$ 787,528
$2,535,141
$ 407,045
$ 1,056,488
$1,116,245
$ 3,250,932
$2,513,659
$3,638,107
$ 15,305,144
$ 793,578
$ 906,457
$ 269,974
$ 395,632
$ 234,877
$208,618
$51,194
$ 25,874
$2,886,203
$ 2,092,866
$ 5,030,420
$1,049,345
$2,412,655
$ 2,458,679
$5,771,537
$4,189,266
$ 6,232,409
$29,237,178
324
342
83
101
44
23
2
1
921
$457,562
$ 1,441,744
$1,948,004
$5,175,360
$6,294,165
$ 12,927,409
$9,785,965
$ 19,195,466
$ 57,225,675
$ 696,933
$ 2,265,563
$ 2,555,766
$6,901,236
$ 8,329,306
$21,552,612
$18,195,916
$27,214,162
$87,711,493
$ 770,307
$ 879,877
$310,710
$ 455,328
$270,317
$ 240,097
$58,918
$ 29,779
$3,015,334
$ 1,924,803
$4,587,183
$4,814,480
$12,531,924
$ 14,893,788
$34,720.118
$ 28,0-10,799
$46,439,407
$ 147,952,502
Surface Water Systems
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
TOTAL
1
3
0
0
0
0
0
0
4
$ 1,522
$ 9,025
$0
$0
$0
$0
$0
$0
$ 10,547
$ 3,426
$ 18,524
$0
$0
$0
$0
$0
$0
$21,950
$587,313
$ 670,853
$ 244,649
$358,519
$212,844
$ 189,048
$ 46,392
$ 23,447
$ 2,333,064
$592,261
$ 698,402
$ 244,649
$358,519
$212,844
$189,048
$ 46,392
$ 23,447
$2,365,561
6
12
5
10
8
7
1
1
50
$ 6,839
$ 42,040
$ 23,998
$70,210
$ 167,300
$272,317
$ 198,281
$ 746,476
$ 1,527,461
$ 14,676
$81,976
$61,513
$204,155
$418,145
$931,440
$ 767,609
$2,604,819
$ 5,084,334
$621,781
$710,224
$257,555
$ 377,432
$ 224,072
$ 199,021
$48,839
$ 24,684
$ 2,463,608
$ 643,296
$ 834,240
$ 343,066
$651,797
$809,517
$1,402,778
$ 1,014,729
$3,375,979
$ 9,075,403
* Model predicts an expected value of less than 0.5 systems affected nationally.
Notes:
1 ) Detail may not add to total due to rounding.
E-6
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Industrial Economics, Incorporated: January 2000 Draft
Exhibit E-6
NATIONAL COSTS DUE TO ESTABLISHING URANIUM MCL AT 40 oCi/L
System Size Class
Directly Proportional
Number of
Affected
Systems
Annual
Capital Costs
Annual
O&M Costs
Annual
Monitoring
Costs
Total Annual
Costs
Lognormally Distributed
Number of
Affected
Systems
Annual
Capital Costs
Annual O&M
Costs
Annual
Monitoring
Costs
Total Annual
Costs
Ground Water Systems
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
TOTAL
144
152
0
0
0
0
0
0
296
$ 169,806
$ 472,833
$0
$0
$0
$0
$0
SO
$ 642,639
$ 284,584
$ 859,822
$0
$0
$0
$0
SO
$0
$ 1,144,406
$ 678,582
$775,104
$ 256,894
$ 376,463
$ 223,497
$ 198,5 II
$48,713
$24,621
$ 2,582,384
$1,132,971
$2,107,759
$ 256,894
$ 376,463
$ 223,497
$198,511
$48,713
$24,621
$ 4,369,429
146
155
35
42
19
10
1
1
408
$203,541
$ 634,899
$803,819
$2,129,518
$2,582,371
$ 5,995,989
$ 4,003,003
$ 7,586,253
$ 23,939,393
$312,671
$ 1,009,588
$ 1,022,947
$ 2,759,639
$ 3,328,392
$ 10,091,830
$7,341,777
$10,767,174
$36,634,017
$679,981
$ 776,703
$ 279,375
$ 409,408
$ 243,056
$215,883
$ 52,977
$ 26,775
$2,684,158
$ 1,196,193
$2,421,190
$2,106,140
$ 5,298,565
$6,153,819
$ 16,303,702
$ 11,397,757
$ 18,380,202
$63,257,568
Surface Water Systems
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
TOTAL
0
0
0
0
0
0
0
0
0
$0
$0
$0
$0
$0
$0
SO
SO
$0
$0
$0
$0
$0
$0
SO
$0
$0
$0
$ 576,529
$658,535
$ 244,484
$ 358,277
$212,700
$ 188,921
$ 46,360
$23,431
$ 2,309,238
$ 576,529
$658,535
$ 244,484
$ 358,277
$212,700
$188,921
$ 46,360
$23,431
$ 2,309,238
2
5
2
4
3
2
0*
0*
19
$ 2,638
$ 16,056
$ 8,489
$ 24,909
$ 59,256
$ 98,922
$71,001
$268,808
$ 550,078
$ 5,732
$31,741
$ 22,023
$ 73,383
$ 150,221
$ 338,246
$ 274,223
$930,555
$ 1,826,124
$594,109
$678,616
$ 249,094
$ 365,034
$216,712
$ 192,484
$47,235
$ 23,873
$2,367,156
$ 602,480
$726,413
$ 279,606
$ 463,325
$426,189
$629,651
$ 392,459
$1,223,236
$4,743,358
* Model predicts an expected value of less than 0.5 systems affected nationally.
Notes:
1) Detail may not add to total due to rounding.
E-7
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Industrial Economics, Incorporated: January 2000 Draft
Exhibit E-7
NATIONAL COSTS DUE TO ESTABLISHING URANIUM MCL AT 80 nCi/L
System Size Class
Directly Proportional
Number of
Affected
Systems
Annual
Capital Costs
Annual
O&M Costs
Annual
Monitoring
Costs
Total Annual
Costs
Lognormally Distributed
Number of
Affected
Systems
Annual
Capital Costs
Annual O&M
Costs
Annual
Monitoring
Costs
Total Annual
Costs
Ground Water Systems
25-100
101-500
501-1,000
1,001-3.300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
TOTAL
21
22
0
0
0
0
0
0
42
$21,458
$ 53,832
$0
SO
$0
$0
$0
$0
$ 75,290
$ 38,563
$110,907
$0
$0
$0
SO
$0
$0
$ 149,470
$615,566
$703,125
$ 256,690
$376,165
$ 223,320
$ 198,353
$48,675
$24,601
$ 2,446,495
$675,587
$ 867,863
$ 256,690
$376,165
$ 223,320
$ 198,353
$48,675
$24,601
$2,671,254
60
64
13
16
7
4
0*
0*
165
$82,691
$255,116
$300,169
$794,139
$ 959,737
$ 2,877,849
$ 1,481,967
$2,785,321
$ 9,536,987
$ 128,132
$410,792
$372,414
$ 1,004,150
$ 1,208,058
$ 4,985,354
$2.683,114
$ 3,944,950
$ 14,736,962
$ 635,903
$ 726,355
$265,214
$ 388,656
$ 230,736
$ 204,940
$50,291
$25,418
$2,527,514
$ 846,726
$ 1,392,262
$ 937.796
$2,186,945
$ 2,398,530
$8,068,142
$4,215,372
$ 6,755,689
$26.801,462
Surface Water Systems
25-100
101-500
501-1,000
1,001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
TOTAL
0
0
0
0
0
0
0
0
0
$0
SO
$0
$0
$0
$0
$0
$0
SO
$0
$0
$0
$0
SO
$0
$0
$0
SO
$ 576,289
$658,261
$244,391
$358,141
$212,620
$ 188,849
$ 46,343
$ 23,423
$2,308,316
$ 576,289
$658,261
$244,391
$358,141
$212,620
$188,849
$ 46,343
$ 23,423
$2,308,316
1
2
1
1
1
1
0«
0*
6
$885
$5,617
$ 2,749
$8,141
$19,185
$ 33,203
$ 23,049
$90,610
$ 183,439
$ 1.994
$11,224
$7,195
$24,182
$ 49,095
$113,335
$89,160
$315,702
$611,888
S 582.564
$ 665,429
$ 245,877
$360,319
$213.913
$ 189,998
$ 46,624
$ 23,565
$ 2,328,288
$ 585,443
$ 682.269
$255,821
$ 392,642
$282,193
$336,535
$158,834
$ 429,877
$3,123,615
* Model predicts an expected value or less than 0.5 systems affected nationally.
Notes:
1 ) Detail may not add to total due to rounding.
E-8
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Industrial Economics, Incorporated: January 2000 Draft
Appendix F
TRENDS IN COSTS AND RISK REDUCTIONS ASSOCIATED
WITH ADDITIONAL RADIUM OPTIONS
-------
Industrial Economics, Incorporated: January 2000 Drafi
Appendix F
TRENDS IN COSTS AND RISK REDUCTIONS ASSOCIATED
WITH ADDITIONAL RADIUM OPTIONS
In the text of this report, we report the results of the analysis for a single MCL option for
combined radium: limiting the contribution of radium-228 to 3 pCi/L within the total MCL of 5
pCi/L. Earlier analyses (conducted in June 1999) considered other options that placed more stringent
limits on the contribution of radium-228, including limits of 1 pCi/L, 2 pCi/L, and 2.5 pCi/L, in
addition to 3 pCi/L. In this Appendix, we present the results of those initial analyses and discuss the
implications of the overall trend in the results. Note that these results are based on outdated
assumptions and earlier versions of the cost and risk models, and hence should be approached with
caution.
The results of these analyses show that as the limit on the contribution of radium-228
decreases from 3 pCi/L to 1 pCi/L, the compliance costs for community water systems increase more
substantially than the value of avoided the cancer cases. The net benefits for all of the options are
negative, with costs that exceed benefits in all cases.
These estimates are presented to provide insights into the pattern of the incremental changes
across regulatory options. We have since made several major changes to the analytic approach to
improve the accuracy of the resulting estimates. Therefore, the estimates in this Appendix for the
MCL option limiting radium-228 to 3 pCi/L do not match the estimates presented in Chapters 2, 3,
and 4 of this report.
Exhibit F-l summarizes the costs and benefits of each option for community water systems.
The annual value of avoided cancer cases and national compliance costs are presented graphically
in Exhibit F-2 to highlight the overall trend in the results.
F-l
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Industrial Economics, Incorporated: January 2000 Draft
Exhibit F 1
PRELIMINARY ESTIMATES OF
ANNUAL COSTS AND RISK REDUCTIONS ASSOCIATED WITH COMBINED RADIUM MCL OPTIONS1
Options
Radium-228 at 1 pCi/L
Radium-228 at 2 pCi/L
Radium-228 at 2.5
pCi/L
Radium-228 at 3 pCi/L
Number of
Systems
Exceeding MCL
3,893 systems
581 systems
280 systems
199 systems
Total Cancer
Cases Avoided
(fatal cases)
4.57 cases total
(3.26 fatal)
1 .27 cases total
(0.90 fatal)
0.56 cases total
(0.40 fatal)
0.56 cases total
(0.39 fatal)
Value of Avoided
Cases
(range)1
$19.0 million
($4.7 - $36.7
million)
$5.3 million
($1.3 -$10.1
million)
$2.3 million
($0.6 - $4.5
million)
$2.3 million
($0.6 - $4.4
million)
Total Compliance
Costs
$726.4 million
$142.2 million
$7 1.0 million
$52.7 million
Net Benefits'
"-$707.4 million
-$136.9 million
- $68.7 million
-$48.1 million
Cost per Case
Avoided
(fatal and
nonfatal)
$158.9 million
per case
$112.0 million
per case
$126.8 million
per case
$94.1 million
per case
IMPORTANT CAVEAT:
These results reflect the data and assumptions used in a preliminary ( June 1999) analysis. Significant changes have been made since that time which affect the
absolute value of the estimates of costs and risks. These changes may have less of an effect, however, on the general relationship observed between costs and risk
reductions across regulatory options.
Notes:
1 . Costs and risk reductions are compared to a full compliance baseline (i.e., occurrence data are adjusted to eliminate illegal and legal noncompliance).
2. Best estimate (in 1997 dollars) is $5.8 million per fatal case and S 0.099 million per nonfatal case; range is $1.4 million - $1 1.2 million per fatal case and $0.088 -
$0.1 10 million per nonfatal case. Value for fatalities based on estimates of value of statistical life; value for nonfatal cases is estimate of average medical costs
of illness.
3. Net benefits (best estimate of value of avoided cases minus compliance costs) are negative in all cases; i.e., costs exceed benefits.
F-2
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Industrial Economics, Incorporated: January 2000 Draft
Exhibit F-2
ANNUAL COSTS AND RISK REDUCTIONS ASSOCIATED WITH EACH
COMBINED RADIUM MCL OPTION
800
700 ,
600
£ 500 .
£
Z 400 .
e
i 300
5 200
100 .
0
I
. \
\
\
\
\
\
4 '
; f Total Compliance Costs
i + Value of Avoided Cases
0 0.5 1 1.5 2 2.5 3 3.5
Limit of Contribution ofRa-228
(pci/L)
Note:
1. See discussion regarding limitations in the analysis on previous pages.
F-3
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