EPA-815-Z-99-002
Health Risk Reduction and Cost Analysis for
Radon in Drinking Water:
Notice, Request for Comments, and
Announcement of Stakeholder Meeting
Pre-Publication Copy of Federal Register Notice
for Review and Public Comment
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Disclaimer
The acting Assistant Administrator for the Office of Water signed the following
document on February 5, 1999 and it is being submitted for publication in the Federal Register.
This document is also available on EPA Office of Ground Water and Drinking Water's web page
on radon at: http://www.epa.gov/safewater/standard/pp/radonpp.html. While EPA has taken steps
to ensure the accuracy of this version of the document, it is not the official version of the
document. Please refer to the official version in a forthcoming Federal Register publication.
You can also access the Federal Register on the Internet at GPO's web site:
http://www.access.gpo.gov/su_docs/aces/acesl40.html. Once the official Federal Register
version of the document is published, EPA's web page will have a link to the GPO site.
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U.S. ENVIRONMENTAL PROTECTION AGENCY
Radon in Drinking Water Health Risk Reduction and Cost Analysis
AGENCY: Environmental Protection Agency
ACTION: Notice and Request for Public Comments and Announcement of Stakeholder Meeting
SUMMARY: The Safe Drinking Water Act (SDWA), as amended in 1996, requires the U.S.
Environmental Protection Agency (EPA) to publish a health risk reduction and cost analysis
(HRRCA) for radon in drinking water for public comment. The purpose of this notice is to
provide the public with the HRRCA for radon and to request comments on the .document. As
required by SDWA, EPA will publish a response to all significant comments to the HRRCA in
the preamble to the proposed NPDWR for radon, due in August, 1999.
The goal of the HRRCA is to provide a neutral and factual analysis of the costs, benefits,
and other impacts of controlling radon levels in drinking water. The HRRCA is intended to
support future decision making during development of the radon NPDWR. The HRRCA
evaluates radon levels in drinking water of 100, 300, 500, 700,1000, 2000, and 4000 pCi/L. The
HRRCA also presents information on the costs and benefits of implementing multimedia
mitigation (MMM) programs to reduce the risks of radon exposure in indoor air. The SDWA, as
amended, provides for development of an Alternative Maximum Contaminant Level (AMCL),
which public systems may comply with if their State has an EPA approved MMM program to
reduce radon in indoor air. The concept behind the AMCL and MMM option is to reduce radon
health risks by addressing the larger source of exposure (air levels in homes) compared to
drinking water. If a State chooses to employ a MMM program to reduce radon risk, it would
implement a State program to reduce indoor air levels and require public water systems to
control water radon levels to the AMCL. If a State does not choose a MMM program option, a
public water system may propose a MMM program for EPA approval. Today's notice does not
include any decisions regarding the choice of a Maximum Contaminant Level (MCL) for radon
in drinking water. Today's notice also announces a stakeholder meeting on the HRRCA and
framework for the MMM program.
DATES: The Agency must receive comments on the HRRCA on or before [45 DAYS AFTER
PUBLICATION IN THE FEDERAL REGISTER]. EPA will hold a one day public meeting
on March 16,1999.
ADDRESSES: Send written comments on HRRCA to the Comment Clerk, docket number W-
98-30, Water Docket (MC4101), USEPA, 401 M St., SW, Washington, DC 20460. Please
submit an original and three copies of your comments and enclosures (including references).
Comments must be received or postmarked by midnight [45 DAYS AFTER PUBLICATION
IN THE FEDERAL REGISTER].
Commenters who want EPA to acknowledge receipt of their comments should enclose a
self-addressed, stamped envelope. No facsimiles (faxes) will be accepted. Comments may also
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be submitted electronically to ow-docket@epa.gov. Electronic comments must be submitted as
an ASCII, WP6.1, or WPS file avoiding the use of special characters and any form of encryption.
Electronic comments must be identified by the docket number W-98-30. Comments and data
will also be accepted on disks in WP6.1, WPS, or ASCII file format. Electronic comments on
this notice may be filed online at many Federal Depository Libraries.
The record for this notice has been established under docket number W-98-30, and
includes supporting documentation as well as printed, paper versions of electronic comments.
The full record is available for inspection from 9 a.m. to 4 p.m. EST Monday through Friday,
excluding legal holidays at the Water Docket, Room EB57, USEPA Headquarters, 401 M St.,
SW, Washington, DC 20460. For access to docket materials, please call 202-260-3027 to
schedule an appointment.
The stakeholder meeting on the HRRCA and multimedia mitigation framework will be
held on Tuesday, March 16,1999 from 9:00 a.m. to 5:30 p.m EST at the offices of at RESOLVE,
Inc., 1255 23rd Street, N.W,. Suite 275, Washington, DC 20037. Check-in will begin at 8:30
a.m.
FOR FURTHER INFORMATION CONTACT: For general information, please contact the
EPA Safe Drinking Water Hotline at 1-800-426-4791 or 703-285-1093 between 9 a.m. and 5:30
p.m. EST. (For information on radon in indoor air, contact the National Safety Council's
National Radon Hotline at 1-800-SOS-RADON). The HRRCA, including the appendices, can
also be accessed on the internet at http://www.epa.gov/safewater/standard/pp/radonpp/html. For
specific information and technical inquiries, contact Michael Osinski at 202-260-6252 or
osinski.michael@epa.gov.
For general information on meeting logistics, please contact Sheri Jobe at RESOLVE,
Inc., at 202-965-6382 or Email: sjobe@resolv.org.
SUPPLEMENTARY INFORMATION: The purpose of the March 16, 1999 stakeholder
meeting is to cover the following key issues, including: (1) discussion of the Health Risk
Reduction and Cost Analysis published in this notice; and (2) present information and discuss
issues related to status of development of a framework for multimedia mitigation programs. This
upcoming meeting is the fifth of a series of stakeholders meetings on the NPDWR for radon,
intended to seek input from State and Tribal drinking water and radon programs, the regulated
community (public water systems), public health and safety organizations, environmental and
public interest groups, and other stakeholders. EPA encourages the full participation of
stakeholders throughout this process.
To register for the meeting, please contact Sheri Jobe at RESOLVE, Inc.,
1255 23rd Street, N.W,. Suite 275, Washington, DC 20037, Phone: 202-965-6382,
Fax: 202-338-1264, Email: siobe@resolv.org. Please provide your name, affiliation/organization,
address, phone, fax and email if you would like to be on the mailing list to receive further
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information about the meeting (including agenda and meeting summary). A limited number of tele-
conference lines will be available. Please indicate whether you would like to participate by phone.
Those registered for the meeting by February 26, 1999 will receive an agenda, logistics sheet, and
other information prior to the meeting.
Date:
Dana D. Minerva,
Acting Assistant Administrator, Office of Water
Environmental Protection Agency
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RADON IN DRINKING WATER HEALTH RISK REDUCTION AND COST ANALYSIS
Table of Contents
1. EXECUTIVE SUMMARY
2. INTRODUCTION
2.1 Background
2.2 Regulatory History
2.3 Safe Drinking Water Act Amendments of 1996
2.4 Specific Requirements for the Health Risk Reduction and Cost Analysis
2.5 Radon Levels Evaluated
2.6 Document Structure
3. HEALTH EFFECTS FROM RADON EXPOSURE
3.1 Radon Occurrence and Exposure Pathways
3.1.1 Occurrence
3.1.2 Exposure Pathways
3.2 Nature of Health Impacts
3.3 Impacts on Sensitive Subpopulations
3.4 Risk Reduction Model for Radon in Drinking Water
3.5 Risks from Existing Radon Exposures
3.6 Potential for Risk Reductions Associated with Removal of Co-Occurring
Contaminants
3.7 Potential for Risk Increases from Other Contaminants Associated with Radon
Removal
3.8 Risk for Ever-Smokers and Never-Smokers
4. BENEFITS OF REDUCED RADON EXPOSURE
4.1 Nature of Regulatory Impacts
4.1.1 Quantifiable Benefits
4.1.2 Non-Quantifiable Benefits
4.2 Monetization of Benefits
4.2.1 Estimation of Fatal and Non-Fatal Cancer Risk Reduction
4.2.2 Value of Statistical Life for Fatal Cancers Avoided
4.2.3 Costs of Illness and Lost Time for Non-Fatal Cancers
4.2.4 Willingness to Pay to Avoid Non-Fatal Cancers
4.3 Treatment of Monetized Benefits Over Time
5. COSTS OF RADON TREATMENT MEASURES
5.1 Drinking Water Treatment Technologies and Costs
5.1.1 Aeration
5.1.2 Granular Activated Carbon (GAC)
5.1.3 Storage
5.1.4 Regionalization
5.1.5 Radon Removal Efficiencies
5.1.6 Pre-Treatment to Reduce Iron and Manganese Levels
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5.1.7 Post-Treatment — Disinfection
5.2 Monitoring Costs
5.3 Water Treatment Technologies Currently In Use
5.4 Cost of Technologies as a Function of Flow Rates and Radon Removal Efficiency
5.5 Choice of Treatment Responses
5.6 Cost Estimation
5.6.1 Site and System Costs
5.6.2 Aggregate National Costs
5.6.3 Costs to Community Water Systems
5.6.4 Costs to Consumers/Households
5.6.5 Costs to Non-Transient Non-Community Systems
5.7 Application of Radon Related Costs to Other Rules
6. RESULTS: COSTS AND BENEFITS OF REDUCING RADON IN DRINKING WATER
6.1 Overview of Analytical Approach
6.2 Health Risk Reduction and Monetized Health Benefits
6.3 Costs of Radon Mitigation
6.4 Incremental Costs and Benefits of Radon Removal
6.5 Costs to Community Water Systems
6.6 Costs and Impacts to Households
6.7 Summary of Cost and Benefit Analysis
6.8 Sensitivities and Uncertainties
6.8.1 Uncertainties in Risk Reduction and Health Benefits Calculations
6.8.2 Uncertainty in Cost and Impact Calculations
7. IMPLEMENTATION SCENARIOS - MULTIMEDIA MITIGATION PROGRAMS
7.1 Multimedia Mitigation Programs
7.2 Implementation Scenarios Evaluated
7.3 Multimedia Mitigation Cost and Benefit Assumptions
7.4 Annual Costs and Benefits of Multimedia Mitigation Program Implementation
7.6 Sensitivities and Uncertainties
Appendix A. Equations and Parameter Values Used in the Assessment of Risks and Risk
Reduction Benefits
Appendix B. Cost Curves for Radon Reduction and Disinfection Technologies
Appendix C. Flow Estimation Equations for Public and Private Water Systems
Appendix D. Summary Cost Tables
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List of Tables and Figures
Table 3 -1. Radon Distributions by Region
Table 3-2. Radon Distribution in Public Water Systems
Table 3-3. Population Exposed Above Various Radon Levels By System Size
Table 3-4. Estimated Radon Unit Lifetime Fatal Cancer Risks in Community Water Systems
Table 3-5. Radon Treatment Assumptions to Calculate Residual Fatal Cancer Risks
Table 3-6. Annual Fatal Cancer Risks for Exposures to Radon from Community Water
Systems
Table 3-7. Radon Risk Reductions Across Various Effluent Levels and Percent Removals
Table 3-8. Radon Risk Reduction from Treatment Compared to DBP Risks
Table 3-9. Annual Lung Cancer Death Risks Estimates from Radon Progeny for Ever-
Smokers, Never-Smokers, and the General Population
Table 4-1. Proportion of Fatal Cancers by Exposure Pathway and Estimated Mortality
Table 4-2. Estimated Medical Care and Lost-Time Costs Per Case for Survivors of Lung
Cancer
Table 4-3. Estimated Medical Care and Lost-time Costs Per Case for Survivors of Stomach
Cancer
Table 5-1. Unit Treatment Costs by Removal Efficiency and System Size
Table 5-2. Estimated Proportions of Ground Water Systems With Water Treatment
Technologies Already in Place
Table 5-3. Decision Matrix For Selection of Treatment Technology Options
Table 5-4. Number of Sites per Ground Water System by System Size
Table 6-1. Risk Reduction and Residual Cancer Risk from Reducing Radon in Drinking
Water
Table 6-2. Estimated Monetized Health Benefits from Reducing Radon in Drinking Water
Table 6-3. Risk Reduction and Monetized Benefits Estimates For Ever-Smokers
Table 6-4. Risk Reduction and Monetized Benefits Estimates For Never-Smokers
Table 6-5. Estimated Annualized National Costs of Reducing Radon Exposures
Table 6-6. Capital and O&M Costs of Mitigating Radon in Drinking Water
Table 6-7. Estimates of the Annual Incremental Costs and Benefits of Reducing Radon in
Drinking Water
Table 6-8. Number of Community Water Systems Exceeding Various Radon Levels
Table 6-9. Average Annual Cost Per System
Table 6-10. Annual Costs per Household for Community Water Systems
Table 6-11. Per Household Impact by Community Water System as a Percentage of Median
Household Income
Table 6-12. Estimated National Annual Costs and Benefits of Reducing Radon Exposures -
Central Tendency Estimate
Table 6-13. Total Annual Costs and Fatal Cancers Avoided by System Size
Table 6-14. Annual Monetized Health Benefits by System Size
Table 7-1. Central Tendency Estimates of Annualized Costs and Benefits of Reducing Radon
Exposures with 50% of States Selecting the MMM/AMCL Option
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Table 7-2. Central Tendency Estimates of Annualized Costs and Benefits of Reducing Radon
Exposures with 100% of States Selecting the MMM/AMCL Option
Figure 3-1. General Patterns of Radon Occurrence in Ground Water
Figure 3-2. EPA Map of Radon Zones in Indoor Air
Figure 6-1. Sensitivity Analysis of Water Mitigation Costs
Figure 7-1 Sensitivity Analysis to Changes in MMM Cost Estimates
Abbreviations Used in This Document
AF: Average Flow
AMCL: Alternative Maximum Contaminant Level
AWWA: American Water Works Association
BAT: Best Available Technology
CWS: Community Water System
DA: Diffused-Bubble Aeration
DBP: Disinfection By-Products
DF: Design Flow
GAC: Granular Activated Carbon
EPA: US Environmental Protection Agency
FACA: Federal Advisory Committee Act
HRRCA: Health Risk Reduction and Cost Analysis
MCL: Maximum Contaminant Level
MCLG: Maximum Contaminant Level Goal
MMM: Multimedia Mitigation program
MSBA: Multi-Stage Diffused Bubble Aeration
NAS: National Academy of Sciences
NDWAC: National Drinking Water Advisory Council
NIRS: National Inorganics and Radionuclides Survey
NPDWR: National Primary Drinking Water Regulation
NTNCWS: Non-Transient Non-Community Water System
OGWDW: Office of Ground Water and Drinking Water
O&M: Operation and Maintenance
OMB: Office of Management and Budget
pCi/1: Picocurie Per Liter
POE GAC: Point-of-Entry Granular Activated Carbon
PTA: Packed Tower Aeration
RIA: Regulatory Impact Analysis
SAB: Science Advisory Board
SDWA: Safe Drinking Water Act, as amended in 1986 and 1996
SDWIS: Safe Drinking Water Inventory System
THM: Trihalomethane
VSL: Value of a Statistical Life
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WTP: Willingness To Pay
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1. EXECUTIVE SUMMARY
This document constitutes the Health Risk Reduction and Cost Analysis (HRRCA) in
support of development of a National Primary Drinking Water Regulation (NPDWR) for radon
in drinking water, as required by Section 1412(b)(13) of the 1996 Amendments to the Safe
Drinking Water Act (SOWA). The goal of the HRRCA is to provide a neutral and fact-based
analysis of the costs, benefits, and other impacts of controlling radon levels in drinking water to
support future decision making during development of the radon NPDWR. The document
addresses the various requirements for the analysis of benefits, costs, and other elements
specified by Section 1412(b)(13) of the SDWA, as amended.
This is the first time the Environmental Protection Agency (EPA) has prepared a HRRCA
under the SDWA, as amended. As such, the EPA is very interested in seeking comment on the
techniques, assumptions, and data inputs upon which the analysis is based. The Agency
recognizes that there may be other methods of conducting the analysis and presenting the data
required for this HRRCA, and encourages meaningful input from all stakeholders during the
public comment period. Therefore, the specific analysis and findings presented here are intended
as an initial effort to frame an analysis that can support development of the NPDWR. Since the
HRRCA is a cost-benefit tool to analyze an array of radon levels during development of the
NPDWR, many of the issues to be addressed in the regulatory development process (e.g. the
selection of a Maximum Contaminant Level (MCL), Best Available Technology (BAT), and
monitoring framework) are not analyzed here, but will be presented in the proposed rule.
The HRRCA evaluates radon levels in ground water supplies of 100, 300, 500, 700, 1000,
2000, and 4000 pCi/1. The HRRCA also presents information on the costs and benefits of
implementing multimedia mitigation (MMM) programs. The scenarios evaluated are described
in detail in Section 2.5. This executive summary presents a background on the radon in drinking
water problem, followed by a summary of findings arranged according to each provision for
HRRCAs as specified by the SDWA, as amended.
Background: Radon Health Risks, Occurrence, and Regulatory History
Radon is a naturally occurring volatile gas formed from the normal radioactive decay of
uranium. It is colorless, odorless, tasteless, chemically inert, and radioactive. Uranium is present
in small amounts in most rocks and soil, where it decays to other products including radium, then
to radon. Some of the radon moves through air or water-filled pores in the soil to the soil surface
and enters the air, and can enter buildings through cracks and other holes in the foundation.
Some radon remains below the surface and dissolves in ground water (water that collects and
flows under the ground's surface). Due to their very long half-life (the time required for half of a
given amount of a radionuclide to decay), uranium and radium persist in rock and soil.
Exposure to radon and its progeny is believed to be associated with increased risks of
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several kinds of cancer. When radon or its progeny are inhaled, lung cancer accounts for most of
the total incremental cancer risk. Ingestion of radon in water is suspected of being associated
with increased risk of tumors of several internal organs, primarily the stomach. As required by
the SDWA, EPA arranged for the National Academy of Sciences (NAS) to assess the health risks
of radon in drinking water. The NAS released the "Report on the Risks of Radon in Drinking
Water,"(NAS Report) in September 1998 (NAS 1998B). The NAS Report represents a
comprehensive assessment of scientific data gathered to date on radon in drinking water. The
report, in general, confirms earlier EPA scientific conclusions and analyses of radon in drinking
water(USEPA,1994C).
NAS recently estimated individual lifetime unit fatal cancer risks associated with
exposure to radon from domestic water use for ingestion and inhalation pathways (Table 3-4).
The results show that inhalation of radon progeny accounts for most (approximately 89 percent)
of the individual risk associated with domestic water use, with almost all of the remainder (11
percent) resulting from directly ingesting radon in drinking water. Inhalation of radon progeny is
associated primarily with increased risk of lung cancer, while ingestion exposure is associated
primarily with elevated risk of stomach cancer.
The NAS Report confirmed that indoor air contamination arising from soil gas typically
account for the bulk of total individual risk due to radon exposure. Usually, most radon gas
enters indoor air by diffusion from soils through basement walls or foundation cracks or
openings. Radon in domestic water generally contributes a small proportion of the total radon in
indoor air.
The NAS Report is one of the most important inputs used by EPA in the HRRCA. EPA
has used the NAS's assessment of the cancer risks from radon in drinking water to estimate both
the health risks posed by existing levels of radon in drinking water and also the cancer deaths
prevented by reducing radon levels.
In updating key analyses and developing the framework for the cost-benefit analysis
presented in the HRRCA, EPA has consulted with a broad range of stakeholders and technical
experts. Participants in a series of stakeholder meetings held in 1997 and 1998 included
representatives of public water systems, State drinking water and indoor air programs, Tribal
water utilities and governments, environmental and public health groups, and other federal
agencies.
The HRRCA builds on several technical components, including estimates of radon
occurrence in drinking water, analytical methods for detecting and measuring radon levels, and
treatment technologies. Extensive analyses of these issues were undertaken by the Agency in the
course of previous rulemaking efforts for radon and other radionuclides. Using data provided by
stakeholders, and from published literature, the EPA has updated these technical analyses to take
into account the best currently available information and to respond to comments on the 1991
proposed NPDWR for radon. As required by the 1996 Safe Drinking Water Act (SDWA), EPA
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has withdrawn the proposed NPDWR for radon (US EPA 1997B) and will propose a new
regulation by August, 1999. The HRRCA does not include any decisions regarding the choice of
a Maximum Contaminant Level (MCL) for radon in drinking water.
The analysis presented in this HRRCA uses updated estimates of the number of active
public drinking water systems obtained from EPA's Safe Drinking Water Information System
(SDWIS). Treatment costs for the removal of radon from drinking water have also been updated.
The HRRCA follows current EPA policies with regard to the methods and assumptions used in
cost and benefit assessment.
As part of the regulatory development process, EPA has updated and refined its analysis
of radon occurrence patterns in ground water supplies in the United States (US EPA 1998L).
This new analysis incorporates information from the EPA's 1985 National Inorganic and
Radionuclides Survey (NIRS) of 1000 community ground water systems throughout the United
States, along with supplemental data provided by the States, water utilities, and academic
research. The new study also addressed a number of issues raised by public comments in the
previous occurrence analysis that accompanied the 1991 proposed NPDWR, including
characterization of regional and temporal variability in radon levels, and the impact of sampling
point for monitoring compliance.
In general, radon levels in ground water in the United States have been found to be the
highest in New England and the Appalachian uplands of the Middle Atlantic and Southeastern
states (Figure 3-1). There are also isolated areas in the Rocky Mountains, California, Texas, and
the upper Midwest where radon levels in ground water tend to be higher than theUnited States
average. The lowest ground water radon levels tend to be found in the Mississippi Valley, lower
Midwest, and Plains states. When comparing radon levels in ground water to radon levels in
indoor air at the State level, the distribution of radon concentrations in indoor air (Figure 3-2) do
not always mirror distributions of radon in ground water.
In addition, the 1996 Amendments to the SDWA introduce two new elements into the
radon in drinking water rule: (1) an Alternative Maximum Contaminant Level (AMCL) and (2)
multimedia radon mitigation (MMM) programs. The SDWA, as amended, provides for
development of an AMCL, which public water systems may comply with if their State has an
EPA approved MMM program to reduce radon in indoor air. The NAS Report estimated that the
AMCL would be about 4,000 pCi/L, based on SDWA requirements. The concept behind the
AMCL and MMM option is to reduce radon health risks by addressing the larger source of
exposure (air levels in homes) compared to drinking water. If a State chooses to employ a MMM
program to reduce radon risk, it would implement a State program to reduce indoor air levels and
require public water systems to control radon levels in drinking water to the AMCL. If a State
does not choose a MMM program option, a public water system may propose a MMM program
for EPA approval.
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Summary of Findings
Quantifiable and Non-Quantifiable Costs
The capital and operating and maintenance (O&M) costs of mitigating radon in
Community Water Systems (CWSs) were estimated for each of the radon levels evaluated. The
costs of reducing radon in ground water to specific target levels were calculated using the cost
curves discussed in Section 5.4 and the matrix of treatment options presented in Section 5.5. For
each radon level and system size stratum, the number of systems that need to reduce radon levels
by up to 50 percent, 80 percent and 99 percent were calculated. Then, the cost curves for the
distributions of technologies dictated by the treatment matrix were applied to the appropriate
proportions of the systems. Capital and O&M costs were then calculated for each system, based
on typical estimated design and average flow rates. These flow rates were calculated on
spreadsheets using equations from EPA's Safe Drinking Water Suite Model (US EPA 1998N).
The equations and parameter values relating system size to flow rates are presented in Appendix
C. The technologies addressed in the cost estimation included a number of aeration and granular
activated carbon (GAC) technologies described in Section 5.1, as well as storage, regionalization,
and disinfection as a post-treatment. To estimate costs, water systems were assumed, with a few
exceptions, to select the technology that could reduce radon to the selected target level at the
lowest cost. CWSs were also assumed to treat separately at every source from which water was
obtained and delivered into the distribution system.
The costs of reducing radon to various levels are summarized in Table 6-5, which shows
that, as expected, aggregate radon mitigation costs increase with decreasing radon levels. The
cost ranges presented in the table represent plausible upper and lower bounds of 50 percent above
to 50 percent below the central tendency estimates. For CWSs, the costs per system do not vary
substantially across the different radon levels evaluated. This is because the menu of mitigation
technologies for systems with various influent radon levels remains relatively constant.
Quantifiable and Non-Quantifiable Health Benefits
The quantifiable health benefits of reducing radon exposures in drinking water are
attributable to the reduced incidence of fatal and non-fatal cancers, primarily of the lung and
stomach. Table 6-1 shows the health risk reductions (number of fatal and non-fatal cancers
avoided) and the residual health risk (number of remaining cancer cases) at various radon in
water levels. Since preparing the prepublication edition of the NAS Report, the NAS has
reviewed and slightly revised their unit risk estimates. EPA uses these updated unit risk
estimates in calculating the baseline risks, health risk reductions, and residual risks. Under
baseline assumptions (no control of radon exposure), approximately 160 fatal cancers and 9.2
non-fatal cancers per year are associated with radon exposures through CWSs. At a radon level
of 4,000 pCi/1, approximately 2.2 fatal cancers and 0.1 non-fatal cancers per year are prevented.
At the lowest level evaluated (100 pCi/1), approximately 115 fatal and 6.6 non-fatal cancers per
year would be prevented.
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The Agency has developed monetized estimates of the health benefits associated with the
risk reductions from radon exposures. The SDWA, as amended, requires that a cost-benefit
analysis be conducted for each NPDWR, and places a high priority on better analysis to support
rulemaking. The Agency is interested in refining its approach to both the cost and benefit
analysis, and in particular recognizes that there are different approaches to monetizing health
benefits. In the past, the Agency has presented benefits as cost per life saved, as in Table 6-5.
An alternative approach presented here for consideration as one measure of potential benefits is
the monetary value of a statistical life (VSL) applied to each fatal cancer avoided. Since this
approach is relatively new to the development of NPDWRs, EPA is interested in comments on
these alternative approaches to valuing benefits, and will have to weigh the value of these
approaches for future use.
Estimating the VSL involves inferring individuals' implicit tradeoffs between small
changes hi mortality risk and monetary compensation. In the HRRCA, a central tendency
estimate of $5.8 million (1997$) is used in the monetary benefits calculations, with low- and
high-end values of $700,000 (1997$) and $16.3 million (1997$), respectively, used for the
purposes of sensitivity analysis. These figures span the range of VSL estimates from 26 studies
reviewed in EPA's recent draft guidance on benefits assessment (US EPA 1998E), which is
currently under review by the Agency's Science Advisory Board (SAB) and the Office of
Management and Budget (OMB).
It is important to recognize the limitations of existing VSL estimates and to consider
whether factors such as differences in the demographic characteristics of the populations and
differences hi the nature of the risks being valued have a significant impact on the value of
mortality risk reduction benefits. Also, medical care or lost-time costs are not separately
included in the benefits estimate for fatal cancers, since it is assumed that these costs are captured
in the VSL for fatal cancers.
For non-fatal cancers, willingness to pay (WTP) data to avoid chronic bronchitis is used
as a surrogate to estimate the WTP to avoid non-fatal lung and stomach cancers. The use of such
WTP estimates is supported in the SDWA, as amended, at Section 1412(b)(3)(C)(iii): "The
Administrator may identify valid approaches for the measurement and valuation of benefits under
this subparagraph, including approaches to identify consumer willingness to pay for reductions in
health risks from drinking water contaminants."
A WTP central tendency estimate of $536,000 is used to monetize the benefits of
avoiding non-fatal cancers (Viscusi et al. 1991), with a range between $169,000 and $1.05
million (1997$). The combined fatal and non-fatal health benefits are summarized in Table 6-2.
The annual health benefits range from $13 million for a radon level of 4000 pCi/1 to $673 million
at 100 pCi/1. The ranges in the last column of Table 6-2 illustrate how benefits vary when the
upper and lower bound estimates of the VSL and WTP measures are used.
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Reductions in radon exposures might also be associated with non-quantifiable benefits.
EPA has identified several potential non-quantifiable benefits associated with regulating radon in
drinking water. These benefits may include any peace of mind benefits specific to reduction of
radon risks that may not be adequately captured in the VSL estimate. In addition, treating radon
in drinking water with aeration oxidizes arsenic into a less soluble form that is easier to remove
with conventional removal technologies. In terms of reducing radon exposures in indoor air, it
has also been suggested that provision of information to households on the risks of radon in
indoor air and available options to reduce exposure is a non-quantifiable benefit that can be
attributed to some components of a MMM program. Providing such information might allow
households to make informed choices about the appropriate level of risk reduction given their
specific circumstances and concerns. These potential benefits are difficult to quantify because of
the uncertainty surrounding their estimation. However, they are likely to be somewhat less
significant relative to the monetized benefits estimates.
Incremental Costs and Benefits of Radon Removal
Table 6-7 summarizes the central tendency and the upper and lower bound estimates of
the incremental costs and benefits of radon exposure reduction. Both the annual incremental
costs and benefits increase as the radon level decreases from 4000 pCi/1 down to 100 pCi/1.
Incremental costs and benefits are within 10 percent of each other at radon levels of 1000, 700,
and 500 pCi/1. The table also illustrates the wide ranges of potential incremental costs and
benefits due to the uncertainty inherent in the estimates. There is substantial overlap between the
incremental costs and benefits at each radon level.
Impacts on Households
The cost impact of reducing radon in drinking water at the household level was also
assessed. As expected, costs per household increase as system size decreases (Table 6-10). Costs
to households are higher for households served by smaller systems than larger systems for two
reasons. First, smaller systems serve far fewer households than larger systems and,
consequently, each household must bear a greater percentage share of the capital and O&M
costs. Second, smaller systems tend to have higher influent radon concentrations that, on a per-
capita or per-household basis, require more expensive treatment methods (e.g., one that has an 85
percent removal efficiency rather than 50 percent) to achieve the applicable radon level.
Another significant finding is that, like the per system costs, costs per household (which
are a function of per system costs) are relatively constant across different radon levels within
each system size category. For example, there is less than one dollar per year variation in
household costs, regardless of the radon level being considered for households served by large
public or private systems (between $6 and $7 annually), by medium public or private systems
(between $10 and $11), and by small public or private systems (between $19 and $20 annually).
Similarly, for very small systems (501-3300 people), the cost per household is consistently about
$34 annually for public systems and about $40 annually for private systems, varying little with
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the target radon level. Only for very very small systems is there a noticeable variation in
household costs across radon levels. The range for per household costs for public CWSs serving
25-500 people is $87 per year (at 4,000 pCi/1) to $135 per year (at 100 pCi/1). The corresponding
range for private CWSs is $139 to $238 per year. For households served by the smallest public
systems (25-100 people) the range of cost per household ranges from $292 per year at 4000 pCi/1
to $398 per year at 100 pCi/1. For private systems, the range is $364 per year to $489 per year,
respectively.
Summary of Annual Costs and Benefits
Table 6-12 reveals that at a radon level of 4000pCi/l (equivalent to the AMCL estimated
in the NAS Report), annual costs are approximately twice the annual monetized benefits. For
radon levels of lOOOpCi/1 to 300 pCi/1, the central tendency estimates of annual costs are above
the central tendency estimates of the monetized benefits, although they are within 10 percent of
each other. However, as shown in Tables 6-2 and 6-5, due to the uncertainty in the cost and
benefit estimates, there is a very broad possible range of potential costs and benefits that overlap
across all of the radon levels evaluated.
Benefits from the Reduction of Co-Occurring Contaminants
The occurrence patterns of other industrial pollutants are difficult to clearly define at the
national level relative to a naturally occurring contaminant such as radon. Similarly, the
Agency's re-evaluation of radon occurrence has revealed that the geographic patterns of radon
occurrence are not significantly correlated with other naturally occurring inorganic contaminants
that may pose health risks. Thus, it is not likely that a clear relationship exists between the need
to install radon treatment technologies and treatments to remove other contaminants. On the
other hand, technologies used to reduce radon levels in drinking water have the potential to
reduce concentrations of other pollutants as well. Aeration technologies will also remove
volatile organic contaminants from contaminated ground water. Similarly, granular activated
.carbon (GAC) treatment for radon removal effectively reduces the concentrations of organic
(both volatile and nonvolatile) chemicals and some inorganic contaminants. Aeration also tends
to oxidize dissolved arsenic (a known carcinogen) to a less soluble form that is more easily
removed from water. The frequency and extent that radon treatment would also reduce risks
from other contaminants has not been quantitatively evaluated.
Impacts on Sensitive Subpopulations
The SDWA, as amended, includes specific provisions in Section 1412(b)(3)(C)(i)(V) to
assess the effects of the contaminant on the general population and on groups within the general
population such as children, pregnant women, the elderly, individuals with a history of serious
illness, or other subpopulations that are identified as likely to be at greater risk of adverse health
effects due to exposure to contaminants in drinking water than the general population. The NAS
Report concluded that there is insufficient scientific information to permit separate cancer risk
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estimates for potential subpopulations such as pregnant women, the elderly, children, and
seriously ill persons. The NAS Report did note, however, that according to the NAS model for
the cancer risk from ingested radon, which accounts for 11% of the total fatal cancer risk from
radon in drinking water, approximately 30% of the fatal lifetime cancer risk is attributed to
exposure between ages 0 to 10.
The NAS Report identified smokers as the only group that is more susceptible to
inhalation exposure to radon progeny (NAS 1998 A, 1998B). Inhalation of cigarette smoke and
radon progeny result in a greater increased risk than if the two exposures act independently to
induce lung cancer. NAS estimates that "ever smokers" (more than 100 cigarettes over a
lifetime) may be more than five times as sensitive to radon progeny as "never smokers" (less than
100 cigarettes over a lifetime). Using current smoking prevalence data, EPA's preliminary
estimate for the purposes of the HRRCA is that approximately 85 percent of the cases of radon-
induced cancer will occur among current and former smokers. This population of current and
former smokers, which consists of 58 percent of the male and 42 percent of the female
population (US EPA 1999 A), will also experience the bulk of the risk reduction from radon
exposure reduction in drinking water supplies.
Risk Increases from Other Contaminants Associated With Radon Exposure Reduction
As discussed in Section 5.1, the need to install radon treatment technologies may require
some systems that currently do not disinfect to do so. Case studies (US EPA 199D) of twenty-
nine small to medium water systems that installed treatment (24 aeration, 5 GAC) to remove
radon from drinking water revealed only two systems that reported adding disinfection (both
aeration) with radon treatment (the systems either had disinfection already in place or did not add
it). In practice, the tendency to add disinfection may be much more significant than these case
studies indicate. EPA also realizes that the addition of chlorination for disinfection may result in
risk-risk tradeoffs, since, for example, the disinfection technology reduces potential for infectious
disease risk, but at the same time can result in increased exposures to disinfection by-products
(DBFs). This risk-risk trade-off is addressed by the recently promulgated Disinfectants and
Disinfection By-Products NPDWR (US EPA 19981). This rule identified MCLs for the major
DBPs, which all CWSs and NTNCWSs must comply. These MCLs set a risk ceiling from DBFs
that water systems adding disinfection in conjunction with treatment for radon removal could
face. The formation of DBPs is proportional to the concentration of organic precursor
contaminants, which tend to be much lower in ground water than in surface water.
The NAS Report addressed several important potential risk-risk tradeoffs associated with
reducing radon levels in drinking water, including the trade-off between risk reduction from
radon treatment that includes post-disinfection with the increased potential for DBF formation
(NAS 1998B). The report concluded that, based upon median and average total trihalomethane
(THM) levels taken from EPA's 1981 Community Water System Survey, a typical ground water
CWS would face incremental individual lifetime cancer risk due to chlorination byproducts of
5x10'3. It should be emphasized that this risk is based on average and median THM occurrence
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information that does not segregate systems that disinfect from those that do. Further, the NAS
Report points out that this average DBF risk is smaller than the average individual lifetime fatal
cancer risk associated with baseline radon exposures from ground water (untreated for radon),
which is estimated at 1.2 x 10~4 using a mean radon concentration of 213 pCi/1.
A more meaningful comparison is to look at the trade-off between risk reduction from
radon treatment in cases where disinfection is added with the added risks from DBF formation.
This trade-off will affect only a minority of systems since a majority of ground water systems
already have disinfection in place. For the smallest systems size category, approximately half of
all CWSs already have disinfection in place. The proportion of systems having disinfection in
place increases as the size categories increase, up to >95% for large systems (Table 5-2). In
addition, although EPA is using the conservative costing assumption that all systems adding
aeration or GAG would disinfect, not all systems adding aeration or GAG would have to add
post-disinfection or, if disinfecting, may use a disinfection technology that does not forms DBFs.
For those ground water systems adding treatment with disinfection, this trade-off tends to be
favorable since the combined risk reduction from radon removal and microbial risk reduction
outweigh the added risk from DBF formation.
An estimate of the risk reduction due to treatment of radon in water for various removal
percentages and finished water concentrations is provided hi Table 3.7. As noted by the NAS
Report, these risk reductions outweigh the increased risk from DBF exposure for those systems
that chlorinate as a result of adding radon treatment.
The ratios between risk reduction from radon removal and the risks from THMs at levels
equal their MCLs (a conservative assumption) are shown in Table 3.8. The data indicate that the
risk ratios are favorable for treatment with disinfection, ignoring microbial risk reduction, even
assuming the worst case scenario that ground water systems have THM levels at the MCL. It is
worth noting that there is the possibility that accounting quantitatively for the increased risk from
DBF exposure for systems adding chlorination in conjunction with treatment for radon may
somewhat decrease the monetized benefits estimates.
Other Factors: Uncertainty in Risk, Benefit, and Cost Estimates
Estimates of health benefits from radon reduction are uncertain. A few of the variables
affecting the uncertainty in the benefit estimates include the distribution of radon in ground
water systems, the NAS's risk models for ingestion and inhalation risks, and the transfer factor
used to estimate indoor air radon activity levels. EPA plans to include an uncertainty analysis of
radon in drinking water risks with the proposed rule. Monetary benefit estimates are also
strongly affected by the VSL estimate that is used for fatal cancers. The WTP valuation for non-
fatal cancers has less impact on benefit estimates because it contributes less than 1 percent to the
total benefits estimates, due to the fact that there are few non-fatal cancers relative to fatal
cancers.
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Estimates of the regulatory costs also have associated uncertainty. The major factors
affecting this uncertainty include assumptions regarding the distribution of radon levels among
ground water systems and among treatment sites within systems, uncertainties in unit cost
models, the assumed prevalence of the various compliance decisions, and the exclusion of
NTNCWSs in the HRRCA's national cost estimates.
To deal with a lack of information regarding the intra-system variability of radon levels
between treatment sites (source wells), the national cost estimates are based on the assumption
that all CWSs above a target radon level, as estimated by system-level average radon occurrence
predictions from the occurrence model, will install separate treatment systems at each site.
Ideally, occurrence information at each treatment site will provide a better estimate of national
costs, since the wells within a water system would exhibit a range of radon occurrence levels,
some of which may be below the target radon level, others above this level. Since it is not
obvious whether the system-level approach will lead to either a positive or negative bias in the
national cost estimates, EPA is in the process of performing an analysis of the intra-system
variability for radon occurrence and will include this analysis in support of the upcoming
proposed rule.
There are also significant uncertainties in estimated treatment unit costs and in the
decision-trees that are used to model national level compliance decisions that will by made by
the system-size stratified universe of drinking water systems in response to a range of radon
influent levels. It is possible to estimate the uncertainties in both the unit costs and the decision-
tree by performing sensitivity analyses for the factors affecting costs. Regarding unit costs, this
analysis leads to a spread in costs that adequately resembles the "real-world" as shown by ranges
in treatment cost case studies. Regarding the uncertainty in the decision-tree, it is unfortunately
not possible to verify results in this way. However, since there are so few technologies to
mitigate radon in water, the decision-tree is fairly robust.
Other Impacts: Costs and Benefits of Multimedia Mitigation Program Implementation
Scenarios
In addition to evaluating the costs and benefits across a range of radon levels, two
scenarios were evaluated that reduce radon exposure through the use of MMM programs. The
two scenarios evaluated assume: (1) 50 percent of States (all water systems in those States) select
MMM implementation; and (2) 100 percent of States select MMM. These two scenarios are
described in detail in Section 7. For the MMM implementation analysis, systems were assumed
to mitigate water to the 4,000 pCi/1 Alternative Maximum Contaminant Level (AMCL), if
necessary, and that equivalent risk reduction between the AMCL and the radon level under
evaluation would be achieved through a MMM program. Therefore, the actual number of cancer
cases avoided is the same for the MMM implementation scenarios as for the water mitigation
only scenario.
In calculating the cost of MMM programs, the cost per fatal cancer case avoided was
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estimated at $700,000 (1997$). This value was originally estimated by EPA in 1992 using 1991
data. The same nominal value is used in the HRRCA based on anecdotal evidence from EPA's
Office of Radiation and Indoor Air (ORIA) that there has been an equivalent offset between a
decrease in testing and mitigation costs since 1991 and the expected increase due to inflation in
the years 1992-1997. This dollar amount reflects that real testing and mitigation costs have
decreased, while nominal costs have remained approximately constant.
Tables 7-2 and 7-3 illustrate that, as expected, the costs of reducing radon exposures
decrease with increasing numbers of States (i.e. CWSs) selecting the MMM implementation
scenario. Also, as would be expected, the annual costs of implementing MMM are, on average,
lower compared to reducing radon exposures in drinking water alone. Central tendency
estimates of the total annualized benefits exceed the annualized costs for both the 50 and 100
percent MMM participation scenarios over all radon levels. The cost per fatal cancer case
avoided is also lower for both the 50 and 100 percent MMM implementation scenarios compared
to the scenario in which no States elect to develop a MMM program. In addition, the cost per
fatal cancer case avoided is significantly lower for the MMM scenario with 100 percent of the
States electing the MMM program compared to when 50 percent of the States choose the MMM
scenario, especially at the lower radon levels. The costs and benefits estimates are also broken
out into their respective MMM and water mitigation components. With the exception of
4000pCi/l (the NAS estimated AMCL), annual monetized benefits are significantly larger than
annual costs for the MMM component of the total costs. For the water mitigation component,
the annual costs are larger than the annual monetized benefits across all radon levels.
2. INTRODUCTION
2.1 Background
This Health Risk Reduction and Cost Analysis (HRRCA) provides the Environmental
Protection Agency's (EPA) analysis of potential costs and benefits of different target levels for
radon in drinking water. The HRRCA builds on several technical components, including
estimates of radon occurrence in drinking water supplies, analytical methods for detecting and
measuring radon levels, and treatment technologies. Extensive analyses of these issues were
undertaken by the Agency in the course of previous rulemaking efforts for radon and other
radionuclides. Using data provided by stakeholders, and from published literature, the EPA has
updated these technical analyses to take into account the best currently available information and
to respond to comments on the 1991 proposed regulation for radon in drinking water. As
required by the 1996 Safe Drinking Water Act (SDWA), EPA has withdrawn the proposed
regulation for radon in drinking water (US EPA 1997B) and will propose a new regulation by
August, 1999.
One of the most important inputs used by EPA in the HRRCA is the National Academy
of Sciences (NAS) September 1998 report "Risk Assessment of Radon in Drinking Water" (NAS
Report). EPA has used the NAS assessment of the cancer risks from radon in drinking water to
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estimate both the health risks posed by existing levels of radon in drinking water and also the
estimated cancer deaths potentially prevented by reducing radon levels. The NAS Report is the
most comprehensive accumulation of scientific data gathered to date on radon in drinking water.
SDWA required the NAS assessment, which generally affirms EPA's earlier scientific
conclusions and analyses on the risks of exposure to radon and progeny in drinking water.
The analysis presented in this HRRCA uses updated estimates of the number of active
public drinking water systems obtained from EPA's Safe Drinking Water Information System
(SDWIS). Treatment costs for the removal of radon from drinking water also have been updated.
The HRRCA follows EPA policies with regard to the methods and assumptions used in cost and
benefit assessment.
In updating key analyses and developing the framework for the cost-benefit analysis
presented in the HRRCA, EPA has consulted with a broad range of stakeholders and technical
experts. Participants in a series of stakeholder meetings held in 1997 and 1998 included
representatives of public water systems, State drinking water and indoor air programs, tribal
water utilities and governments, environmental and public health groups, and other federal
agencies. EPA convened an expert panel in Denver in November of 1997 to review treatment
technology costing approaches. The panel made a number of recommendations for modification
to EPA cost estimating protocols that have been incorporated into the radon cost estimates. EPA
also consulted with a subgroup of the National Drinking Water Advisory Council(NDWAC) on
evaluating the benefits of drinking water regulations. The NDWAC was formed in accordance
with the Federal Advisory Committee Act (FACA) to assist and advise EPA. A variety of
stakeholders participated in the NDWAC benefits working group, including utility company
staff, environmentalists, health professionals, State water program staff, a local elected official,
economists, and members of the general public.
The American Water Works Association (AWWA) convened a "Radon Technical Work
Group," in 1998 that provided technical input on EPA's update of technical analyses
(occurrence, analytical methods, and treatment technology), and discussed conceptual issues
related to developing guidelines for multimedia mitigation programs. Members of the Radon
Technical Work Group included representatives from State drinking water and indoor air
programs, public water systems, drinking water testing laboratories, environmental groups and
the U.S. Geological Survey. EPA also held a series of conference calls with State drinking water
and indoor air programs, to discuss issues related to developing guidelines for multimedia
mitigation programs.
2.2 Regulatory History
Section 1412 of the Safe Drinking Water Act (SDWA), as amended in 1986, requires the
EPA to publish Maximum Contaminant Level Goals (MCLGs) and to promulgate National
Primary Drinking Water Regulations (NPDWRs) for contaminants that may cause an adverse
effect on human health and that are known or anticipated to occur in public water supplies. In
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response to this charge, the EPA proposed NPDWRs for radionuclides, including radon, in 1991
(US EPA 1991). The proposed rule included a maximum contaminant level (MCL) of 300 pCi/1
for radon in drinking water, applicable to both community water systems and non-transient non-
community water systems. A community water system (CWS) is defined as a public water
system with at least 15 or more service connections or that regularly serves at least 25 year-round
residents. A non-transient non-community system (NTNCWS) is a public water system that is
not a CWS and that regularly serves at least 25 of the same persons for at least six months per
year. Examples of NTNCWSs include those that serve schools, offices, and commercial
buildings. Under the proposed rule, all CWSs and NTNCWSs relying on ground water would
have been required to monitor radon levels quarterly at each point of entry to the distribution
system. Compliance monitoring requirements were based on the arithmetic average of four
quarterly samples. The 1991 proposed rule required systems with one or more points of entry
out of compliance to treat influent water to reduce radon levels below the MCL or to secure
water from another source below the MCL.
The proposed rule was accompanied by an assessment of regulatory costs and economic
impacts, as well as an assessment of the risk reduction associated with implementation of the
MCL. The Agency received substantial comments on the proposal and its supporting analyses
from States, water utilities, and other stakeholder groups. Comments from the water industry
questioned EPA's estimates of the number of systems that would be out of compliance with the
proposed MCL, as well as the cost of radon mitigation. EPA's Science Advisory Board (SAB)
provided extensive comments on the risk assessment used by the Agency to support the proposed
MCL. The SAB recommended that EPA expand the analysis of the uncertainty associated with
the risk and risk reduction estimates. In response to these comments, the assessment was revised
twice, once in 1993 and again in 1995 (US EPA 1995). Both of the revised risk analyses
provided detailed quantitative uncertainty analysis.
2.3 Safe Drinking Water Act Amendments of 1996
In the 1996 Amendments to the Safe Drinking Water Act, Congress established a new
charter for public water systems, States, and EPA to protect the safety of drinking water supplies.
Among other mandates, amended Section 1412(b)(13) directed EPA to withdraw the drinking
water standards proposed for radon in 1991 and to propose a new MCLG and NPDWR for radon
by no later than August 6, 1999. As noted above, the amendments require NAS to conduct a risk
assessment for radon in drinking water and an assessment of risk reduction benefits from various
mitigation measures to reduce radon in indoor air (Section 1412(b)(13)(B)). In addition, the
amendments introduce two new elements into the radon in drinking water rule: (1) an Alternative
Maximum Contaminant Level (AMCL) and (2) multimedia radon mitigation (MMM) program.
If the MCL established for radon in drinking water is more stringent than necessary to
reduce the contribution to radon in indoor air from drinking water to a concentration that is
equivalent to the national average concentration of radon in outdoor air, EPA is required to
simultaneously establish an AMCL that would result in a contribution of radon from drinking
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water to radon levels in indoor air equivalent to the national average concentration of radon in
outdoor air (Section 1412(b)(13)(F)). If an AMCL is established, EPA is to publish guidelines
for State programs, including criteria for multimedia measures to mitigate radon levels in indoor
air, to comply with the AMCL.
States may develop and submit to EPA for approval an MMM program to decrease radon
levels in indoor air (Section 1412(b)(l 3)(G)). These programs may rely on a variety of
mitigation measures, including public education, testing, training, technical assistance,
remediation grants and loan or incentive programs, or other regulatory and non-regulatory
measures. EPA shall approve a State's program if it is expected to achieve equal or greater
health risk reduction benefits than would be achieved by compliance with the more stringent
MCL. If EPA does not approve a State program, or a State does not propose a program, public
water supply systems may propose their own MMM programs to EPA, following the same
procedures outlined for States. Once the MMM programs are established, EPA is required to re-
evaluate them no less than every five years.
2.4 Specific Requirements for the Health Risk Reduction and Cost Analysis
Section 1412(b)(13)(C) of the 1996 Amendments requires EPA to prepare a Health Risk
Reduction and Cost Analysis (HRRCA) to be used to support the development of the radon
NPDWR. SDWA requires the HRRCA be published for public comment by February 6, 1999,
six months before the rule is to be proposed. In the preamble of the proposed rule, EPA must
include a response to all significant public comments on the HRRCA.
The HRRCA must also satisfy the requirements established in Section 1412(b)(3)(C) of
the amended SDWA. According to these requirements, EPA must analyze each of the following
when proposing an NPDWR that includes a MCL: (1) quantifiable and non-quantifiable health
risk reduction benefits for which there is a factual basis in the rulemaking record to conclude that
such benefits are likely to occur as the result of treatment to comply with each level; (2)
quantifiable and non-quantifiable health risk reduction benefits for which there is a factual basis
in the rulemaking record to conclude that such benefits are likely to occur from reductions in co-
occurring contaminants that may be attributed solely to compliance with the MCL, excluding
benefits resulting from compliance with other proposed or promulgated regulations; (3)
quantifiable and non-quantifiable costs for which there is a factual basis in the rulemaking record
to conclude that such costs are likely to occur solely as a result of compliance with the MCL,
including monitoring, treatment, and other costs, and excluding costs resulting from compliance
with other proposed or promulgated regulations; (4) The incremental costs and benefits
associated with each alternative MCL considered; (5) the effects of the contaminant on the
general population and on groups within the general population, such as infants, children,
pregnant women, the elderly, individuals with a history of serious illness, or other subpopulations
that are identified as likely to be at greater risk of adverse health effects due to exposure to
contaminants in drinking water than the general population; (6) any increased health risk that
may occur as the result of compliance, including risks associated with co-occurring
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contaminants; and (7) other relevant factors, including the quality and extent of the information,
the uncertainties in the analysis, and factors with respect to the degree and nature of the risk.
To the extent possible, this HRRCA follows the new cost-benefit framework being
developed by the Office of Ground Water and Drinking Water (OGWDW) . As provided in the
SDWA, as amended, the HRRCA discusses the costs and benefits associated with a variety of
radon levels. Summary tables and figures are presented that characterize aggregate costs and
benefits, impacts on affected entities, and tradeoffs between risk reduction and compliance costs.
More in-depth discussions of input data and assumptions will be provided in a companion
"Analytical Support Document" and an in-depth presentation and discussion of the results will
appear in a separate "Cost/Benefit Document" that will accompany the proposed rule The
HRRCA by itself does not constitute the complete Regulatory Impact Analysis (RIA), but serves
as a foundation upon which the RIA can be developed for the proposed rule.
2.5 Radon Levels Evaluated
The HRRCA is intended to present preliminary estimates of the potential costs and
benefits of various levels of controlling radon in drinking water. The HRRCA assumes that all
systems drawing water from sources above a defined radon level will employ treatment
technologies to meet the target level or "regionalize" to obtain water from another source with
lower radon levels. This analysis evaluates radon levels of 100, 300, 500, 700, 1,000, 2,000, and
4,000 pCi/1. The analysis did not include any provisions for exemptions or phased compliance
and assumed that a simple quarterly monitoring scheme would be used to determine the need for
mitigation and ongoing compliance.
The HRRCA also evaluates national costs and benefits of MMM implementation
scenarios, with States choosing to reduce radon exposure in drinking water through an
Alternative Maximum Contaminant Level (AMCL) and radon risks in indoor air through MMM
programs. Based on NAS recommendations, the AMCL level that is evaluated is 4,000 pCi/1.
Under the scenarios that include an AMCL, the HRRCA assumes that a portion of the States
would adopt an AMCL supplemented with MMM programs to address indoor air radon risks. In
the absence of information concerning the number of States that would choose to implement
radon risk reduction through the use of AMCL plus multimedia programs, the HRRCA assumes
that either 50 or 100 percent of the systems in the United States would choose to implement
MMM programs and comply with the AMCL. For the MMM implementation scenarios, a single
multimedia cost estimate is used, based on the cost-effectiveness of current voluntary mitigation
efforts. These issues are discussed in more detail in Section 7.
2.6 Document Structure
The HRRCA is organized into 7 sections and a number of appendices. The appendices,
while not included in this Federal Register Notice, are available in the docket for review and can
be downloaded from the web at www.epa.gov/safewater/standard/pp/radonpp/html. Section 3
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discusses the health effects of exposure to radon. Section 4 describes the assumptions and
methods for estimating quantifiable benefits and assessing non-quantifiable benefits. Section 5
discusses the water treatment and MMM methods used to calculate the national costs of the
various radon levels examined. Section 6 presents the results of the cost and benefit analysis of
reducing radon levels in drinking water, and evaluates economic impacts on households. In
addition, the major sources of uncertainty associated with the estimates of costs, benefits, and
economic impacts are identified. Section 7 estimates the costs and benefits of two different
implementation scenarios in which States and water systems elect to develop and implement a
MMM program and comply with the AMCL. Appendices provide details of the risk
calculations, cost curves for treatment technologies, methods used to calculate system flows, and
detailed breakdown summaries of the cost, benefit and impact calculations.
3. HEALTH EFFECTS OF RADON EXPOSURE
This Section presents an overview of the major issues and assumptions addressed in order
to characterize the health impacts and potential benefits of reductions in radon exposures. The
methods that have been used to characterize risk and benefits in the HRRCA are also described.
The assumptions and methods presented below are used in Section 4 to derive detailed estimates
of the health reduction benefits of different radon levels in ground water supplies.
3.1 Radon Occurrence and Exposure Pathways
As part of the regulatory development process, EPA has updated and refined its analysis
of radon occurrence patterns in ground water supplies in the United States (US EPA 1998L).
This new analysis incorporates information from the EPA 1985 National Inorganic and
Radionuclides Survey (NIRS) of 1000 community ground water systems throughout the United
States, along with supplemental data provided by the States, water utilities, and academic
researchers.
The new study also addressed a number of issues raised by public comments on the
previous occurrence analysis. These include characterization of regional and temporal variability
in radon levels, variability in radon levels across different-sized water systems, impact of
sampling point, and the proper statistical techniques for evaluating the data.
3.1.1 Occurrence
Radon is a naturally occurring volatile gas formed from the normal radioactive decay of
uranium. It is colorless, odorless, tasteless, chemically inert, and radioactive. Uranium is present
in small amounts in most rocks and soil, where it decays to other products including radium, then
to radon. Some of the radon moves through air or water-filled pores in the soil to the soil surface
and enters the air, while some remains below the surface and dissolves in ground water (water
that collects and flows under the ground's surface). Due to their very long half-life (the time
required for half of a given amount of a radionuclide to decay), uranium and radium persist in
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rock and soil.
Radon itself undergoes radioactive decay and has a radioactive half-life of about four
days. When radon atoms decay they emit radiation in the form of alpha particles, and transform
into decay products, or progeny, which also decay. Unlike radon gas, these progeny easily attach
to and can be transported by dust and other particles in air. The decay of progeny continues until
stable, non-radioactive progeny are formed. At each step in the decay process, radiation is
released. The term radon, as commonly used, refers to radon-222 as well as its radioactive decay
products.
In general, radon levels in ground water in the United States have been found to be the
highest in New England and the Appalachian uplands of the Middle Atlantic and Southeastern
States (Figure 3-1). There are also isolated areas in the Rocky Mountains, California, Texas, and
the upper Midwest where radon levels in ground water tend to be higher than the United States
average. The lowest ground water radon levels tend to be found in the Mississippi Valley, lower
Midwest, and Plains States. When comparing radon levels in ground water to radon levels in
indoor air at the State level, the distribution of radon concentrations in indoor air (Figure 3-2) do
not always mirror distributions of radon in ground water.
In addition to large-scale regional variation, radon levels in ground water also vary
significantly over smaller distance scales. Local differences in geology tend to greatly influence
the patterns of radon levels observed at specific locations (e.g., not all radon levels in New
England are high; not all radon levels in the Gulf Coast region are low). Over small distances,
there is often no consistent relationship between measured radon levels in ground water and
radium levels in the ground water or in the parent bedrock (Davis and Watson 1989). Similarly,
no significant national correlation has been found between radon levels in individual ground
water systems and the levels of other inorganic contaminants or conventional geochemical
parameters. Potential correlations between radon levels and levels of organic contaminants in
ground water have not been investigated, but there is little reason to believe any would be found.
Radon's volatility is rather high compared to its solubility in water. Thus, radon volatilizes
rapidly from surface water, and measured radon levels in surface water supplies are generally
insignificant compared to those found in ground water.
25
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Figure 3-1. General Patterns of Radon Occurrence in Groundwater in the United States
General Patterns of Radon Occurrence in Groundwater in the United States
Mean Radon in Groundwater
pCiA
H •ISO to 2,000
H 30010 450
[! 15010 300
D Less than ISO
Source: USEPANKS Surrey, 1985
Note: State averaging of data may obscure local variations in radon levels.
26
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Figure 3-2. EPA Map of Radon Zones in Indoor Air
EPA Map of Radon Zones in Indoor Air
Zone designation for Puerto Rico is under development
The purpose of this nap is to assist National, State, and local organizations to target their
resources and to implement radon-resistant building codes. This map is not intended to be used
to determine if a home in a given zone should be tested for radon. Homes with elevated levels
of radon have been found in all three zones. All homes should be tested regardless of
geographic location.
IMPORTANT: Consult the EPA Map of Radon Zones document (EPA-402-R-Q3-Q71) before using this map. This document contains information on radon potential
variations within counties. EPA also recommends that mis map be supplemented with any available local data in order to further understand and predict
the radon potential of a specific area.
Guam • Preliminary Zons designation
Legend Key:
Zone 1 - Counties have a predicted average indoor screening level greater than 4 pCi/L.
Zone 2 - Counties have a predicted average indoor screening level between 2 and 4 pCi/L.
Zone 3 - Counties have a predicted average indoor screening level less than 2 pCi/L.
-------
Because of its short half life, there are relatively few man-made sources of radon
exposure in ground water. The most common man-made sources of radon ground water
contamination are phosphate or uranium mining or milling operations and wastes from thorium
or radium processing. Releases from these sources can result in high ground water exposures,
but generally only to very limited populations; for instance, to persons using a domestic well in a
contaminated aquifer as a source of potable water (US EPA 1994B).
Table 3-1 summarizes the regional patterns of radon in drinking water supplies as seen in
the NIRS database. This survey of 1,000 ground water systems, undertaken by EPA in 1985,
provides the most representative national characterization of radon levels in drinking water.
However, the NIRS has the disadvantage that the samples were all taken from within the
water distribution systems, making estimation of the naturally occurring influent radon levels
difficult. In addition, the NIRS data provide no information to allow analysis of the variability of
radon levels over time or within individual systems.
Table 3-1. Radon Distributions by Region (All System Sizes)
Region
Appalachian
California
Gulf Coast
Great Lakes
New England
Northwest
Plains
Rocky Mountains
Arithmetic Mean
(pCi/1)
1,127
629
263
278
2,933
222
213
607
Geometric Mean*
(pCi/1)
333
333
125
151
1,214
161
132
361
Geometric Standard
Deviation**
(pCi/1)
4.76
3.09
3.38
3.01
3.77
2.23
2.65
2.77
Source: US EPA 1998L. The values given are not population-weighted, but reflect averages across systems.
* The geometric mean is the anti-log of the average of the logarithms (log base e) of the observations.
** The geometric standard deviation is the anti-log of the standard deviation of the logarithms (log base e) of the
observations.
The NIRS data illustrate the wide regional variations in radon levels in ground water. The
arithmetic mean and geometric mean radon levels are substantially higher in New England and
the Appalachian region (in this analysis, all the States on the east coast between New York and
Florida) than in other regions of the United States. The large differences between the geometric
28
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(anti-log of the average of the logarithms (log base e) of the observations) and arithmetic means
indicate how "skewed" (i.e., "stretched" in a positive direction; a bell-shaped curve with a tail out
to the right) the radon distributions are. The Agency selected a lognormal model as the best
approach to evaluating these data.
EPA's current re-evaluation of radon occurrence in ground water uses data from a
number of additional sources to supplement the NIRS information and to develop estimates of
the national distribution of radon in ground water systems of different sizes. Data from 17 States
were used to evaluate the differences between radon levels in ground water and radon levels in
distribution systems in the same regions. The results of these comparisons were used to estimate
national distributions of radon occurrence in ground water. Table 3-2 summarizes EPA's latest
characterization of the distributions of radon levels in ground water supplies of different sizes
and populations exposed to radon through CWSs.
In this table, radon levels and populations are presented for systems serving various
population ranges from 25 to greater than 100,000. For purpose of estimating costs and benefits,
the CWSs are aggregated to be consistent with the following system size categories identified in
the 1996 SDWA, as amended: very very small systems (25-500 people), further subdivided into
25-100 and 101-500; very small systems (501-3,300 people); small systems (3,301-10,000
people); medium systems (10,001-100,000 people); and large systems (greater than 100,000
people).
In the updated occurrence analysis, insufficient data were available to accurately assess
radon levels in the highest CWSs size stratum. Thus, data from the two largest size strata were
pooled to develop exposure estimates for the risk and benefits assessments.
The Agency estimates that approximately 89.7 million people are served by community
ground water systems in the United States based on an EPA analysis of SDWIS data in 1998).
The data in Table 3-2 show that systems serving more than 500 people account for
approximately 95 percent of the population served by ground water systems, even though they
represent only 40 percent the total active systems (USEPA 1997A). The estimated system
geometric mean radon levels range from approximately 120 pCi/1 for the largest systems to 312
pCi/1 for the smallest systems. Arithmetic mean values for the various size categories range from
175 pCi/1 to 578 pCi/1, and the population-weighted arithmetic mean radon level across all the
community ground water supplies is 213 pCi/1.
29
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Table 3-2. Radon Distributions in Public Water Systems
Total Systems
Geometric Mean Radon
Level, pCi/1
Geometric Standard
Deviation
Population Served
(Millions)
Radon Level, pCi/1
100
300
500
700
1000
2000
4000
System Size (Population Served)
25-100
14,651
312
3.0
0.87
101-500
14,896
259
3.3
4.18
501-3,300
[ 10,286
122
3.2
14.2
3,301-10,000
2,538
124
2.3
14.5
>10,000
1,536
132
2.3
65.9
Proportions of Systems Exceeding Radon Levels (percent)
84.7
51.4
33.6
23.4
14.7
4.7
1.1
78.7
45.1
29.1
20.3
12.9
4.4
1.1
56.9
22.1
11.4
6.8
3.6
0.8
O.I
60.4
14.3
4.6
1.8
0.6
0.0
0.0
62.9
16.2
5.5
2.3
0.8
0.1
0.0
Table 3-3 presents the total exposed population above each radon level by system size
category. Approximately 20% of the total population for all system sizes are above the radon
level of 300 pCi/1 and 63% are above a radon level of 100 pCi/1.
30
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Table 3-3. Population Exposed Above Various Radon Levels By System Size (Thousands)
Radon
level
(pCi/1)
4,000
2,000
1,000
700
500
300
100
Very
Very
Small
25-100
9.4
41
128
202
290
445
733
Very
Very
Small
101-500
46
183
541
848
1,210
1,880
3,290
Very Small
501-3,300
20
119
513
962
1,620
3,140
8,080
Small
3,301-lOK
0.2
5.7
85.5
267
672
2,080
8,760
Medium
10K-100K
0.9
21.7
289
859
2,070
6,060
23,400
Large
>100K
0.4
11.0
147
436
1,050
3,070
11,900
Total
77.2
381
1,695
3,558
6,893
16,641
56,054
Radon exposures also arise from NTNCWSs. The Agency estimates that approximately
5.2 million people use water from NTNCWSs (US EPA 1998G). An analysis of SDWIS data in
1998 shows there are approximately 19,500 active NTNCWSs in the United States. Over 96
percent of these systems serve fewer than 1,000 people. EPA recently identified useful data on
radon levels in NTNCWSs from six States. A preliminary analysis of data from these States
suggested that geometric mean radon levels are approximately 60 percent higher in NTNCWSs
than in CWSs in the same size category.
There are currently no data which enable the agency to determine the extent to which the
populations exposed to radon from CWSs and NTNCWSs overlap. Some portion of individuals
exposed through a CWS at home may be exposed to radon from a NTNCWS at school or at
work. Similarly, the same populations may be exposed to radon from two different community
systems in the course of their normal daily activities. Further, in the case of NTNCWSs, it is
possible that the same individual could be exposed sequentially throughout their life to radon
from a series of different systems; at school, then at work, etc.
3.1.2 Exposure Pathways
People are exposed to radon in drinking water in three ways: from ingesting radon
dissolved in water; from inhaling radon gas released from water during household use; and from
inhaling radon progeny derived from radon gas released from water.
Typically, indoor air contamination arising from soil gas accounts for the bulk of total
individual risk due to radon exposure (NAS 1998B). Nationally, levels of radon in household air
average approximately 1.25 pCi/1 (US EPA 1992 A). Usually, the bulk of the radon enters indoor
air by diffusion from soils through basement walls or foundation cracks or openings. Radon in
31
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domestic water generally contributes a small proportion of the total radon in indoor air. The
NAS recommends that EPA use the central estimate of a transfer factor of 1.0 pCi/1 for radon in
domestic water contributing IxlO"4 pCi/1 to indoor air. As an example, for a typical ground water
CWS with a radon level of 250 pCi/1, the increment in indoor air activity would be 0.025 pCi/1.
This is about 2 percent of the average indoor level, which is derived mostly from soils.
As noted, the bulk of radiation exposure through inhalation comes from radon progeny,
which tend to bind to airborne particulates. When the particles are inhaled, they become
deposited in the respiratory tract, and further radioactive decay results in a radiation dose to the
respiratory epithelium. In contrast, when radon gas is inhaled, it is absorbed through the lung,
and much of this fraction remains in the body only a short time before being exhaled.
Direct ingestion of radon gas in water is the other important exposure pathway associated
with domestic water use. If water is not agitated or heated prior to consumption, the bulk (80 to
100 percent) of the radon remains in the water and is consequently ingested with it (US EPA
1995). Heating, agitation (for example, by a faucet aerator), and prolonged standing cause radon
to be released and the proportion consumed to be reduced. After a person ingests radon in water,
the radon passes from the gastrointestinal tract into the blood. The blood then circulates the
radon to all organs of the body before it is eventually exhaled from the lungs. When radon and
its progeny decay in the body, the surrounding tissues are irradiated by alpha particles. However,
the dose of radiation resulting from exposure to radon gas by ingestion varies from organ to
organ. Stomach, followed by the tissues of colon, liver, kidney, red marrow, and lung appear to
receive the greatest doses.
Exposure patterns to radon vary with different exposure settings. Depending on the
relative radon levels in water and air, water use patterns, and exposure frequency and duration,
the relative contribution of ingestion and inhalation exposure to total risks will vary. In the case
of domestic water use, inhalation of radon progeny accounts for most of the total individual risk
resulting from radon exposure (Section 3.2). Inhalation exposure to radon from NTNCWSs is
expected to be less than for CWSs, however, because buildings served by these systems tend to
be larger, and ventilation rates higher, than the corresponding values for domestic exposures. In
addition, exposure at these facilities tend to be less frequent and of shorter duration than
exposure from CWSs. Therefore, overall exposures at NTNCWSs will likely be lower.
3.2 Nature of Health Impacts
Exposure to radon and its progeny is believed to be associated with increased risks of
several kinds of cancer. When radon or its progeny are inhaled, lung cancer accounts for most of
the total incremental cancer risk (NAS 1998 A). Ingestion of radon in water is suspected of being
associated with increased risk of tumors of several internal organs, primarily the stomach (NAS
1998B). As discussed previously, NAS recently estimated the lifetime unit fatal cancer risks
associated with exposure to radon from domestic water use for ingestion and inhalation
pathways. EPA subsequently calculated the unit risk of inhalation of radon gas to 0.06 percent of
the total risk from radon in drinking water, using radiation dosimetry data and risk coefficients
32
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provided by the NAS (NAS 1998B). The lifetime unit fatal cancer risk is defined as the lifetime
risk associated with exposures to a unit concentration (1 pCi/1) of radon in drinking water. The
findings are summarized in Table 3-4.
Table 3-4. Estimated Radon Unit Lifetime Fatal Cancer Risks in
Community Water Systems
Exposure Pathway
Inhalation of radon progeny1
Ingestion of radon1
Inhalation of radon gas2
Total
Cancer Unit Risk per pCi/1 in
Water
5.55X10'7
7.00X1 0'8
3.50X10'10
6.25X1 0'7
Proportion of Total Risk
(Percent)
89
11
0.06
100
1. Source: NAS 1998B.
2. Source: Calculated by EPA from radiation dosimetry data and risk coefficients provided by NAS (NAS 1998B).
These updated risk estimates indicate that inhalation of radon progeny accounts for most
(approximately 89 percent) of the individual risk associated with domestic water use, with almost
all of the remainder (11 percent) resulting from ingestion of radon gas. Inhalation of radon
progeny is associated primarily with increased risk of lung cancer, while ingestion exposure is
associated primarily with elevated risk of stomach cancer. Ingestion of radon also results in
slightly increased risk cancer of the colon, liver, and other tissues. Inhalation of radon gas is
estimated to account for approximately 0.06 percent of the total risk from household radon
exposures, and the major target organ is again believed to be the lung. In the following sections,
methods and parameter values developed by the NAS are applied to the estimation of baseline
population risks and the levels of risk reduction associated with the different radon levels.
Radon, a noble gas, exhibits no other known toxic effects besides carcinogenesis. The
1998 NAS report indicates that there is no scientific evidence to show that exposure to radon is
associated with reproductive or genetic toxicity. Therefore, the endpoints characterized in the
risk assessment for radon exposure are primarily increased risk of lung and stomach cancers.
For the purposes of this Health Risk Reduction and Cost Analysis, EPA is using the best
estimates of radon inhalation and ingestion risks provided by the NAS Report. In order to
finalize the Agency's estimate of lung cancer deaths arising from indoor air exposure, EPA's
Office of Radiation and Indoor Air is currently assessing various factors integral to the approach
for estimating the lung cancer risks of inhaling radon progeny in indoor air provided in the NAS
1998 report "The Health Effects of Exposure to Radon-BEIR VI" (BEIR VI Report). This
assessment will be reviewed by the Agency's SAB and may result in some adjustment to the
33
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estimated unit risk, and its associated uncertainty, for inhalation of radon progeny used in this
HRRCA
3.3 Impacts on Sensitive Subpopulations
Populations that might experience disproportional risk as a result of radon exposure fall
into two general classes: those who might receive higher exposures per unit radon in water
supplies and those who are more sensitive to the exposures they receive. The former group
includes persons whose domestic water supplies have high radon levels, and whose physiological
characteristics or behaviors (high metabolic rate, high water consumption, large amounts of time
spent indoors) result in high exposures per unit of exposure concentration. As noted above, a
portion of the population could be exposed to radon from more than one source. For example, a
student or worker might be exposed to radon from the CWS in the household setting and also
from a NTNCWS (or from the same or different CWS) at school or work.
Different age and gender groups may also experience exposure dosimetric differences.
These differences in radiation dose per unit exposure have been taken into account in the BEIR
VI Report addressing radon in indoor air (NAS 1998A), the NAS Report addressing radon in
drinking water (NAS 1998B), and the EPA Federal Guidance Report 13 (US EPA 1998F).
The NAS Report concluded that there is insufficient scientific information to permit
separate cancer risk estimates for subpopulations such as pregnant women, the elderly, children,
and seriously ill persons. The report did note, however, that according to the NAS risk model for
the cancer risk from ingested radon, which accounts for 11% of the total lifetime fatal cancer risk
from radon in drinking water, approximately 30% of this fatal lifetime cancer risk is attributed to
exposure between ages 0 to 10.
The NAS did identify smokers as the only group that is more susceptible to inhalation
exposure to radon progeny. Inhalation to cigarette smoke and radon progeny result in a greater
increased risk than if the two exposures act independently to induce lung cancer.
3.4 Risk Reduction Model for Radon in Drinking Water
Risk and risk reduction were estimated using a Monte Carlo model that simulated the
initial and post-regulatory distributions of radon activity levels and population cancer risks. Each
iteration of the model selected a size stratum of community water systems. The system sizes
were stratified according to the following populations served: <100; 101-500; 501-3,300;
3,301-10,000; and > 10,000 served. For each size category, a lognormal distribution of
uncontrolled radon levels had been defined based on the updated occurrence analysis (USEPA
1998L). The model sampled randomly from the radon distribution for the selected CWS size
category to determine if the radon level was above the selected maximum exposure level. The
proportion of iterations choosing each size stratum were determined by the relative national
populations served by each size stratum of systems. Thus, over a large number of iterations
(generally, benefit calculations were carried out using 20,000 to 50,000 iterations), the model
34
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produced a population-weighted distribution of radon levels.
In each iteration of the model, the simulated influent radon activity level was compared to
the maximum radon levels under consideration (100, 300, 500,700, 1000,2000, and 4000 pCi/1).
When the simulated influent radon level was less than the target level, the simulated level was
passed directly to the risk calculation equations. The equations calculated population fatal cancer
risks from ingestion of radon gas, inhalation of radon gas, and inhalation of radon progeny using
standard exposure factors and unit risk values derived by the NAS.
When the simulated influent radon level in a given iteration exceeded a target radon level,
the model reduced the value by a proportion equivalent to the performance of selected mitigation
technologies. The degrees of reduction are presented in Table 3-5:
Table 3-5. Radon Treatment Assumptions to Calculate Residual Fatal Cancer Risks
If the Radon Level is :
Less than the target level
Above but less than two times the target level
Above two times but less than five times the
target level
Greater than five times the target level
Then the Treated Level is:
None; Influent = Effluent
Influent = 0.5 X Effluent
Influent = 0.2 X Effluent
Influent = 0.01 Effluent
Using this approach implies that a greater level of control is achieved than if all the
systems were simply assumed to reduce exposures to the maximum exposure level. For
example, a system with an initial uncontrolled concentration of 400 pCi/1 would need to employ
a mitigation technology with a 50 percent removal efficiency to comply with a maximum
exposure limit of 300 pCi/1, resulting in a final radon level of 200 pCi/1. Limited sensitivity
analysis suggests that this approach does not provide very much in the way of extra risk
reduction. The preponderance of population risk reduction is achieved by reducing radon levels
in the relatively few systems that have initial uncontrolled values far above the maximum
exposure limits, not by the relatively small incremental reductions below the target radon levels.
3.5 Risks from Existing Radon Exposures
In support of the regulatory development process for the revised radon rule, EPA has
updated its risk assessment for radon exposures in drinking water. Previously, EPA developed
estimates of risk from total population exposure to radon in drinking water in support of the
proposed rule for radon in 1991 (US EPA 1991). In response to comments from the SAB, EPA
updated the risk assessment to include an analysis of uncertainty in 1993 (US EPA 1993B). The
assessment was further revised to include revisions to risk factors and other variable values. The
latest uncertainty analysis was completed in 1995 (US EPA 1995).
35
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EPA's revised risk analysis in support of this HRRCA takes into account new data on
radon distributions and exposed populations developed in the updated occurrence analysis, as
well as new information on dose-response relationships developed by the NAS (NAS 1998B).
For the HRRCA, population risks are estimated using single-value "nominal" estimates of the
various exposure factors which determine individual risk, and Monte Carlo simulation
techniques are used to estimate risks associated with the distributions of radon exposures from
the various size categories of CWSs. The risk equations and parameter values used in the revised
risk assessment are summarized in Appendix A. EPA is currently conducting a comprehensive
uncertainty analysis of radon risks using two-dimensional Monte Carlo methods to better judge
the level of uncertainty associated with the radon risk estimates.
Table 3-6 summarizes the results of EPA's revised baseline risk assessment. Because the
NAS and EPA-derived dose-response and exposure parameters factors discussed above were
used in the risk assessment, the proportions of risk associated with the various pathways were the
same as shown in Table 3-4. The total estimated population risks associated with the current
distribution of radon in CWSs was 160 fatal cancers per year, 142 of which were associated with
progeny inhalation. Approximately 18 fatal cancers per year were associated with ingestion of
radon. These totals are similar to, but somewhat lower than, EPA's 1991 and 1993 baseline risk
estimates (USEPA 1994C). In comparison, there are an estimated 15,400 to 21,800 fatal lung
cancers per year due to inhalation of indoor air contaminated with radon emanating from soil and
bedrock (NAS 1998A).
The risks summarized in Table 3-5 do not include any contribution from NTNCWSs,
Thus, the potential baseline risks and benefits of a radon rule may be somewhat underestimated.
The limited available data concerning radon levels in NTNCWSs suggest that levels may be
considerably higher (perhaps by 60 percent, on average) than those in CWSs of similar size (US
EPA 1998L). However, it appears that the average exposure per unit activity in NTNCWSs is
likely to be lower than that for CWSs. Because of the expected lower inhalation exposures,
water ingestion rates, and frequencies and durations of exposure, the individual fatal cancer risk
associated with a NTNCWS is expected to be lower compared to a CWS with similar radon
levels. EPA is currently conducting additional analyses of NTNCWS exposures from radon in an
attempt to refine the current approximate risk estimates.
36
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Table 3-6. Annual Fatal Cancer Risks for Exposures to Radon
from Community Water Systems
Pathway
Inhalation of progeny
Ingestion of radon gas
Inhalation of radon gas
Total
Annual Unit Risk
(Fatal cancers per
person per year per
pCi/1 in water)1
7.44X10-9
9.30X10-'°
4.7X10'12
8.37X1 0'9
Annual Population
Risk (Fatal cancers
per year)2
142
17.8
0.1
160
Proportion of Total
Annual Risk (Percent)
89
11
0.06
100
Notes: 1. Derived using NAS lifetime unit fatal cancer risks.
2. Estimated through simulation analysis described in Section 3.4; the risk equations and parameter values
used in the simulation analysis are summarized in Appendix A.
3.6 Potential for Risk Reductions Associated with Removal of Co-Occurring Contaminants
Because radon is a naturally occurring ground water contaminant, its occurrence patterns
are not highly correlated with those of industrial pollutants. Similarly, the Agency's re-
evaluation of radon occurrence has revealed that the geographic patterns of radon occurrence are
not significantly correlated with naturally occurring inorganic contaminants that may pose health
risks. Thus, it is not likely that a relationship exists between the need to install radon treatment
technologies and treatments to remove other contaminants.
On the other hand, technologies used to reduce radon levels in drinking water have the
potential to reduce concentrations of other pollutants as well. All of the aeration technologies
discussed remove volatile organic contaminants, as well as radon, from contaminated ground
water. Similarly, GAC treatment for radon removal effectively reduces the concentrations of
organic (both volatile and nonvolatile) chemicals and some inorganic contaminants. Aeration
also tends to oxidize dissolved arsenic (a known carcinogen) to a less soluble form that is more
easily removed from water. The frequency with which radon treatment would also reduce risks
from other contaminants, and the extent of risk reduction that would be achieved, has not been
evaluated quantitatively in the HRRCA.
3.7 Potential for Risk Increases from Other Contaminants Associated with Radon Removal
As discussed in Section 5.1, the need to install radon treatment technologies may require
some systems that currently do not disinfect to do so. While case studies (US EPA 1998D) of
twenty-nine small to medium water systems that installed treatment (24 aeration, 5 GAC) to
remove radon from drinking water revealed only two systems that reported adding disinfection
(both aeration) with radon treatment (the systems either had disinfection already in place or did
37
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not add it), in practice the tendency to add disinfection may be much more significant than these
case studies indicate. EPA also realizes that the addition of chlorination for disinfection may
result in risk-risk tradeoffs, since, for example, the disinfection technology reduces potential for
infectious disease risk, but at the same time can result in increased exposures to disinfection by-
products (DBFs). This risk-risk trade-off is addressed by the recently promulgated Disinfectants
and Disinfection By-Products NPDWR (US EPA 19981). This rule identified MCLs for the
major DBPs, with which all CWSs and NTNCWSs will have to comply. These MCLs set a risk
ceiling from DBPs that water systems adding disinfection in conjunction with treatment for radon
removal could face. The formation of DBPs is proportional to the concentration of organic
precursor contaminants, which tend to be much lower in ground water than in surface water.
The NAS Report addressed several important potential risk-risk tradeoffs associated with
reducing radon levels in drinking water, including the trade-off between risk reduction from
radon treatment that includes post-disinfection with the increased potential for DBP formation
(NAS 1998B). The report concluded that, based upon median and average total trihalomethane
(THM) levels from EPA's 1981 Community Water System Survey, a typical ground water CWS
will face an incremental individual lifetime cancer risk due to chlorination byproducts of 5x10"5.
It should be emphasized that this risk is based on average, and median THM occurrence
information that does not segregate systems that disinfect from those that do. Further, the NAS
Report points out that this average DBP risk is smaller than the average individual lifetime fatal
cancer risk associated with baseline radon exposures from ground water (untreated for radon),
which is estimated at 1.2 x 10"4 using a mean radon concentration of 213 pCi/1.
A more meaningful comparison is to look at the trade-off between risk reduction from
radon treatment in cases where disinfection is added with the added risks from DBP formation.
This trade-off will affect only a minority of systems since a majority of ground water systems
already have disinfection in place. For the smallest systems size category, approximately half of
all CWSs already have disinfection in place. The proportions of systems having disinfection in
place increases as the size categories increase, up to >95% for large systems (Table 5-2). In
addition, although EPA is using the conservative costing assumption that all systems adding
aeration or GAC would disinfect, not all systems adding aeration or GAC would have to add
post-disinfection or, if disinfecting, may use a disinfection technology that does not forms DBPs.
For those ground water systems adding treatment with disinfection, this trade-off tends to be
favorable since the combined risk reduction from radon removal and microbial risk reduction
outweigh the added risk from DBP formation.
An estimate of the risk reduction due to treatment of radon in water for various removal
percentages and finished water concentrations is provided in Table 3.7, As noted by the NAS
Report, these risk reductions outweigh the increased risk from DBP exposure for those systems
that chlorinate as a result of adding radon treatment.
38
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Table 3-7. Radon Risk Reductions Across Various Effluent Levels and Percent Removals
% Removal1
60
80
90
99
Risk Reduction
@50 pCi/L
NA2
NA
2.8E-04
3.1E-03
Risk Reduction
@ 100 pCi/L
NA
2.5E-04
5.7E-04
6.2E-03
Risk Reduction
@ 200 pCi/L
1.9E-04
5.0E-04
1.1E-03
1.2E-02
Risk Reduction
@ 300 pCi/L
2.8E-04
7.6E-04
1.7E-03
1.9E-02
Notes: 1) Influent levels used in risk reduction calculations are determined by the relationship, Effluent Level
= Influent Level*(l - %Removal/100).
2) NA = Not applicable since associated influent level would be outside the range of realistic values
Comparing the risk reductions in Table 3.7 to the risks from THMs at their MCL values
(the maximum risk allowable under the DBF rule), the ratios between risk reduction from radon
removal and the conservative assumption that DBFs are present at their MCL values are shown
in Table 3.8.
Table 3-8. Radon Risk Reduction from Treatment Compared to DBF Risks
% Removal1
60
80
90
99
Estimated Risk Ratios
(Risk Reduction from Radon Removal / Risk from THMs at 0.080 mg/L)
Ratio @ 50
pCi/L
NA2
NA
2.4
26.0
Ratio @ 100
pCi/L
NA
2.1
4.7
52.0
Ratio @ 200
pCi/L
1.6
4.2
9.5
104.0
Ratio @ 300
pCi/L
2.4
6.3
14.2
155.9
^lotes: 1) Influent levels used in risk reduction calculations are determined by the relationship, Effluent Level
= Influent Level*(l - %Removal/100).
2) NA = Not applicable since associated influent level would be outside the range of realistic values
As can be seen in Table 3.8, the risk ratios are favorable for treatment with disinfection,
ignoring microbial risk reduction, even assuming the worst case scenario that ground water
systems have THM levels at the MCL. There is the possibility that accounting quantitatively for
the increased risk from DBF exposure for systems adding chlorination in conjunction with
treatment for radon may somewhat decrease the monetized benefits estimates.
39
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3.8 Risk for Ever-Smokers and Never-Smokers
As noted previously, cancer risks from inhalation of radon progeny are believed to be
greater for current and former smokers than for "never smokers". The NAS defines a "never
smoker" as someone who has smoked less than 100 cigarettes in their lifetime. Therefore, "ever
smokers" include current and former smokers. EPA and NAS have developed estimates of unit
risk values (estimates of cancer risks per unit of exposure) for radon progeny for "ever-smokers"
and "never-smokers" as shown in Table 3-9 (US EPA 1999A). The estimated unit risk values for
inhalation of radon progeny for ever-smokers (and therefore the individual and population risk) is
approximately 5.5 times greater than that for never smokers.
Because of estimated higher individual risks for smokers, this group accounts for a large
proportion of the overall population risk associated with radon progeny inhalation. The last two
columns of the table show that, given the current assumptions about smoking prevalence and the
relative impact of radon progeny on ever smokers and never smokers, about 85 percent of the
cancer cases from water exposures to progeny will occur in the ever-smoker population.
Table 3-9. Annual Lung Cancer Death Risk Estimates from Radon Progeny for Ever-
Smokers, Never-Smokers, and the General Population
Smoking
Status
Ever
Never
Combined
Annual Unit Risk
(Fatal cancer cases
per year per pCi/1
in water)
1.31X10-8
2.44X10-9
7.44X10-9
Average Annual
Individual Risk per
Year of Exposure
2.8X10-6
5.1X10-7
1.6X10-6
Annual Population
Risk (Fatal Cancers
per Year)
120
22
142
Proportion of
Total Annual
Population Risk
85
15
100
Source: EPA analyses derived from NAS (1998) estimates
Note: Ever-smoking prevalence was assumed to be 58 percent in males and 42 percent in females, and these rates
were assumed to be age independent.
4. BENEFITS OF REDUCED RADON EXPOSURES
4.1 Nature of Regulatory Benefits
4.1.1 Quantifiable Benefits
The benefits of controlling exposures to radon in drinking water take the form of avoided
cancers resulting from reduced exposures. Cancer risks (both fatal and non-fatal cancers per
year) are calculated using the risk model described in Section 3 for the baseline case (current
40
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conditions) and each of the radon levels. The health benefits of controls are estimated as the
baseline risks minus the residual risks associated with each radon level. The more stringent the
radon level, the lower the residual risks, and the higher the benefits.
The primary measures of regulatory benefits that are used in this analysis are the annual
numbers of fatal and non-fatal cancers prevented by reduced exposures. Due to a lack of
knowledge about how to account for the latency period for radon-induced cancers, it has been
assumed that risk reduction begins to accrue immediately after the reduction of exposures.
Exposures to radon and its progeny are associated with increases in lung cancer risks.
Ingestion of radon in drinking water is suspected of being associated primarily with increased
risks of tumors of the stomach, and with lesser risks to the colon, lung, and other organs. The
first column of Table 4-1 summarizes the estimates of the distribution of cancers by organ system
for inhalation and ingestion exposures given. For purposes of the risk assessment, inhalation of
progeny and radon gas are assumed to be associated exclusively with lung cancer risk. In the
case of radon ingestion, stomach cancer accounts for the bulk (approximately 87 percent) of the
total risk by this pathway. Cancers of several other organ systems account for far smaller
proportions of the cancer risk from radon ingestion, and are not included in this analysis.
Table 4-1. Proportion of Fatal Cancers by Exposure Pathway and Estimated Mortality
Exposure Pathway
Inhalation of progeny, radon gas
Ingestion of radon gas
Organ Affected
Lung
Stomach
Colon
Liver
Lung
General Tissue
Proportion of Fatal
Cancers by Organ and
Exposure Pathway
("percent V
89
9.5
0.4
0.3
0.2
0.5
Mortality
(percent)2
95
90
55
95
95
—
1. Source: US EPA analysis of dosimetry data and organ-specific risk coefficients (NAS 1998).
2. Source: US EPA analysis of National Cancer Institute mortality data.
The last column of Table 4-1 provides estimates of the mortality rate associated with the
various types of radon-associated cancers. These values are used in this analysis to estimate the
proportion of fatal and non-fatal cancers by organ system and exposure pathway. Both of the
cancers that account for the bulk of the risk from radon and progeny exposures (lung and
stomach) have high mortality rates.
4.1.2 Non-Quantifiable Benefits
Reductions in radon exposures might also be associated with non-quantifiable benefits.
EPA has identified several potential non-quantifiable benefits associated with regulating radon in
41
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drinking water. These include any peace of mind benefits specific to reduction of radon
exposure that may not be adequately captured in the VSL estimate. In addition, treating radon in
drinking water with aeration oxidizes arsenic into a less soluble form that is easier to remove
with conventional arsenic removal technologies. In terms of reducing radon exposures in indoor
air, it has also been suggested that provision of information to households on the risks of radon in
indoor air and available options to reduce exposure is a non-quantifiable benefit that can be
attributed to some components of a MMM program. Providing such information might allow
households to make informed choices about the appropriate level of risk reduction given their
specific circumstances and concerns. These potential benefits are difficult to quantify due to the
uncertainty surrounding their estimation. However, they are likely to be somewhat less in
magnitude relative to the monetized benefits estimates.
4.2 Monetization of Benefits
4.2.1 Estimation of Fatal and Non-Fatal Cancer Risk Reduction
The "direct" health benefits of the regulation, as discussed above, are the reduced streams
of cancer cases associated with reduced radon exposures. In this analysis, the data in Table 3-6
were used to estimate the numbers of fatal cancers of each organ system associated with
inhalation and ingestion pathway from the risk model described in Section 3.1. (These
proportions, by the nature of the risk model that is used, stay constant for all radon levels.)
Subsequently, the total number of cancers of each organ system was estimated. This is necessary
because the output of the risk model is fatal cancers, and the cost of illness and willingness to pay
for non-fatal cancers are only applied to individuals who survive the disease. The total number
of cancers per year of exposure, and the number of non-fatal cancers were estimated from the
fatal cancer numbers using the mortality data in Table 4-1. Thus, for example, a benefit of 100
cases of fatal lung cancer avoided implies approximately 105 total lung cancers avoided, five of
which are non-fatal. This calculation omits rounding error, and the total number of cases is equal
to the fatal cases divided by the mortality rate.
Fatal and non-fatal population cancer risks under baseline conditions were estimated first.
Then, the residual cancer risks were estimated for each of the radon levels. Consistent with the
assumptions made in the cost analysis, residual water radon levels were calculated using a similar
range of technology efficiencies. Radon levels were assumed to be reduced below baseline levels
by either 50, 80, or 99 percent, using the least stringent reduction which could comply with the
radon level under evaluation. Benefits took the form of the reductions in the numbers of fatal
and non-fatal cancers associated with each final level compared to the baseline risks.
4.2.2 Value of Statistical Life for Fatal Cancers Avoided
As one measure of potential benefits, this analysis assigns the monetary value of a
statistical life saved to each fatal cancer avoided. The estimation of the value of a statistical life
involves inferring individuals' implicit tradeoffs between small changes in mortality risk and
monetary compensation (US EPA 1998E). A central tendency value of $5.8 million (1997$) is
42
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used in the monetary benefits calculations, with low- and high-end values of $700,000 (1997$)
and $16.3 million (1997$), respectively, used for the purposes of sensitivity analysis. These
figures span the range of value of statistical life (VSL) estimates from 26 studies reviewed in
EPA's recent guidance on benefits assessment (US EPA 1998E) which is currently being
reviewed by EPA's SAB and the Office of Management and Budget (OMB). It is important to
recognize the limitations of existing VSL estimates and to consider whether factors such as
differences in the demographic characteristics of the populations and differences in the nature of
the risks being valued have a significant impact on the value of mortality risk reduction benefits.
As noted above, no separate medical care or lost-time costs are included in the benefits estimate
for fatal cancers because it is assumed that these costs are captured in the VSL for fatal cancers.
4.2.3 Costs of Illness and Lost Time for Non-Fatal Cancers
Two important elements in the estimation of the economic impacts of reduced cancer
risks for non-fatal cancers are the reductions in medical care costs and the costs of lost time. The
costs of medical care represent a net loss of resources to society (not considering the economic
hardship on the cancer patient and family). The cost of lost time represents the value of activities
that the individual must abandon (e.g., productive employment or leisure) as a result of radon-
induced cancer. Together, these two elements are often referred to as the costs of illness (COI).
Medical care and lost-time costs have been estimated for lung and stomach cancers,
which are the two most common types of rumors associated with radon exposures, and which
account for 99 percent of the total radon-associated cancers. Table 4-2 summarizes the Agency's
latest medical care and lost-tune cost estimates for lung cancer (US EPA 1998B, 1998C).
Medical care costs have been estimated from survey data for ten years after initial diagnosis. The
medical costs in the first year correspond to the costs of initial treatment, while medical costs in
subsequent years correspond to the average medical costs associated with monitoring and
treatment of recurrences among individuals who survive to that year. These out-year costs are
weighted by the proportion of patients surviving to the given year.
The lost time due to the radon-induced tumors is assumed to be concentrated in the first
year after diagnosis. This is why the out-year estimates for the costs of lost time in Table 2-8 are
all zero. The dollar costs of lost time given in the table are derived by assigning values lost
productive (work) and leisure (non-productive) hours. The costs given in the top row of Table
4-2 correspond to 776 lost productive hours and 1,493 lost leisure hours per patient. The
estimates of lost hours are relatively low for lung cancer primarily because the average age at
diagnosis is advanced (fewer than 34 percent of lung cancer patients are diagnosed before age
65).
Using a discount rate of seven percent, the estimated discounted present value in 1997
dollars of combined medical care and lost-time costs for a cancer survivor is approximately
$108,000. The estimated value varies with different discount rates. Using a discount rate of
three percent, combined costs are $121,600; at ten percent, combined costs are approximately
$100,200.
43
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Table 4-3 summarizes the estimation of medical and lost-time costs for survivors of
stomach cancer. The combined discounted costs for stomach cancer are similar to those for lung
cancer, but slightly higher. At a seven percent discount rate, combined discounted costs for
stomach cancer are approximately $114,000 (1997$). At three percent, they are about $126,300
(1997$). Discounted at ten percent, the average combined cost is $106,400 (1997$).
Table 4-2. Estimated Medical Care and Lost-Time Costs Per Case for
Survivors of Lung Cancer
Year after Diagnosis
1
2
3
4
5
6
7
8
9
10
Discounted Present Value
at 7 Percent
Total Discounted Value
n 997 dollars')
Medical Care Costs
(Undiscounted 1997
dollars)!
34,677
9,936
9,383
8,969
8,604
8,262
7,934
7,609
7,287
6,974
85,225
$108,287
Cost of Lost Leisure
(Undiscounted 1997
dollars)2
9,886
0
0
0
0
0
0
0
0
0
9,390
Cost of Lost
Productive Time
(Undiscounted 1997
dollars)2
14,393
0
0
0
0
0
0
0
0
0
13,671
Notes:
1. Medical care cost estimates derived from US EPA 1998B.
2. Lost productive and leisure hours estimates from US EPA 1998B; value of productive time estimated at
$12.47/hr, value of leisure hour estimated at $9.64/hour (from US EPA 1998J).
44
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Table 4-3. Estimated Medical Care and Lost-Time Costs Per Case
for Survivors of Stomach Cancer
Year after Diagnosis
1
2
3
4
5
6
7
8
9
10
Discounted Present
Value at 7 Percent
Total Discounted Value
n 997 dollars1)
Medical Care Costs
(Undiscounted 1997
dollars1*!
$37,507.28
$9,328.23
$8,749.24
$8,265.39
$7,829.62
$7,423.51
$7,035.81
$6,663.46
$6,300.32
$5,946.38
$82,997.35
$113,987
Cost of Lost Leisure
(Undiscounted 1997
dollars^2
$19,337.84
0
0
0
0
0
0
0
0
0
18,368
Cost of Lost Productive
Time (Undiscounted
1997dollars)2
13,288
0
0
0
0
0
0
0
0
0
12,621
Notes:
1. Medical care cost estimates derived from US EPA 1998C.
2. Lost productive and leisure hours estimates from US EPA 1998C; value of productive time estimated at
$12.47/hr, value of leisure hour estimated at $9.64/hour (from US EPA 1998J).
4.2.4 Willingness to Pay to Avoid Non-Fatal Cancers
As was the case for fatal cancers, willingness to pay (WTP) measures of the values of
avoiding serious non-fatal illness have also been developed. These WTP measures were
developed because the cost of illness estimates may be seen as understating total willingness to
pay to avoid non-fatal cancers. The main reason that the cost of illness understates total WTP is
the failure to account for many effects of disease-it ignores pain and suffering, defensive
expenditures, lost leisure time, and any potential altruistic benefits (US EPA 1998E). Recently,
EPA applied one such study to evaluate the benefits of avoiding non-fatal cancers in the
Regulatory Impact Analysis for the Stage I Disinfection By-Products Rule (US EPA 1998M).
That study estimated a range of WTP to avoid chronic bronchitis ranging from $168,600 to
$1,050,000 with a central tendency (mean) estimate of $536,000 (Viscusi et al. 1991). In the
benefits assessment, EPA uses the central tendency measure as a surrogate for the cost of
avoiding non-fatal cancers and an alternative to the cost of illness measures discussed above.
The high and low ends of the range are used in sensitivity analysis of the monetized benefit
estimates.
45
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4.3 Treatment of Monetized Benefits Over Time
The primary measures of regulatory benefits that are used in this analysis are the annual
numbers of expected fatal and non-fatal cancers prevented by reduced exposures to radon in
drinking water. The monetary valuation of fatal cancer risks used is a result of a benefits transfer
exercise from the risk of immediate accidental death to the risk of fatal cancer. No adjustments to
the benefits calculations have been made to reflect the time between the reduction in exposure and
the diagnosis and illness or possible death from cancer. Also, no adjustments have been made for
any other factors which might affect the valuation. Cancer valuations could be adjusted for how
they differ from accidental death valuations with respect to timing (latency) and with respect to
other factors that may affect individuals' willingness-to-pay for cancer risk reduction, including
dread, pain and suffering, the degree to which the risk is voluntary or involuntary, and the amount
by which life spans are shortened. Such adjustments have been under debate in the academic
literature. In the absence of quantitative evidence on the relative impact of each factor, EPA has
not adjusted the benefits estimates in this HRRCA to account for the factors discussed here. The
Agency is currently reviewing the various issues raised; at this time no Agency policy regarding
any such adjustments is in place.
5. COSTS OF RADON TREATMENT MEASURES
This section describes how the costs and economic impacts of reductions in radon
exposures were estimated. The most commonly used and cost-effective technologies for
mitigating radon are described, along with the degree of radon removal that can be achieved.
Costs of achieving specified radon removal levels for specific flow rates are discussed, along
with the need for pre-and post-treatment technologies. The methods used to estimate treatment
costs for single systems and aggregate national costs are explained, and the approach for
translating the costs into economic impacts on affected entities is also described.
5.1 Drinking Water Treatment Technologies and Costs
The two most commonly employed methods for removing radon from water supplies are
aeration and granular activated carbon (GAC) absorption. These treatment approaches can be
technically feasible and cost-effective over a wide range of removal efficiencies and flow rates.
In addition to the radon treatment technologies themselves, specific pre- or post-treatment
technologies may also be required. When influent iron and manganese levels are above certain
levels, pre-treatment may be required to remove or sequester these metals and avoid fouling the
radon removal equipment. Also, aeration and GAC absorption may introduce possible infectious
particulates into the treated water. Thus, disinfection is generally required as a post-treatment
when radon reduction technologies are installed.
When only low removal efficiency is required, and sufficient capacity is available, simple
storage may in some cases be sufficient to reduce radon levels in water below specified radon
levels. Radon levels rapidly decrease through natural radioactive decay, and if storage is in
contact with air, through volatilization. Therefore, storage has also been included in the cost
analysis.
46
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In some cases, water systems will choose to seek other sources of water rather than
employ expensive treatment technologies. Systems may choose a number of strategies, such as
shutting down sources with high radon levels and pumping more from sources with low levels, or
converting from ground water to surface water. In the cost analysis, however, it has been
assumed that such options will not be available to most systems, and they will need to obtain
water from other systems. This option is referred to as "regionalization" in the following
discussions.
These general families of technologies, along with the specific variants used in the cost
analysis, are described.
5.1.1 Aeration
Because of radon's volatility, when water containing radon comes into contact with air,
the radon rapidly diffuses into the gas phase. Several aeration technologies are available. As
will be discussed in more detail below, the specific technology adopted in response to the rule
will depend on the system's influent radon level, size, and the degree of radon removal that is
required. The following common aeration technologies have been included in this analysis.
Other aeration technologies are available (spray aeration, tray aeration, etc.) that can potentially
be used by water systems to remove radon. These technologies have not been included in the
analysis either because they have technical characteristics that limit their use in public water
systems, or because their removal efficiencies are lower, and/or their unit costs are higher than
the three aeration technologies included in the analysis.
Packed Tower Aeration (PTA). During PTA treatment, the water flows downward by
gravity and air is forced upward through a packing material that is designed to promote intimate
air-water contact. The untreated water is usually distributed on the top of the packing with sprays
or distribution trays and the air is blown up a column by forced or induced draft. This design
results in continuous and thorough contact of the liquid with, air (US EPA 1998O). In terms of
radon removal, PTA is the most effective aeration technology. Radon removal efficiencies of up
to 99.9 percent are technically feasible and not prohibitively expensive for most applications. In
this analysis, two different PTA treatments are used to estimate radon removal cost. The costs
are dependant on the degree of reduction required to achieve compliance with the allowable
radon level. The first design is capable of reducing radon levels by 80 percent; the second and
more costly version reduces radon in drinking water by 99 percent.
Diffused Bubble Aeration (DA). Aeration is accomplished in the diffused-air type
equipment by injecting bubbles of air into the water by means of submerged diffusers or porous
plates. The untreated water enters the top of the basin and exits from the bottom [having been]
treated, while the fresh air is blown from the bottom and is exhausted from the top (US EPA
1998O). Diffused bubble aeration can achieve radon removal efficiencies greater than 90
percent. In this analysis, a DA system with a removal efficiency of 80 percent is used as the
basis for estimating compliance costs.
47
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Multiple Stage Bubble Aeration flvISBAX MSB A is a variant of DA developed for small
to medium water supply systems (US EPA 1998O). MSBA units consist of shallow, partitioned
trays. Water passes through multiple stages of bubble aeration of relatively shallow depth. In
this analysis, an MSBA radon removal efficiency of 80 percent is assumed.
All of the aeration technologies discussed above are assumed to be "central" treatments in
the cost analysis. That is, a single large installation is used to treat water from a given source,
prior to the water entering the distribution system to serve many users. It is also technically
feasible to apply some of these technologies at the point of entry (e.g. just before water from the
distribution system enters the household where it is to be used). However, most aeration
technologies are only cost-effective at minimum flows far above that corresponding to the water
usage rate of a typical household, and thus would not likely be selected as the treatment of
choice.
Also, in all of the aeration systems just discussed, the radon removed from water is
released to ambient (outdoor) air. In this analysis, it has been assumed that the air released from
aeration systems will not itself require treatment, result in appreciable risks to public health, or
result in increased permitting costs for water systems. For the 1991 proposed rule, EPA
conducted analyses on radon emissions and potential risks associated with radon and its progeny
as they disperse from a water treatment facility (US EPA 1988, 1989). In summary, these
analyses concluded that the annual risk of fatal cancer from radon and its progeny in off-gas
emissions was 2700 times smaller (108 cases/0.04 cases) than the annual risk of fatal cancer from
radon and its progeny from tap water after all ground water systems were at or below the 1991
target level of 300 pCi/L. Using the occurrence estimates at that time, the off-gas risk was
estimated to be 4800 times smaller (192 cases/0.04 cases) than the radon in tap water risk if no
water mitigation was done (US EPA 1994C). The EPA's SAB reviewed the Agency's report and
concluded that: (1) while the uncertainty analysis could be upgraded to lend greater scientific
credibility, the results of modeling would not likely change, i.e., the risk posed by release of
radon through treatment would be less than that posed by drinking untreated water; and (2) it is
likely that the conservative assumptions adopted by EPA in its air emissions modeling resulted in
overestimates of risk (US EPA 1994C).
5.1.2 Granular Activated Carbon (GAC)
The second major category of radon removal technology is treatment with granular
activated carbon. GAC adsorption removes contaminants from water by the attraction and
accumulation of the contaminant on the surface of carbon. The magnitude of the available
surface area for adsorption to occur is of primary importance, while other chemical and
electrochemical forces are of secondary significance. Therefore, high surface area is an
important factor in the adsorption process (US EPA 1998O). GAC systems are commonly used
in water supply systems to remove pesticides or other low-volatility organic chemicals that
cannot be removed by aeration. Radon can also be captured by GAC filtration, but the amounts
of carbon and the contact times needed to produce a high degree of radon removal are generally
much greater than those required to remove common organic contaminants. For most system
48
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sizes and design configurations evaluated in this study, aeration can achieve the same degree of
radon reduction at lower cost than GAC. However, in the cost analysis for the radon rule, it has
been assumed that a small minority of systems will nonetheless choose GAC technology over
aeration alternatives, due to system-specific needs (e.g., land availability). Also, POE GAC (see
below) may be cost-effective for systems serving only a few households. Depending on the
specific design and operating characteristics, GAC can remove up to 99.9 percent of influent
radon, but high removal efficiencies require large amounts of carbon and long contact times.
Two types of GAC systems have been evaluated: Central GAC and Point of Entry GAC
(POE GAC). Central GAC refers to a design configuration in which the activated carbon
treatment takes place at a central treatment facility, prior to entry into the distribution system.
GAC may be combined with other treatments and may be used to remove contaminants other
than radon in large, centralized facilities. In this analysis, costs are estimated for central GAC
systems with removal rates of 50, 80, and 99 percent. POE GAC generally refers to small- to
medium-sized carbon filtration units placed in the water distribution system just before use
occurs (e.g., before water enters a residence from the distribution system.) System maintenance
involves periodic replacement of the filter units. As noted previously, POE GAC may be the
most cost-effective treatment for very small systems serving few households. Costs are
estimated for POE GAC with removal rates of 99%.
5.1.3 Storage
Another technology that may be practical when only a relatively slight reductions in radon
levels are needed is the storage of water for a period of time necessary for radioactive decay and
volatilization to reduce radon to acceptable levels. Depending on the configuration of the vessel,
storage for 24 to 48 hours may be sufficient to reduce radon levels by 50 percent or more. The
mode of removal is a combination of radon decay and transfer of the radon from the water to the
storage tank headspace, which is refreshed through ventilation (US EPA, 1998D). It has been
assumed that a proportion of the smallest CWSs (serving 500 people or fewer) with relatively
low influent radon levels and sufficient storage capacity may choose storage as the preferred
radon treatment technology. In estimating costs for the storage option, it is assumed that the
entire capital and O&M costs of the storage system is attributable to the need to reduce radon
levels. In fact, the majority of CWSs choosing storage are likely to already have at least some
storage capacity available (ten percent of small systems have atmospheric storage in place (US
EPA 1997A)). These systems may be able to add ventilation and/or other mechanisms to
increase air/water contact with a small capital investment, which supports the conclusion that the
present assumption of no storage in place is a conservative assumption.
5.1.4 Regionalization
The last technology whose costs are included in the HRRCA is regionalization. In this
analysis, regionalization is defined as the construction of new mains to the nearest system with
water below the required radon level. This cost is estimated to be $280,000 per system (1997$).
The cost of actually purchasing water is not included in regionalization costs, for several reasons.
49
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In the first case, regionalization may involve the actual consolidation of water systems, and thus
there may be no charge to the system which is "regionalized". In addition, the system which
supplies the water to the regionalized system will still incur the same (or nearly the same) costs
for radon treatment as before regionalization and could be expected to pass them on to the
regionalized system. This assumes that the water production cost ($/kgal) for the CWS before it
regionalizes is equal to the unit price ($/kgal) it will pay to the water system from which it
purchases water. In reality, this will over-estimate costs in some cases and under-estimate in
others. Including a water purchase price in the cost estimate for regionalization without
correcting it for the removal of water production costs would lead to an over-estimate in the costs
of regionalization.
5.1.5 Radon Removal Efficiencies
The amount of radon that the various technologies can remove from water varies
according to their specific design and operating characteristics. At the most costly extreme, both
aeration and GAC technologies can remove 99 percent or more of the radon in water. Less costly
alternative designs remove less radon. In this analysis, one or more cost estimates have been
developed for the technologies discussed above, corresponding to one or more radon removal
levels. Approximate cost ranges for achieving specified radon reduction efficiencies using the
various technologies are shown in Table 5-1. These costs are estimated based on flow rates for a
single installation, which may treat water for an entire system or from a single source. For the
aeration and GAC technologies, costs have also been derived for combined radon removal and
post-treatment technologies, as discussed below. The basis for the derivation of these cost
estimates is described in more detail in Section 5.4.
The procedures used to decide what proportion of CWSs will adopt the various radon
removal technologies is described in more detail in Section 5.5. In general, however, the large
majority of the systems are assumed to select the least-cost technology required to achieve a
target radon level. Other systems, for reasons of technical feasibility, may need to choose more
costly treatment technologies.
5.1.6 Pre-Treatment to Reduce Iron and Manganese Levels
Pre-treatment technologies may also need to be part of radon reduction systems. Aeration
and GAC technologies can be fouled by high concentrations of iron and manganese (Fe/Mn).
EPA believes that Fe/Mn concentrations greater than 0.3 mg/1 would generally require
pretreatment to protect aeration/GAC systems from fouling. However, since this level is near to
the secondary MCL, it is believed that essentially all systems with iron and manganese levels
above 0.3 are likely to already be treating to remove or sequester these metals. Therefore, costs of
adding Fe/Mn treatment to radon removal systems are not included in the HRRCA. Preliminary
EPA estimates suggest that inclusion of Fe/Mn treatment costs will not significantly effect overall
cost estimates for radon removal. More detailed analysis will be presented when the proposed
NPDWR is published.
50
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Table 5-1. Unit Treatment Costs by Removal Efficiency and System Size
Treatment
Technology
Train for
Radon in
Water1
Radon
Removal
Efficiency
(% radon
removed)
Size Category (Population
Served)=>
PTA/MSBA/STA
PTA/MSBA/STA
+ chlorination
DA
DA + chlorination
Central GAC
Central GAC +
chlorination
Ventilated
Storage3
POE GAC
80
99
80
99
80
80
50
80
99
50
80
99
50
99
Annual Operations and Maintenance
Cost (S/kgal)
25-
100
0.76
0.85
2.17
2.26
0.66
2.08
7.36
7.52
98.39
8.77
8.93
99.80
1.41
NA
101-
soo
0.22
0.26
0.61
0.64
0.32
0.71
2.39
2.54
51.26
2.78
2.92
51.67
0.38
NA
500-
3.3 K
0.07
0.09
0.24
0.26
0.22
0.39
0.54
0.65
24.77
0.71
0.82
24.94
0.17
NA
3.3 K
-10K
0.04
0.05
0.10
0.12
0.19
0.26
NA
NA
NA
NA
>10K
tf/kgal)
2-4
4-5
3-10
5-12
NA2
NA
NA
NA
NA
NA
Annualized Capital Cost (Debt cost @
7% over 20 years) ($/kgal)
25-100
1.51
1.91
1.89
2.29
0.71
1.09
14.48
18.64
23.81
14.86
19.02
24.20
1.90
NA
101-
500
0.64
0.81
0.74
0.91
0.40
0.49
6.11
7.65
10.44
6.21
7.74
10.54
0.84
NA
500-
3.3 K
0.21
0.27
0.28
0.34
0.26
0.34
2.17
2.98
6.64
2.24
3.05
6.71
0.43
NA
3.3 K
-10K
0.08
0.14
0.10
0.16
0.23
0.24
NA
NA
NA
NA
>10K
tf/kgal)
4-8
6-14
4-10
7-16
NA
NA
NA
NA
NA
NA
Total Annual Costs (S/kgal)
25-
100
2.27
2.75
4.07
4.55
1.37
3.17
21.83
26.15
122
23.63
27.95
124
3.31
10.00
101-
500
0.87
1.07
1.35
1.55
0.72
1.20
8.50
10.19
61.72
8.98
10.67
62.20
1.22
10.00
500-
3.3 K
0.28
0.36
0.52
0.60
0.48
0.72
2.71
3.63
31.40
2.95
3.87
31.65
0.60
9.00
3.3 K
-10K
0.12
0.19
0.20
0.27
0.42
0.50
NA
NA
NA
NA
>10K
tf/kgal)
6-12
11-19
7-20
12-27
NA
NA
NA
NA
NA
NA
1 PTA = packed tower aeration, STA = shallow tray aeration, MSBA = multi-stage bubble aeration, DA = diffused aeration, GAC = granular activated
carbon, POE = point-of-entry.
2 If "NA" appears in a column, it signifies that this technology was not used in the decision tree for that size category.
3 O&M Costs for storage are assumed to be identical to chorination O&M costs.
51
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5.1.7 Post-Treatment-Disinfection
In addition to pre-treatment requirements, the installation of some radon reduction
technology may also require post-treatment, primarily to reduce microbial contamination. Both
aeration and GAG treatment may introduce potentially infectious particulate contamination, which
must be addressed before the water can enter the distribution system. The treatment of water for
other contaminants may also introduce microbial contamination. This is one reason why the
majority of systems already use disinfection technologies. As will be discussed in more detail
below, a substantial proportion of ground water systems (ranging from 50 percent in the smallest
size category, to about 68 percent of the largest systems) already disinfect. Costs of disinfection
are only attributed to the radon rule only for that proportion of systems not already having
disinfection systems in place. For systems that do not already disinfect, chlorination is assumed to
be the treatment of choice. Alternative technologies are available, for example UV disinfection,
but chlorination is widely used in all size classes of water supply systems, and the chlorination is
considered to provide a reasonable basis for estimating disinfection costs.
5.2 Monitoring Costs
While not strictly speaking a water treatment technology, ground water monitoring will
play an important role in any strategy to reduce radon exposures. Therefore, monitoring costs
have been included as a cost element in the cost analysis.
Although EPA has not yet defined a monitoring strategy for the proposed NPDWR, it is clear that
systems will, first, have to sample influent water to determine the need for treatment, and second,
continue to monitor after treatment (or after a decision is made not to mitigate). For the purpose
of developing national cost estimates, it has been assumed that all systems will have to conduct
initial quarterly monitoring of all sources, and continue to conduct radon monitoring and analysis
indefinitely after the rule is implemented. This is a conservative assumption (likely to overstate
monitoring costs) because in reality a large proportion of systems with radon levels below the
MCL will probably be allowed to monitor less frequently after the initial monitoring period.
Monitoring costs are simply the unit costs of radon analyses times the number of samples
analyzed. The number of intake sites per system is estimated from SDWIS data, as discussed in
Section 5.7. The cost of analyzing each sample is estimated to be between $40 and $75, with an
representative cost of $50 per sample used for the national cost estimate (US EPA 1998K).
5.3 Water Treatment Technologies Currently In Use
EPA has conducted an extensive analysis of water treatment technologies currently in use
by ground water supply systems (Table 5-2). This table shows the proportions of ground water
systems with specific technologies already in place broken down by system size (population
served). Many ground water systems currently employ disinfection, aeration, or Fe/Mn removal
technologies. This distribution of pre-existing technologies serves as the baseline against which
water treatment costs are measured. For example, costs of disinfection are attributed to the radon
rule only for the estimated proportion of systems that would have to install disinfection as a post-
52
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treatment because they do not already disinfect.
Within current EPA cost models, the estimate of the number of sites (entry points into the
distribution system) is ideally broken down into three parts: estimates of the average national
occurrence of the contaminant in drinking water systems, the intra-system variability of the
contaminant concentration, and the typical number of sites within system size categories. In prior
RIAs, EPA modeled all drinking water systems requiring treatment as installing centralized
treatment, which assumes that there is one point of treatment within a system. A more accurate
estimate of treatment would be to calculate costs according to treatment installed at each well site
that is predicted to be above the target radon level within a water system. This intra-system
variability analysis accounts for the fact that, in reality, multi-site water systems do not necessarily
have the same radon level at each site. However, because the analysis of intra-system variability
for radon occurrence is not yet complete, it is not possible to use this approach to calculate
treatment costs. For future rules, including the proposed rule for radon, EPA will calculate
national cost estimates based on the number of sites rather than by the system as a whole. These
estimates will more accurately reflect the percentage of the population receiving drinking water
that has been treated in some way and will result in more accurate national compliance cost
estimates.
The cost analysis assumes that any system affected by the rule will continue to employ
pre-existing radon treatment technology and pre- and post-treatments in their efforts to comply
with the rule. Where pre- or post-treatments are already in place, but radon treatment is currently
not taking place, it is assumed that compliance with the radon rule will not require any upgrade or
change in the pre- or post-treatments. Therefore, no incremental cost is attributed to pre- or post-
treatment technologies. This may underestimate costs if pre- or post-treatments need to be
changed (e.g., a need for additional chlorination after the installation of packed tower aeration).
The potential magnitude of this cost underestimation is not known, but is likely to be a very small
fraction of total treatment costs.
53
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Table 5-2. Estimated Proportions of Ground water Systems With Water Treatment
Technologies Already in Place (Percent)1
Water Treatment
Technologies in Place
Fe/Mn Removal &
Aeration & Disinfection
Fe/Mn Removal &
Aeration
Fe/Mn Removal &
Disinfection
Fe/Mn Removal
Aeration & Disinfection
Only
Aeration Only
Disinfection Only
None
System Size (Population Served)
25-
100
0.4
0.0
2.1
1.9
0.9
0.8
49.6
44.3
101-
500
0.2
0.1
5.1
1.5
3.2
1.0
68.2
20.7
501-
1K
1.2
0.2
8.3
1.5
9.8
1.8
65.0
12.2
1K-
3.3K
0.6
0.1
3.0
1.0
13.7
2.9
65.0
13.7
3.3K-
10K
2.9
0.4
7.8
1.1
20.9
2.9
56.3
7.7
10K-
50K
2.2
0.1
7.4
0.4
19.7
1.0
66.0
3.2
50K-
100K
3.1
0.4
9.7
1.1
18.6
2.1
58.3
6.7
100K-
1M
2.0
0.1
6.8
0.2
19.9
0.6
68.3
2.1
Notes: 1. Source: EPA analysis of data from the Community Water System Survey (CWSS), 1997, and Safe
Drinking Water Information System (SDWIS), 1998.
5.4 Cost of Technologies as a Function of Flow Rates and Radon Removal Efficiency
EPA has developed a set of cost curves that describe the relationships between the capital
and operating and maintenance costs of the various treatment technologies, flow rates, and the
degree of radon removal that is required (US EPA 1998A, 1998O). Cost curves were developed
using the most recent available data and standard cost estimation methodologies. Separate
functions for capital and operation and maintenance (O&M) costs have been developed for each
technology and radon removal rate. For all of the technologies except regionalization, both the
capital and O&M cost curves are functions of flow rates. Capital costs are estimated as a function
of the design flow (DF) of the technology. The DF for a technology is equal to a technology's
maximum flow capacity, or the largest amount of water that can be processed per unit time. The
DF is typically two to three times greater than the average amount of water treated by a given
system. O&M costs are functions of the average flow (AF) through the system. Labor, treatment
chemicals and materials, periodic structure maintenance, and water stewardship expenses are
estimated based on daily average flows. The cost curves developed by OGWDW for the various
radon removal technologies are provided in Appendix B.
54
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5.5 Choice of Treatment Responses
The Agency has developed a set of assumptions regarding the choices that CWSs will
make in deciding how to mitigate water radon levels to meet specific exposure reduction
requirements. These assumptions have been developed taking into account the expected influent
radon levels, the degree of radon removal needed to reach specified levels, the types of
technologies that would be technically feasible and cost-effective for systems of a given size, and
the distribution of pre-existing technologies shown in Table 5-2. Generally, it is assumed that a
system will choose the least-cost alternative technology to achieve a given radon level. For
example, to achieve a radon level of 100 pCi/1, all systems with average influent levels below 100
would not need to mitigate, systems with influent radon levels between 100 and 200 pCi/1 would
need to employ technologies that achieve 50 percent reduction, systems with influent levels
between 200 and 500 pCi/1 would employ technologies capable of 80 percent radon removal, and
systems with influent radon above 500 pCi would employ technologies with removal efficiencies
of 99 percent. In actuality, removal efficiencies would be more variable; e.g., a removal
efficiency of 90 percent, rather than 99 percent, could be employed for radon levels between 500
and 1,000 pCi/1. However, this cost analysis has been limited to three removal efficiencies to
simplify the analysis. EPA does not believe that this has introduced any significant bias into the
assessment.
Table 5-3 presents the estimated proportions of systems of given sizes that are expected to
choose specified radon reduction technologies for given degrees of radon removal. Most systems
in most size classes are assumed to choose aeration as the preferred radon reduction technology
with or without disinfection, depending on the proportion of systems in that size stratum already
disinfecting. This is because some form of aeration is generally the most cost-effective option for
a given degree of radon reduction. For small systems and low required removal efficiencies,
multistage fixed-bed (MSBA) and diffused bubble aeration (DA) tend to be the most cost-
effective. For large systems and high removal efficiencies, packed tower aeration (PTA) is the
only feasible aeration technology.
Small proportions of the smallest system size categories (less than 5 percent in all cases)
are assumed to choose central GAC with or without disinfection. A few percent of the smallest
systems are also assumed to choose POE GAC. Storage is assumed to be a viable option for two
percent of small systems where radon reduction of 50 percent or less is required, and
regionalization is assumed to be feasible for one percent of the smallest systems. EPA has
assumed in this HRRCA that no systems would choose spray aeration or alternative source
technologies. It is believed that these technologies would be chosen only rarely, and their
omission has not biased the compliance cost estimates. This issue will be addressed in more
detail hi the proposed NPDWR.
55
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Table 5-3. Decision Matrix for Selection of Treatment Technology Options: Up to 50 Percent Removal
TreatmentTechnology Option
»TA (80)
»TA (80) + disinfection
MSBA/STA (80)
MSBA/STA (80) + disinfection
)A (80)
)A (80) + disinfection
Retrofit Spray
iAC (50)
iAC (50) + disinfection
»OE GAC (99)
> to rage (50)
legionalization (99)
\lternate source (99)
\1I Systems
Percent of System Size Category (Population Served) Choosing Treatment Technology
<100
2.6
2.4
13.2
11.8
31.7
28.3
0.0
2.6
2.4
2.0
2.0
1.0
0.0
100
101-500
7.8
2.2
21.8
6.2
43.4
12.6
0.0
2.3
0.7
0.0
2.0
1.0
0.0
100
501-1000J
16.8
3.2
22.7
4.3
42.7
8.3
0.0
0.8
0.2
0.0
1.0
0.0
0.0
100
1001-3.3K
31.9
8.1
15.9
4.1
31.9
8.1
0.0
0.0
0.0
0.0
0.0
0.0
0.0
100
3301-10K
60.8
9.2
8.7
1.3
17.4
2.6
0.0
0.0
0.0
0.0
0.0
0.0
0.0
100
10-50K
86.9
3.2
0.0
0.0
9.7
0.4
0.0
0.0
0.0
0.0
0.0
0.0
0.0
100
50-1 OOK
86.3
13.7
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
100
100-1000K
96.4
3.6
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
100
56
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Table 5-3. (Continued) Decision Matrix For Selection of Treatment Technology Options: 50 to 80 Percent Removal
TreatmentTechnology Option
»TA (80)
>TA (80) + disinfection
MSBA/STA (80)
MSBA/STA (80) + disinfection
)A (80)
)A (80) + disinfection
Retrofit Spray
JAC (80)
SAC (80) + disinfection
*OE GAC (99)
legionalization (99)
Alternate source (99)
\H Svstems
Percent of System Size Category (Population Served) Choosing Treatment Technolo
<100
4.2
3.8
14.8
13.2
29.6
26.4
0.0
2.6
2.4
2.0
1.0
0.0
100
101=500
10.9
3.1
21.0
6.0
42.8
12.2
0.0
2.3
0.7
0.0
1.0
0.0
100
501-1000
20.2
3.8
21.0
4.0
42.0
8.0
0.0
0.8
0.2
0.0
0.0
0.0
100
1D01-3 3K
31.9
8.1
15.9
4.1
31.9
8.1
0.0
0.0
0.0
0.0
0.0
0,0
100
1301-10K.
60.8
9.2
8.7
1.3
17.4
2.6
0.0
0.0
0.0
0.0
0.0
0.0
100
1 0-50 K
96.5
3.5
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
100
50-1 OOK
86.3
13.7
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
100
gy
100-1000K
96.4
3.6
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
100
57
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Table 5-3. (Continued) Decision Matrix For Selection of Treatment Technology Options: 80 to 99 Percent Removal
TreatmentTechnology Option
»TA (99)
»TA (99) + disinfection
VISBA/STA (99)
MSBA/STA (99) + disinfection
5AC (99)
JAC (99) + disinfection
»OE GAC (99)
legionalization (99)
Alternate source (99)
TOTALS
Percent of System Size Category (Population Served) Choosing Treatment Technology
<100
15.3
13.7
34.3
30.7
1.6
1.4
2.0
1.0
0.0
100
101 500
26.5
7.5
49.1
13.9
1.6
0.4
0.0
1.0
0.0
100
501 1000 1 100 1 3 3K.
35.3
6.7
48.7
9.3
0.0
0.0
0.0
0.0
0.0
100
47.8
12.2
31.9
8.1
0.0
0.0
0.0
0.0
0.0
100^
1301 10K
69.4
10.6
17.4
2.6
0.0
0.0
0.0
0.0
0.0
100
10 -50 K
96.5
3.5
0.0
0.0
0.0
0.0
0.0
0.0
0.0
100
50-1 OOK
86.3
13.7
0.0
0.0
0.0
0.0
0.0
0.0
0.0
100
100-1000K
96.4
3.6
0.0
0.0
0.0
0.0
0.0
0.0
0.0
100
Notes:
1. Technology abbreviations: PTA = packed tower aeration, MSBA/STA = multi-stage bubble aeration, GAC = granular activated carbon, POE GAC = point of
entry granular activated carbon. Numbers in parentheses indicate removal efficiencies.
2. Capital costs for small systems include land costs. For large systems, it is assumed that additional land is not required.
3. Sequestration costs are included in PTA and MSBA/STA capital costs.
4. Additional housing costs are included in PTA, MSBA/STA, and GAC capital costs and are weighted under the assumption that 50% of small systems will
require additional housing, 100% of large systems will require additional housing
5. Permitting costs are included and are assumed to be 3% of capital costs, with a minimum of $2500.
6. Pump and blower redundancies are included in capital costs.
58
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5.6 Cost Estimation
5.6.1 Site and System Costs
The costs of reducing radon in ground water to specific radon levels was calculated using
the cost curves discussed in Section 5.4 and the matrix of treatment options presented in Section
5.5. For each radon level and system size stratum, the number of systems required to reduce
radon levels by up to 50 percent, 80 percent and 99 percent were calculated. Then, the cost curves
for the distributions of technologies dictated by the treatment matrix were applied to the
appropriate proportions of the systems. Capital and O&M costs were then calculated for each
system, based on typical estimated design and average flow rates. These flow rates were
calculated on spreadsheets using equations from EPA's Safe Drinking Water Suite Model (US
EPA 1998N). The equations and parameter values relating system size to flow rates are presented
in Appendix C.
The distributions of influent radon levels in the various system size categories were
calculated using the results of EPA's updated radon occurrence analysis (exceedance proportions
calculated from data in US EPA 1998L).
Capital and O&M costs were estimated separately for each "site" (a separate water source,
usually a well) within systems. Where systems obtained water from only one site, costs are
calculated by applying the entire system flow rate to the appropriate cost curves. Where systems
consisted of more than one site, the total system flow rate was divided by the number of sites,
capital and O&M costs were then calculated for the resulting flow rate, and the total system cost
was obtained by multiplying this result by the number of sites in the system. This approach
provides conservative cost estimates, because it assumes that separate treatment systems would be
built at each site. This approach also obscures some of the effects of variability in system sizes on
costs, because each system in a given size category is assumed to have the same flow rate.
Table 5-4 summarizes the numbers of sites per system for the various size categories of
combined public and private community ground water systems. The average ranges from 1.1 site
per system serving less than 100 people to almost nine sites per system serving greater than
100,000 people. The distributions of the numbers of sites per systems are very skewed, with
ninetieth-percentile values ranging from 2 to 20 sites per system for the smallest and largest size
categories, respectively. A large proportion of the systems serving 10,000 people or less obtain
water from only one site. Public and private water systems differ with regard to system design
and average flows. For this reason, separate cost estimates have been developed for the public
and private community ground water systems.
59
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Table 5-4. Numbers of Sites per Ground Water System by System Size
System Size (Population
Served)
25-100
101-500
501-1,000
1,001-3300
3,301-10,000
10,001-50,000
50,000-100,000
>100,000
Average Sites per System
1.1
1.2
1.4
1.7
2.3
3.9
8.7
8.8
90th Percentile Sites per
System
2
2
3
4
4
10
20
20
Source: EPA analysis of CWSS data, 1998.
In addition to the costs of radon treatment and disinfection, monitoring costs were also
calculated for each system. As noted previously, the average cost of monitoring was estimated to
be $50 per sample, and it was assumed that each site in a system would need to be monitored
quarterly. Monitoring costs were added as an ongoing cost stream to the O&M costs.
5.6.2 Aggregated National Costs
The estimated costs of reducing radon levels to meet different radon levels were estimated
by summing the costs for the individual sites and systems in each size category and influent range.
Separate totals were compiled for capital and O&M costs. Capital costs were annualized (over
20 years at a seven per cent discount rate) and added to the annual O&M costs to provide single
aggregate estimates of national costs for each radon level. This approach implicitly assumes that
treatment devices have useful lives that are identical to the period of financing. In reality, the
useful life and period of financing are not necessarily the same. The aggregate cost estimates are
presented in Section 6. As will be discussed in more detail below, separate cost estimates were
developed for implementation options involving MMM programs and are presented in Section 7.
Summary outputs of the spreadsheet models used to estimate costs are provided in Appendix D.
5.6.3 Costs to Community Water Supply Systems
As noted above, costs were estimated separately for public and private ground water
systems. Costs per system were calculated by dividing total costs for a given size category of
public or private system by the total number of systems needing to mitigate radon. The results of
these assessments are presented in Section 6.
60
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5.6.4 Costs to Consumers/Households
Costs to households have also been calculated for public and private ground water
systems. Costs are calculated by multiplying the average annual treatment costs per thousand
gallons by the estimated average household consumption (83,000 gal/year). This approach
assumes that all water systems pass incremental costs attributable to the radon rule on to system's
residential customers and that the residential customers will pay the same proportion of costs as
other users. Average household costs are calculated separately for public and private community
water systems across various system-size categories. Per household costs are then compared to
median household income data (US EPA 1998H) for the same system-size categories. These
impacts are discussed in Section 6.
5.6.5 Costs of Radon Treatment by Non-Transient Non-Community Systems
Very little data are available that will support the development of detailed estimates of
radon treatment costs for the NTNCWS that could be affected by a radon NPDWR. EPA is
currently conducting a more detailed evaluation of the characteristics of NTNCWSs that will be
completed in time for the proposed rule.
5.7 Application of Radon Related Costs to Other Rules
The baseline for the radon rule compliance cost estimates presented in this draft HRRCA
consists of the pre-existing treatment technology distribution shown in Table 5-2. As the radon
rule is implemented, however, other rules may also require additional systems to install new
technologies (e.g., disinfection). Thus, attributing all costs of increased use of disinfection at
systems with high radon levels to the radon rule would overstate its cost. At the present time,
EPA has not quantified the potential degree to which the costs of the radon rule may be
overstated.
6. RESULTS: COSTS AND BENEFITS OF REDUCING RADON IN DRINKING WATER
This section presents benefit, cost, and impact estimates for the various radon levels.
Section 6.1 provides an overview of the analytical approach. Sections 6.2 and 6.3 present the
monetized benefit and cost estimates for the various radon levels evaluated. Section 6.3
summarizes the economic impacts on the various affected entities. Section 6.5 compares the costs
and benefits of the radon levels evaluated. Section 6.6 presents a brief summary of the major
uncertainties in the cost, benefit, and impact estimates.
The presentation of costs and benefits in this Section is based on analysis of radon levels
of 100, 300, 500, 700, 1,000,2,000, and 4,000 pCi/1 in CWSs served by ground water.
6.1 Overview of Analytical Approach
The analysis of benefits quantifies the reduction in health risks/impacts to the general
61
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population and considers the risks to potentially sensitive subpopulations (qualitatively). The
evaluated health benefits of the rule consist of reduced fatal and non-fatal cancer risks, and the
monetary surrogates for these benefits have been estimated, as described in Section 4.0. The
national cost estimates developed include the capital and O&M costs to reduce radon, along with
pre- and post-treatment costs where appropriate, as well as monitoring costs. Record keeping and
reporting costs and implementation costs to States and government entities will be addressed in
the RIA prepared for the proposed rule.
The costs and benefits of a radon NPDWR will result in economic impacts on affected
individuals, corporate entities, and government entities. In this analysis, the impacts on water
systems and households have been evaluated. These include: (1) the cost to systems of different
sizes and ownership types, and (2) changes in water costs to households as a proportion of
income. Public systems include those owned by government entities. Private systems consist of
investor-owned entities that provide drinking water as their primary line of business. Ancillary
systems include drinking water systems that are operated incidentally to another business. The
vast majority of ancillary systems are mobile home parks, but some are schools, hospitals, and
other entities. The economic impacts of the MMM programs on systems or households have not
been calculated, because there is no information at present as to how these programs would be
funded or upon whom the costs would fall.
6.2 Health Risk Reduction and Monetized Health Benefits
The probabilistic risk model was used to calculate the cancer risk reduction benefits of the
various levels. Risk reduction benefits were calculated by subtracting the estimated population
risk (number of fatal cancers per year at a particular radon level) from the baseline (pre-
regulation) population cancer risk due to radon exposure. Estimates of the number of non-fatal
cancers avoided were developed as described in Section 4.2.1. The results of this analysis are
summarized in Table 6-1. Under the baseline scenario, the estimated number of fatal cancers per
year caused by radon exposures in domestic water supplies is 160, and the number of non-fatal
cancers is 9.2. As radon levels decrease, residual risks decrease, and the risk reduction benefits
increase. Since very few people are exposed at levels above 2,000 pCi/1, the benefit of controls in
this range is relatively small (fewer than 7 cancers prevented per year). The health risk reduction
benefits then increase rapidly as radon levels decrease because progressively larger populations
are affected as more and more systems are required to mitigate exposures.
62
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Table 6-1. Residual Cancer Risk and Risk Reduction from
Reducing Radon in Drinking Water
Radon
Level (pCi/1
in water)
(Baseline)
4,000*
2,000
1,000
700
500
300
100
Residual Fatal
Cancer Risk
(Cases per
Year)
160
158
153
143
135
124
101
44.8
Residual Non-Fatal
Cancer Risk
(Cases per Year)
9.2
9.1
8.8
8.2
7.8
7.1
5.8
2.6
Risk Reduction
(Fatal Cancers
Avoided per Year)1
0
2.2
6.5
16
25
36
58
115
Risk Reduction
(Non-Fatal Cancers
Avoided per Year)1
0
0.1
0.4
0.9
1.4
2.1
3.4
6.6
Notes:
1. Risk reductions and residual risk estimates are slightly inconsistent due to rounding.
2.4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA provisions of Section 1412(b)(13).
At the lowest level (100 pCi/1) analyzed, the residual cancer risk (the cancer risk occurring
after controls are installed) is approximately 45 fatal cancers per year. The risk reduction from
this radon level is 115 fatalities per year, a reduction of approximately 72 percent from the
baseline of 160 per year. A similar proportional reduction in non-fatal cancers is seen with
decreasing radon levels.
The monetary valuation methods discussed in Section 4 were applied to these risk
reductions, as shown in Table 6-2. The central tendency benefits estimates are based on a VSL of
$5.8 million (1997$) and a WTP to avoid fatal cancers of $536,00 (1997$). The ranges of
benefits estimated using the upper and lower bound estimates of the VSL and WTP to avoid non-
fatal cancers are also provided in the table.
63
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Table 6-2. Estimated Monetized Health Benefits from Reducing Radon in Drinking Water
Radon Level
(pCi/1)
4,0003
2,000
1,000
700
500
300
100
Monetized Health Benefits,
Central Tendency
(Annualized, SMillions, 1997)'
13
38
96
145
212
343
671
Range of Monetized
Health Benefits
(Annualized, SMillions, 1997)2
2-35
5-106
12-268
18-403
26-591
43-955
84-1 87S
Notes:
1. Includes contributions from fatal and non-fatal cancers, estimated using central tendency estimates of the VSL of
$5.8 million (1997$), and a WTP to avoid non-fatal cancers of $536,000 (1997$).
2. Estimates the range of VSL between $0.7 and $16.3 million (1997$), and a range of WTP to avoid non-fatal
cancers between $169,000 (1997$) and $1.05 million (1997$).
3. 4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA provisions of Section 1412(b)(13).
Using central tendency estimates for each of the monetary equivalents, the baseline health
costs of fatal and non-fatal cancers associated with household radon exposures from CWSs are
estimated to be $933 million per year. Central tendency estimates of monetized benefits range
from $13 million per year for a level of 4,000 pCi/1 up to $673 million for the most stringent level
of 100 pCi/1. When different values for the VSL are used, the benefits estimates change
significantly. Using a lower bound VSL of $0.7 million, the benefits estimates are reduced
approximately 9-fold compared to the central tendency estimates. Using an upper bound VSL of
of $16.3 million increases the benefits estimates by approximately 3-fold relative to the central
tendency estimate. Variations in the estimated WTP to avoid non-fatal cancers affect benefit total
estimates only slightly (i.e., less than 1 percent), since non-fatal cancers represent a very small
proportion of estimated radon cancer cases.
A more detailed breakout of the risk reduction, monetized benefits estimates, and the total
cost per fatal cancer case avoided for ever-smokers and never-smokers is provided in Tables 6-3
and 6-4.
64
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Table 6-3. Risk Reduction and Monetized Benefits Estimates For Ever-Smokers1
Fatal Cancers Avoided Per Year
Non-Fatal Cancers Avoided Per
Year
Annual Monetized Health
Benefits (SMillions, 1997) -
Central Tendency
Annual Incremental Health
Benefits ($Millions/year) -
Central Tendency
Annual Cost Per Fatal Cancer
Avoided ($Millions, 1997)2
Radon Level, pCi/1
40003
1.7
0.1
10.2
10.2
7.0
2000
5.2
0.3
30.6
20.4
4.4
1000
13.2
0.8
j
77.1
46.5
3.7
700
19.9
1.1
115.8
38.7
3.7
500
29.2
1.7
170.0
54.2
3.7
300
47.1
2.7
274.7
104.7
4.0
100
92.5
5.2
539.3
264.6
4.3
Notes:
1. Risk reductions for ever- and never-smokers were estimated using the NAS unit risk estimates summarized in
Table 3-4, an ever-smoking prevalence of 58% males and 42% females, a central VSL estimate of $5.8 million
(1997$), and central WTP estimate to avoid non-fatal cancer of $536,000 (1997$).
2. Total cost estimates come from Table 6-5. The cost per fatal cancer case avoided is calculated by dividing the
estimates of fatal cancers avoided per year by the annualized mitigation costs for each population. For purposes of
this analysis, it was assumed that the mitigation costs (for both water and MMM programs) would be allocated
equally to smoking and non-smoking populations.
3.4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on the SDWA provisions of Section
65
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Table 6-4. Risk Reduction and Monetized Benefits Estimates for Never-Smokers
Fatal Cancers Avoided Per Year
Non-Fatal Cancers Avoided Per
Year
Annual Monetized Health Benefits
(SMillions, 1997) - Central
Tendency
Annual Incremental Health
Benefits ($Millions/year) - Central
Tendency
Annual Cost Per Fatal Cancer
Avoided (SMillions, 1997)
Radon Level, pCi/1
4000*
0.4
0.03
2.4
2.4
29.2
2000
1.3
0.09
7.4
5
18.3
1000
3.2
0.22
18.6
11.2
15.3
700
4.8
0.33
27.9
9.3
15.4
500
7.0
0.48
41.0
13.1
15.5
300
11.4
0.78
66.3
25.3
16.4
100
22.3
1.54
130.2
63.9
17.8
*4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section 1412(b)(13).
6.3 Costs of Radon Mitigation
This section describes the incremental costs associated with each of the radon levels.
Discussion of the cost results includes: the total nationally aggregated cost to all water systems
that must comply with the target radon levels. These include capital and O&M costs;
the average annualized cost per system exceeding the applicable radon level; the average
annualized costs per system and incremental costs per household, broken out by public and
private water system; and costs and impacts to households under each radon level. All costs are
incremental costs stated in 1997 dollars. Capital costs were annualized using a seven percent
discount rate and a 20-year amortization period.
6.3.1 Aggregate Costs of Water Treatment
The total annual nationally aggregated cost varies significantly by the specific radon
level. Total national cost estimates for CWSs are presented in Table 6-5. As demonstrated by the
exhibit, water mitigation costs increase substantially from the highest radon level analyzed ($24
million at 4000 pCi/1) to the lowest level analyzed ($795 million at 100 pCi/1).
66
-------
Table 6-5. Estimated Annualized National Costs of Reducing Radon Exposures
(SMillion, 1997)
Radon Level
(pCi/1)
4000*
2000
1000
700
500
300
100
Central Tendency
Estimate of Annualized
Costs
24
46
98
148
218
373
795
Range of Annualized
Costs (+/- 50%)
12-36
, 23-70
49-146
75-223
109-327
187-560
398-1193
Cost Per Fatal Cancer
Case Avoided
11.3
7.1
5.9
6.0
6.0
6.4
6.9
*4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section 1412(b)(13).
The costs borne by water systems are made up of annualized capital, O&M, and
monitoring costs. The contributions of these cost elements are broken out in Table 6-6. As the
radon level increases (i.e., is made less stringent), the proportion of costs due to monitoring
increases relative to capital and O&M costs.
Table 6-6. Capital and O&M Costs of Mitigating Radon
in Drinking Water (SMillion, 1997)
Radon Levels
(pCi/1)
4000*
2000
1000
700
500
300
Annual Capital
Cost
8.0
19.8
48.9
77.9
119
210
Annual O&M Cost
5.2
15.3
37.4
58.5
87.7
124
324
Annual Monitoring
Costs
11:4
11.4
11.4
11.4
11.4
11.4
11.4
Total Costs
25
46
98
148
218
373
795
*4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section
67
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6.4 Incremental Costs and Benefits of Radon Removal
Table 6-7 summarizes the central tendency and the upper and lower bound estimates of the
incremental costs and benefits of radon exposure reduction. Both the annual incremental costs
and benefits increase as the radon level is incrementally decreased from 2000 pCi/1 down to 100
pCi/1. The exhibit also illustrates the wide ranges of potential incremental costs and benefits due
to the uncertainty inherent in the estimates. Incremental costs and benefits are within 10 percent
of each other at radon levels of 1000,700, and 500 pCi/1. There is substantial overlap between the
incremental costs and benefits at each radon level.
Table 6-7. Estimates of the Annual Incremental Costs and Benefits of Reducing Radon in
Drinking Water (SMillions, 1997)
Annual
Incremental Cost
Range of Annual
Incremental Costs
Annual Incremental
Monetized Benefits
Range of
Incremental
Monetized Benefits
Incremental Cost Per
Fatal Cancer Case
Avoided
Radon Level, pCi/1
4000*
24
12-36
13
2-35
11.3
2,000
46
11-34
25
3-71
5.0
1,000
52
26-76
58
7-162
5.2
700
50
26-77
48
6-135
6.1
500
70
34-104
67
8-188
6.1
300
156
78-233
130
17-364
7.0
100
422
211-633
329
41-920
7.5
*4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section 1412(b)(13).
6.5 Costs to Community Water Systems
This section examines the regulatory costs that will be incurred by individual CWSs at the
various radon levels analyzed. Systems above the target radon level will incur monitoring costs
and treatment costs. Systems below the target radon level will incur only monitoring costs.
The number of CWSs exceeding the applicable radon level increases considerably with
each decrease in the radon level analyzed as shown Table 6-8. The table also shows that the vast
majority (90 percent or more) of affected systems, regardless of radon level, are very, very small
68
-------
(serving 25-500 people) or very small (serving 501-3,300 people).
Table 6-8. Number of Community Ground Water Systems
Exceeding Various Radon Levels
Exposure
Level
(pCi/1)
4000*
2000
1000
700
500
300
inn
ws
(25-100)
364
949
2149
3090
4201
6302
10.922
(101-500)
759
1448
2613
3459
4434
6233
10.349
VS
(501-
3.000^
60
205
668
1,153
1,796
3,059
6.077
S
(3,301-
lO.OOm
5
19
75
151
287
657
1.707
M
(10,000-
ioo.oo(n
i
8
44
94
177
387
995
L
(>100K)
0
0
2
5
9
19
48
Total
1,190
2,630
5,552
7,951
10,904
16,657
30Q9JL
Notes:
Source: (USEPA 19989L)
*4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section 1412(b)(13).
For CWSs that have radon in excess of a given level within each size category, the
average cost per system to reach the target level varies little as the radon levels decrease. This is
shown in Table 6-9, which presents the average annualized cost per public and private CWS by
system size category. This pattern is due in large part to the limited number of treatment options
assumed to be available to systems that may (in aggregate) be encountering a relatively wide range
of radon levels. In some cases (e.g., for very very small systems), the average cost per system for
a given system size increases as the radon level decreases. In other cases, the average cost per
system remains virtually constant as the radon level decreases. These inconsistent patterns are
due to two competing effects: (1) the average cost will tend to increase because some systems
must select a more costly treatment option; yet (2) the average cost will also tend to decrease with
the inclusion of previously unaffected systems (those with lower radon levels) that are most likely
to use lower-cost treatments. The cases where average costs decrease with decreasing radon
levels are due to the latter effect.
These results show that changing the radon level affects the number of CWSs that must
treat for radon, but generally does not significantly alter the cost per system for those systems
above the target level. Moreover, while large systems bear the greatest burden in terms of cost per
system, there are relatively few large systems with radon levels above the exposure scenarios
analyzed. The cost per system for CWSs with a radon concentration below a target radon level
will be the same because monitoring costs are dependent on system size and not on concentration.
Monitoring costs range from less than $250 for the very very small systems to almost $2,000 for
69
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large systems, again due to the larger number of sites requiring monitoring.
Table 6-9. Average Annual Cost Per System (SThousands, 1997)
Radon
Level
(pCi/1!
4000*
2000
1000
700
500
300
100
Public Systems Exceeding Radon Levels
vvs
(25-
100)
9
9
10
10
11
11
12
ws
(101-
500)
12
15
15
16
16
16
18
VS
28
28
28
28
28
28
28
s
68
68
68
68
68
68
68
M
184
186
186
184
185
184
184
L
1050
1055
1060
1062
1067
1084
1151
Private Systems Exceeding Radon
Levels
WS
(25-
100)
8
9
9
9
10
10
11
VVS
(101-
500)
10
12
13
13
13
13
15
VS
22
22
22
22
22
22
22
S
58
58
58
58
58
58
58
M
160
162
162
160
161
160
160
L
1014
1019
1023
1026
1030
1047
1110
Annual Per System Cost for those Systems BELOW each level: Monitoring Costs Only
]|_0.22
0.24
0.32
0.46
0.88
1.76
0.22
0.24
0.31
0.46
0.87
1.76
*4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements at Section 1412(b)(13).
6.6 Costs and Impacts to Households
This section reports incremental household costs and impacts associated with each radon
level, assuming that costs incurred by systems above the target radon levels are passed on to the
systems' customers (i.e., households). Costs per household reflects only monitoring and treatment
costs to CWSs above the target level. In addition, households served by CWSs falling under the
target radon level also will incur monitoring costs, but no treatment costs. Costs for these CWSs
are relatively low, however, and are not evaluated at the household level. As with per system
costs, the results are presented separately for public and for private CWSs. This is important in
considering impacts on households not only because the costs per system are different for public
versus private systems, but also because the smallest private systems tend to serve fewer
households than do the smallest public systems. Therefore, the average household served by a
private system must bear a greater percentage of the CWS's cost than does the average household
served by a public CWS. This is particularly important where capital costs make up a large
portion of total radon mitigation costs.
70
-------
The annual cost per household is presented in Table 6-10 for households served by public
and private CWSs. As expected, costs per household increase as system size decreases. Costs per
household is higher for households served by smaller systems than larger systems for two
reasons. First, smaller systems serve far fewer households than larger systems and, consequently,
each household must bear a greater percentage share of the CWS's costs. Second, smaller
systems tend to have higher influent radon concentrations that, on a per-capita or per-household
basis, require more expensive treatment methods (e.g., one that has an 85 percent removal
efficiency rather than 50 percent) to achieve the target radon level.
Another significant finding regarding annual cost per household is that, like the per-system
costs, household costs (which are a function of per system costs) are relatively constant across
different radon levels within each system size category. For example, there is less than $1 dollar
per year variation in cost per household, regardless of the radon level being considered for
households served by large public or private systems (between $6 and $7 per year), by medium
public or private systems (between $10 and $11 per year, and by small public or private systems
(between $19 and $20 per year). Similarly, for very small systems, the costs per household is
consistently about $34 per year for public systems and consistently about $40 per year for private
systems, varying little across radon level. Only for very very small systems is there a modest
variation in household costs. The range for per household costs for public systems serving 25-500
people is $87 per year (at 4000 pCi/1) to $135 per year (at 100 pCi/1). The corresponding range
for private systems is $139 to $238 per year. For households served by the smallest public system
(25-100 people), the range of cost per household ranges from $292 per year at 4000 pCi/1 to $398
per year at 100 pCi/1. For private systems, the range is $364 to $489 per year, respectively. Costs
per household for very very small systems differ more than do household costs for other system
size categories because very very small systems serve only between 25 and 500 people and,
consequently, serve fewer households. Therefore, even though per system costs show little
difference for any system size category, all system size categories (other than for very very small
systems) spread the small difference out among many more households such that the difference is
indistinguishable.
71
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Table 6-10. Annual Costs per Household for Community Water Systems ($, 1997)
ladon
level
(pCi/1)
4000*
2000
1000
700
500
300
100
Households Served by PUBLIC Systems
Above Radon level
WS
(25-100)
292
311
325
333
340
355
398
vvs
(101-500)
82
98
102
103
105
108
119
VS
34
34
34
34
34
34
34
S
19
19
19
19
19
19
19
M
10
11
11
10
10
10
10
L
6
6
6
6
6
6
7
Households Served by PRIVATE Systems
Above Radon level
vvs
(25-100)
364
387
403
. 412
421
439
489
VVS
(101-500)
105
127
132
134
136
141
155
VS
39
40
40
40
40
40
40
S
20
20
20
20
20
20
20
M
11
11
11
11
11
11
11
L
6
6
6
6
6
7
7
*4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section
To further evaluate the impacts of these household costs on the households that must bear
them, the costs per household were compared to median household income data for households in
each system-size category. The result of this calculation indicates a household's likely share of
incremental costs in terms of its household income. The analysis considers only households
served by CWSs with influent radon levels that are above the target radon level. Households
served by CWSs with lower radon levels may incur incremental costs due to new monitoring
requirements, but these costs are not significant at the household level.
Results are presented in Table 6-1 1 for public and private CWSs, respectively. For all
system sizes but one (very very small private systems), household costs as a percentage of median
household income are less than one percent. Impacts exceed one percent only for households
served by very very small private systems, which are expected to face impacts of just under 1.1
percent. Similar to the cost per household results on which they are based, household impacts
exhibit little variability across radon levels.
72
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Table 6-11. Per Household Impact by Community Ground Water Systems as a
Percentage of Median Household Income
Radon
level
(pCi/1)
4000*
2000
1000
700
500
300
100
Household Impact for Public Systems Above
Radon Level
(percent of median household income)
WS
25-100
0.86
0.92
0.96
0.98
1.00
1.05
1.17
WS
101-500
0.30
0.36
0.38
0.38
0.39
0.40
0.44
vs
0.13
0.13
0.13
0.13
0.13
0.13
0.13
S
0.06
0.06
0.06
0.06
0.06
0.06
0.06
M
0.03
0.03
0.03
0.03
0.03
0.03
0.03
L
0.02
0.02
0.02
0.02
0.02
0.02
0.02
Household Impact for Private Systems
Above Radon Level
(percent of median household income)
WS
25-100
1.12
1.19
1.24
1.27
1.30
1.35
1.51
WS
101-500
0.35
0.42
0.44
0.45
0.45
0.47
0.51
VS
0.16
0.16
0.16
0.16
0.16
0.16
0.16
S
0.07
0.07
0.07
0.07
0.07
0.07
0.07
M
0.04
0.04
0.04
0.04
0.04
0.04
0.04
L
0.02
0.02
0.02
0.02
0.02
0.02
0.02
*4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section 1412(b)(13).
6.7 Summary of Costs and Benefits
Table 6-12 summarizes the central tendency estimates of annual monetized benefits and
annualized costs of the various regulatory alternatives. The central tendency national cost
estimates are greater than the monetized benefits estimates for all radon levels evaluated, although
they are within 10 percent at levels of 1000, 700, 500, and 300 pCi/1. Mitigation costs increase
more rapidly than the monetized benefits as radon levels decrease. However, it is important to
recognize that due to the uncertainty in the costs and benefits estimates, there is a very broad
possible range of potential costs and benefits that overlap across all of the radon levels evaluated.
73
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Table 6-12. Estimated National Annual Costs and Benefits of Reducing Radon
Exposures - Central Tendency Estimate (SMillions, 1997)
Radon Level (pCi/1)
40003
2000
1000
700
500
300
100
Annualized Costs
25
46
98
148
218
373
795
Cost per Fatal Cancer
Avoided
11.3
7.1
5.9
6.0
6.0
6.4
6.9
Annual Monetized
Benefits
13
38
96
145
212
343
673
Notes: 1 . Benefits are calculated for stomach and lung cancer assuming that risk reduction begins immediately.
Estimates assume a $5.8 million value of a statistical life and willingness to pay of $536,000 for non-fatal cancers.
2. Costs are annualized over twenty years using a discount rate of seven percent.
3. 4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section
The total annualized cost per fatal cancer case avoided is $1 1 .3 million at a radon level of
4,000 pCi/1, drops to around $6.0 million for radon levels in the range of 1,000 to 500 pCi/1, and
increase again back to $6.9 million per life saved at the lowest level of 100 pCi/1.
74
-------
Table 6-13. Total Annual Costs and Fatal Cancers Avoided by System Size (SMillions, 1997)*
Radon
Level
(pCi/1)
4000**
2000
1000
700
500
300
100
Total Fatal
Cancers
Avoided
[2.2]
[6.5]
[16]
[25]
[36]
[58]
[115]
Very Very Small
25-100
5.87/0.02/
\\.\[0.06]
22.3 [0.16]
31.4/0.247
42.5 70.357
65.0 [0.56]
123 [1.1]
101-500
11.2 [0.10]
2 1.5/0. 30]
37.5 [0.76]
49.4 [1.1]
63.4 [1.7]
90.7 [2.7]
163 [5.3]
Very Small
501-3300
4.46 [0.34]
8.24 /7.0y
20.3 [2.6]
33.0 [3.9]
49.7 [5.7]
82.78 [9.3]
161 [18.2]
Small
3300-10,000
1 .39 /0 J '57
2.34 [1.1]
5.97 [2.7]
11.0 [4.0]
19.9 [5.9]
44.3 [9.5]
H3fJ8.6J
Medium
10,001-
100,000
1.42 [0.89]
2.65 /2.77
9.15 [6.8]
18.0 [10.2]
33.0 775.07
70.5 724.27
179 747.57
Large
> 100,000
0.18 70.457
0.52 77.47
2.34 [3.4]
4.88 75.27
9.11 /7.57
20.1 772.37
54.8 724.77
* [] =fatal cancers avoided
**4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section 1412(b)(13).
75
-------
Table 6-14. Annual Monetized Health Benefits By System Size (SMillions, 1997)
Radon Level,
pCi/1
4,000**
2,000
1,000
700
500
300
100
Total
Monetized
Health
Benefit*
13 [2.2]
38 [6.5]
96 [16]
144 [25]
212/36/
343 [58]
673 [115]
Monetized Health Benefit by System Size
25-100
0.12
0.37
0.93
1.39
2.05
3.31
6.49
101-500
0.59
1.78
4.48
6.73
9.88
15.96
31.35
501-3,300
2.01
6.05
15.24
22.89
33.59
54.28
106.59
3,301-10,000
2.07
6.17
15.56
23.37
34.30
55.43
108.84
10,001-100,000
5.24
15.80
39.82
59.79
87.77
141.82
278.48
> 100,000
2.66
8.01
20.18
30.30
44.48
71.87
141.12
* [] = fatal cancers avoided
**4000 pCi/1 is equivalent to the AMCL estimated by the NAS based on SDWA requirements of Section 1412(b)(13).
76
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6.8 Sensitivities and Uncertainties
6.8.1 Uncertainties in Risk Reduction and Health Benefits Calculations
The estimates of risk and risk reduction are derived based on models which incorporate a
number of parameters whose values are both uncertain and highly variable. Thus, the estimates of
health risks and risk reduction are uncertain. In addition, to the extent that age-specific smoking
prevalence rates change, the risk from radon in drinking water will change.
The cost of fatal cancers tend to dominate the monetized benefits estimates.
Approximately 94 percent of the cancers associated with radon exposure and prevented by
exposure reduction are fatal cancers of the lung and stomach. In addition, the estimated value of
statistical life ($0.7 to 16.3 million dollars, with a central tendency estimate of $5.8 million,
1997$) is much greater than the estimated willingness-to-pay to avoid non-fatal cancers ($169,000
to $1.05 million, with a central tendency estimate of $536,000,1997$). If the COI measures are
used, non-fatal cancers account for an even smaller proportion of the total monetized costs of
cancers, since the medical care and lost-times costs for lung and stomach cancer are on the order
of $108,000 and $114,000, respectively (1997$).
Unless the VSL is assumed to be near the lower end of its range, the assumptions made
regarding the monetary value of non-fatal cancers are not a major source of uncertainty in the
estimates of total monetary benefits. For most reasonable combinations of values, the VSL is the
major contributor to the overall uncertainty in monetized values of health benefits. As shown in
Table 6-2, the upper and lower estimates of the monetary benefits for a given radon level vary by
a factor of approximately 23, corresponding to the ratios of the lower- and upper-bound estimates
of the VSL.
6.8.2 Uncertainty in Cost and Impact Calculations
The results of the cost and impact analysis are subject to a variety of qualifications. As
discussed in Section 5, the analysis is subject to a variety of uncertainties in the models and
assumptions made in developing cost estimates. One important assumption is that for all CWSs
for which the estimated average radon level exceeds a given level, treatment will be necessary at
all sites. This is a very important assumption, because if systems in reality have only a portion of
sites above the target level, then mitigation costs could be much lower. EPA is currently
evaluating intra-system variability in radon levels, and will address this issue in more detail in the
proposal.
In addition, CWSs are assumed to select from only a relatively small number of treatment
methods, and to do so in known, constant, proportions. In actuality, systems could select
technologies that best fit their needs and optimize operating conditions to reduce costs. The
analysis also relies on various cost-related input data that are both uncertain and variable. Some
of these variables are entered as constants, others as deterministic functions. For example:
treatment technology cost functions are based on EPA cost curves derived for generic systems;
77
-------
households are assumed to use a uniform quantity of 83,000 gallons/year of drinking water,
regardless of geographical location, system size, or other factors; MMM program costs are
assumed to cost $700,000 per fatal cancer case avoided, regardless of the specific types or
efficiencies of activities undertaken by the mitigation programs. One factor the may contribute
significantly to the overall uncertainty in cost estimates is the set of the nonlinear equations
(Appendix C) used to convert population served data to estimates of average and design flow rates
for ground water systems. Relatively small errors in the specification of this model could result in
disproportionately large impacts on the cost estimates. Similarly, the cost curves for some of the
technologies are highly nonlinear function of flow, adding another level of uncertainty to the cost
estimates.
Because of the complexity of the various cost models, EPA has not conducted a detailed
analysis of the uncertainty associated with the various models and parameter values. Limited
uncertainty analyses have been performed, however, to estimate the impact of a few major
assumptions and models on the overall estimates of mitigation costs. First, EPA has analyzed the
impacts of errors of plus or minus 50 percent in the cost curves for the various radon treatment
technologies. The results of this analysis are shown in Figure 6-1. Since water mitigation costs
make up the bulk of the total costs of meeting radon levels in the absence of MMM programs, the
effect of these changes is generally to increase or decrease the costs of achieving the various
levels by slightly less than 50 percent. It can be seen from these results that the assumptions
regarding costs can affect the relationship between costs and monetized benefits. A relatively
small systematic change in water mitigation costs could result in benefit estimates that either
exceed, or are less than, a wide range of radon levels.
In addition to assuming across-the board changes in radon mitigation costs, EPA also
examined the extreme situation in which none of the water systems would adopt GAC treatment.
Since the GAC technologies are the most expensive treatments evaluated, the costs of meeting the
various radon levels are reduced if GAC is eliminated and systems are assumed to employ
aeration instead (Figure 6-1). Since, however, so few systems are assumed to elect GAC in the
first place (five percent or less of the smallest systems) the cost decrease of eliminating GAC is
quite small.
78
-------
Figure 6.1 Sensitivity Analysis of Water
Mitigation Costs
1400
§1200
£1000
^
yz
800
1 _0_ Monetized Benefit
; __Q_ Water Mitigation Cost
j _£_ Water Mitigation Costs + 50%
j _o_Water Mitigation Costs - 50 %
! x Water Mitigation Costs - GAC
m
600
o
O 400
n
'»
C
<
200
0
2,000 1,000 700 500 300
Maximum Radon Exposure Level, pCi/l
100
79
-------
7. IMPLEMENTATION SCENARIOS-MULTIMEDIA MITIGATION PROGRAMS
OPTION
This Section presents a preliminary analysis of the likely costs and benefits under two
different implementation scenarios in which States choose to develop and implement multimedia
mitigation (MMM) programs to comply with the radon NPDWR.
7.1 Multimedia Mitigation Programs
The SDWA, as amended, provides for development of an Alternative Maximum
Contaminant Level (AMCL), which public water systems may comply with if their State has an
EPA approved MMM program to reduce radon in indoor air. The idea behind the AMCL and
MMM option is to reduce radon health risks by addressing the larger source of exposure (air
levels in homes) compared to drinking water. If a State chooses to employ a MMM program to
reduce radon risk, it would implement a State program to reduce indoor air levels and require
public water systems to control water radon levels to the AMCL, which is anticipated to be set at
4000 pCi/1 based on NAS's re-evaluation of the radon water to air transfer factor. If a State does
not choose a MMM program option, a public water system may propose a MMM program for
EPA approval.
The Agency is currently developing guidelines for MMM programs, which will be
published for public comment along with the proposed NPDWR for radon in August 1999. For
the purpose of this analysis, the MMM implementation scenarios are assumed to generate the
same degree of risk reduction as achieved by mitigating water alone. For example, a MMM
scenario which includes the AMCL of 4,000 pCi/1 and a target water level of 100 pCi/1 is assumed
to generate the same degree of risk reduction as the 100 pCi/1 level alone. Thus, the HRRCA
estimates the health risk reduction benefits of MMM implementation options to be the same as the
benefit that would be achieved reducing radon in drinking water supplies alone.
7.2 Implementation Scenarios Evaluated
EPA has evaluated the annual costs and benefits of two MMM implementation assuming
(1) all States (and all water systems) would adopt MMM programs and comply with the AMCL,
and (2) half of the States (and half of the water systems) adopt the MMM/AMCL option. These
scenarios were analyzed in the absence of specific data on States' intentions to develop MMM
programs. The two scenarios, along with the case where the MMM option is not selected by any
States or water systems (presented in Section 6), span the range of participation in MMM
programs that might occur when a radon NPDWR is implemented. At this point, however, it is
not possible to estimate the actual degree of State participation. The economic impacts of the
MMM programs at the system or household level have not been calculated, because there is no
information at present as to how these programs would be funded or upon who the costs would
fall.
80
-------
The presentation of costs and benefits is based on analysis of radon levels of 100, 300,
500,700,1,000,2,000, and 4,000 pCi/1 in public domestic water supplies, supplemented by States
(50 or 100 percent participation) implementing MMM programs and complying with an AMCL
of 4,000 pCi/1.
For the scenario evaluated in which one-half of the States (estimated to include 50 percent
of all CWSs) were assumed to implement a MMM program and comply with an AMCL of 4000
pCi/1 option, while the other half mitigated radon in water to the target radon levels without
MMM programs. In the other scenario, all of the States (and 100 percent of the CWSs) were
assume to adopt MMM programs and comply with the AMCL.
7.3 Multimedia Mitigation Cost and Benefit Assumptions
For the HRRCA, a simplified approach to estimating the costs of mitigating indoor air
radon risks was used. Based on analyses conducted by EPA (US EPA 1992B, 1994C) a point
estimate of the average cost per life saved of the current national voluntary radon mitigation
program was used as the basis for the cost estimate of risk reduction for the MMM option. In the
previous analysis, the Agency estimated that the average cost per fatal lung cancer avoided from
testing all existing homes in the United States and mitigating all those homes at or above EPA's
voluntary action level of 4 pCi/1 is approximately $700,000 (US EPA 1992B). This value was
originally estimated by EPA in 1991. The same nominal value is used in the HRRCA based on to
anecdotal evidence from EPA's Office of Radiation and Indoor Air that there has been an
equivalent offset between a decrease in testing and mitigation costs since 1992 and the expected
increase due to inflation in the years 1992-1997. This dollar amount reflects that real testing and
mitigation costs have decreased, while nominal costs have remained relatively constant. The
estimated cost per fatal cancer case avoided by building new homes radon-resistant is far lower
(Marcinowski 1993). For the purposes of this analysis, only the cost per fatal cancer case avoided
from mitigation of existing homes is used.
To estimate the national cost of the MMM program's air mitigation component, MMM
costs were estimated by multiplying the cost per fatal cancer case avoided by the number of fatal
cases avoided in going from a water radon level equal to the AMCL (4,000 pCi/1) to a water level
equal to various radon levels analyzed in the HRRCA. The number of fatal cancer cases avoided
was estimated using the risk reduction model described in Section 3.
7.4 Annual Costs and Benefits of Multimedia Mitigation Program Implementation
The total annual cost of the radon levels analyzed varies significantly depending on
assumptions regarding the number of States implementing MMM programs. This variation can
be seen Tables 7-1 and 7-2. Under an assumption that 50 percent of States choose to implement
MMM programs, the cost of the rule varies from about $38 million per year to achieve a radon
level in water of 2,000 pCi/1 to about $450 million per year to achieve an level of 100 pCi/1.
Assuming that 100 percent of States implement MMM programs, the cost of the rule varies from
81
-------
about $29 million per year to achieve an radon level of 2,000 pCi/1 to about $106 million per year
to achieve an level of 100 pCi/1.
The monetized benefits of both MMM implementation scenarios exceed the estimated
mitigation costs across all radon levels. When the 50 percent MMM participation scenario is
evaluated, the mitigation costs at 2,000 pCi/1 are just less than the estimated benefits ($38 million
versus $39.6 million, respectively). In the case of 100 percent multimedia participation,
mitigation costs begin at about 65 percent of the benefits at a radon level of 2,000 pCi/1, and
decrease rapidly so that at 100 pCi/1 the monetized benefits of radon reduction exceed the
mitigation costs by almost 7-fold.
Assuming 50 percent MMM participation, the total cost per fatal cancer case avoided is
$5.8 million at a radon level of 2,000 pCi/1, dropping to around $3.7 million at a level of 500
pCi/1, and increasing slightly to about $3.9 at 100, pCi/1 (Table 7-1). As expected, the cost per
fatal cancer case avoided is lowest for the 100 percent MMM participation option, ranging from
from $4.5 at a radon level of 2,000 pCi/1 to about $900,000 at a level of 100 pCi/1.
For the 50 percent MMM participation, the incremental cost per fatal cancer case avoided
decreases from 2000 pCi/1 to 500 pCi/1 ($8.7 million to $3.4 million, respectively), then increases
to $4.1 million at 100 pCi/1. In the case of the 100 percent MMM participation, the incremental
cost per life saved starts at about $4.3 million for the maximum target levels of 2,000 pCi/1, and
then drops sharply to about 700,000 per life saved for the other radon.
82
-------
Table 7-1. Central Tendency Estimates of Annualized Costs and Benefits of Reducing
Radon Exposures with 50% of States Selecting the MMM/AMCL Option (SMillion, 1997)
Radon
Level
(pCi/1)
Baseline
4000
2000
1000
700
500
300
100
Water Mitigation Component
Annual
Costs*
0
25
35
61
86
121
199
410
Annual
Benefits
0
13
25
54
78
112
177
341
Fatal
Cancer
Cases
Avoided
0
2.2
4.3
9.0
13
19
30
58
Cost Per
Fatal
Cancer
Case
Avoided
—
11.3
8.2
6.6
6.4
6.3
6.6
7.0
Multimedia Mitigation Component
Annual
Costs
0
0
2.3
5.8
8.6
12.7
20
40
Annual
Benefits
0
0
13
42
66
99
164
328
Fatal
Cancer
Cases
Avoided
0
0
2.2
7.1
11
17
28
56
Cost Per
Fatal
Cancer
Case
Avoided
0
0
1.1
0.81
0.77
0.74
0.73
0.71
*Equivalent to the cost of complying with an AMCL of 4000 pCi/1
83
-------
Table 7-2. Central Tendency Estimates of Annualized Costs and Benefits of Reducing
Radon Exposures with 100% of States Selecting the MMM/AMCL Option (SMillion, 1997)
Radon
Level
(pCi/1)
Baseline
4000
2000
1000
700
500
300
100
Water Mitigation Component
Annual
Costs*
0
25
25
25
25
25
25
25
Annual
Benefits
0
13
13
13
13
13
13
13
Fatal
Cancer
Cases
Avoided
0.0
2.2
2.2
2.2
2.2
2.2
2.2
2.2
Cost Per
Fatal
Cancer
Case
Avoided
—
11.3
11.3
11.3
11.3
11.3
11.3
11.3
Multimedia Mitigation Component
Annual
Costs
0.0
0.0
4.6
12
17
25
41
80
Annual
Benefits
0.0
0.0
25
83
131
198
328
654
Fatal
Cancer
Cases
Avoided
0.0
0.0
4.4
14
23
34
56
112
Cost Per
Fatal
Cancer
Case
Avoided
0.0
0.0
1.1
0.81
0.77
0.74
0.73
0.71
* Equivalent to the cost of complying with an AMCL of 4000 pCi/1
7.6 Sensitivities and Uncertainties
EPA conducted a sensitivity analysis associated with potential uncertainty in the cost-
effectiveness of MMM programs. Since the value used is a point estimate ($700,000 per life
saved), and since the ability to employ MMM programs results in substantial decreases in
estimated costs, it might be expected that changes in the cost-effectiveness value would affect the
cost estimates for these options substantially. Figure 7-1 summarizes the impact of different
estimates of the cost of MMM programs on the total cost of radon mitigation. Costs are graphed
for the 50 percent and 100 percent participation options for radon level. Costs were estimated for a
high-end case (assuming a MMM cost 50 percent above the central tendency value), a low-end
case (50 percent below the central tendency), and for a central tendency case that assumes the
current $700,000 per life saved as the MMM cost.
The relative impacts of changing MMM costs on the total costs of reducing radon exposure
can also be seen in Figure 7-1. The figure illustrates that the central tendency estimate of
monetized benefits is e well above the estimated costs for all ranges except for the high-end
estimate of the 50 percent MMM participation scenario. This is due to the greater impact of water
mitigation costs relative to the MMM cost component to total costs compared to the 100 MMM
scenario, where the MMM component contributes the largest share to total costs.
84
-------
Figure 7-1. Sensitivity Analysis to Changes in
Multimedia Cost Estimates
a
0)
c
o
0)
o
O
c
o
ys
a
O)
700
600
500
400
300
200
100
0
_j... .4.... 50 Percent Part., High-End
. 50 Percent participation
. 50 Percent part., Low End
100 Percent part., Low End
. 100 Percent Participation
-100 Percent Part., High End
. Monetized Benefit
2,000 1,000 700 500 300
Maximum Radon Exposure Level, pCi/l
100
85
-------
References
Davis, RMS and JE Watson Jr. "The Influence of Radium Concentration in Surrounding Rock on
Radon Concentration in Ground Water," University of North Carolina, Chapel Hill: March
13,1989.
Longtin, J.P. "Occurrence of Radon, Radium, and Uranium in Groundwater." Journal of the
American Water Works Association. July, 1987.
Marcinowski, F. and S. Napolitano. "Reducing the Risks from Radon." Air and Waste, Vol. 43,
955-962,1993.
NAS. 1998A. "Health Effects of Exposure to Radon - BEIR VI (Pre-Publication Copy)," National
Academy Press: Washington, DC.
NAS. 1998B. "Risk Assessment of Radon in Drinking Water (Pre-Publication Copy)," National
Academy Press: Washington, DC, September 15.
US EPA. 1999A. "Point Estimate of Radon Unit Risks," Memo to Mike Osinski from Nancy Chiu,
Office of Science and Technology, January 22.
US EPA. 1999B. "Radon in Drinking Water Health Risk Reduction and Cost Analysis:
Appendices," Office of Ground Water and Drinking Water, February.
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of-Entry Treatment Units," Office of Ground Water and Drinking Water.
US EPA. 1998B. "Cost of Lung Cancer (Draft)," Office of Ground Water and Drinking Water,
October.
US EPA. 1998C. "Cost of Stomach Cancer (Draft)," Office of Ground Water and Drinking Water,
October.
US EPA. 1998D. "Evaluation of Full-Scale Treatment Technologies at Small Drinking Water
Systems: Summary of Available Cost and Performance Data," Office of Ground Water and
Drinking Water, December.
US EPA. 1998E. "Guidelines for Preparing Economic Analyses - Review Draft," Office of Policy,
November.
US EPA. 1998F. "Health Risks from Low-Level Environmental Exposure to Radionuclides,"
Office of Radiation and Indoor Air, Federal Guidance Report No. 13, Part I - Interim
Version, EPA 401/R-97-014.
86
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US EPA. 1998G. "Model Systems Report (Draft)," Office of Ground Water and Drinking Water,
March.
US EPA. 1998H. "National-Level Affordability Criteria Under the 1996 Amendments to the Safe
Drinking Water Act," Office of Ground Water and Drinking Water, August 19.
US EPA. 19981. "National Primary Drinking Water Regulations: Disinfectants and Disinfection
Byproducts; Final Rule," 63 FRNo. 241, 69390-69476, December 16.
US EPA. 1998J. "Potential Benefits of the Ground Water Rule - Draft Final Report," Office of
Ground Water and Drinking Water, February.
US EPA. 1998K. "Radon Cost Estimate," Memo to Bill Labiosa from H. McCarty, Office of
Ground Water and Drinking Water, December 4.
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States - External Review Draft," Office of Ground Water and Drinking Water, September
30.
US EPA. 1998M. "Regulatory Impact Analysis of the Stage I Disinfectants/Disinfection By-
Products Rule," Office of Ground Water and Drinking Water, November 12.
US EPA. 1998N. Safe Drinking Water Suite Model. Inputs from Version 3.4 of the Cost Library
and Version 4.0 of the What If Module.
US EPA. 1998O. "Technologies and Costs for the Removal of Radon From Drinking Water,"
Office of Ground Water and Drinking Water, September.
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and Methodology Report." Office of Ground Water and Drinking Water. EPA 815-R-97-
00Ib,January.
US EPA. 1997B. "Withdrawal of the Proposed NPDWR for Radon-222," 62 FRNo. 151,42221-
42222, August 6.
US EPA. 1995. "Uncertainty Analysis of Risks Associated with Radon Exposures in Drinking Water,"
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and Your Family from Radon," Office of Radiation and Indoor Air. EPA-402-K92-001,
September.
US EPA. 1994B. "Final Draft for the Drinking Water Criteria Document on Radon," Office of Water,
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87
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US EPA. 1994C. "Report to the United States Congress on Radon in Drinking Water, Multimedia
Risk and Cost Assessment of Radon," Office of Water. EPA-811 -R-94-001.
US EPA. 1993 A. "EPA's Map of Radon Zones: National Summary," Office of Air and Radiation,
EPA 402-R-93-071, September.
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Water," Office of Science and Technology, April 30.
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Radiation, EPA 402-R-92-011, October.
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MINEDOSE Code," Memo to Greg Helms from Marc Parotta, Office of Ground Water and
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88
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APPENDIX A. EQUATIONS AND PARAMETER VALUES
USED IN THE ASSESSMENT OF RISKS AND RISK
REDUCTION BENEFITS
-------
Exhibit A-1. Risk Equation and Variable Definitions Used in Radon Risk
Assessement
1. Risk Equations for Inhalation of Radon Progeny
IR(prog) = Cw*TF * EF * OF * 0.516 • iRF(prog)
PR(prog) = IR(prog) * Pop
2. Risk Equations for Ingestion of Radon Gas in Drinking Water
|R(ingest) = Cw * V F * 365 * oRF
pR(ingest) = IR(ingest) * Pop
3. Risk Equations for Inhalation of Radon Gas
IR(gas) = Cw * TF * BR * 24* OF * 365 * iRF(gas)
PR(gas) = IR(gas) * Pop
4. Equation for Total Population Risk
PR(total) = Pr(prog) + PR(ingest) + PR(gas)
Variable Definitions
IR(prog) Individual risk associated with inhalation of radon progeny, lifetime fatal cancer risk per
year of exposure
PR(prog) Population risk from inhalation of radon progeny, fatal cancers per year of exposure
IR(ingest) Individual risk associated with ingestion of radon gas, lifetime fatal cancer risk per year of
exposure
PR(ingest) Population risk from ingestion of radon gas, fatal cancers per year of exposure
IR(gas) Individual risk associated with inhalation of radon gas, lifetime fatal cancer risk per year of
exposure
PR(gas) Population risk from inhalation of radon gas, fatal cancers per. year of exposure
PR(total) Total population risk, fatal cancers per year of exposure
Cw Radon activity level in water, pCi/l
TF Transfer factor for domestic water use, pCi/l(air)/pCi/l(water)
EF Equilibrium factor (unitless)
OF Occupancy factor (unitless)
iRf (prog) Risk Factor for inhalation of progeny, fatal cancer risk per wlm (working level month)
Pop Population exposed
V Volume of direct water ingestion, liters/day
F Fraction of radon remaining in drinking water, unitless
°Rf Risk Factor for radon ingestion, fatal cancer risk per pCi
BR Breathing rate, liters per hour
iRf(gas) Risk Factor for inhalation of radon gas, fatal cancer risk per pCi
Simulation Parameters
Type of sampling One-domensional Latin Hypercube
Number of iterations 5 X 50,000
Seed sumbers First run = 1027; subsequent runs, chosen randomly by program
A-1
-------
Exhibit A-2. Variable Values Used in Radon Risk Assessment
Variable
Cw (baseline)
Cw(with maximum
exposure limits)
Pop
TF
EF
OF
V
F
BR
iRF(prog)
oRF(ingest)
iRF(gas)
Distribution Type
LN(gm, gsd)
Variable
Point estimates
Point estimate
Point estimate
Point estimate
Point estimate
Point estimate
Point estimate
Point estimate
Point estimate
Point estimate
Value
System Size gm, pCi/l gsd, pCi/l
25-100 312 3.04
101-500 259 3.31
501-3,3300 122 3.22
3,301-10,000 124 2.29
>1 0,000 132 2.31
If Cw(baseline) < limit, Cw(baseline)
If Cw(baseline) < 2*limit, Cw(baseline)/2
If Cw(baseline) < 5*limit, Cw(baseIine)/5
If Cw(baseline) > 5*limit, Cw(baseline)/100
System Size Population
25-100 865,245
101-500 4,176,468
501-3,3300 14,239,295
3,301-10,000 14,542,812
>1 0,000 55,907,052
1.0X10"4 pCi/l(water)/pCi(air)
0.4 unitless
0.7 unitless
0.6 liters/day
1 unitless
22,000 liters/hour
5.1 5X1 0 fatal cancer risk per wlm
4.25X1 0 fatal cancer risk per pCi
1 .52X1 0 fatal cancer risk per pCi
1. LN = lognormal distribution, gm = geometric mean, gsd = geometric standard deviation
-------
APPENDIX B. COST CURVES FOR RADON REDUCTION AND
DISINFECTION TECHNOLOGIES
-------
PTA Capital Costs
80 % Removal, 5 min. Detention
W
o
o
3
a
ro
O
y=159004x
,0.435
0.01
0.1
10000000
-1000000-
-10000-
.IQQQ
y=114783x
°-8977
y = 174908x
,0.6827
1 10
Design Flow, MGD
100
O small systems
A large systems
X Transition Zone
•—•Power (small systems)
— Power (Transition Zone)
Power (large systems)
12/18/98
Unitsum2.xls
-------
PTA O&M Costs, 80% Removal
1000000
y=9597.3x + 3414.2
W
O
O
3
C
= -20889x2+17044x
1411.3
0.001
0.01 0.1 1 10
Average Daily Flow, MOD
100
O < 0.33 MGD Avg. Daily
O 0.33 - 4.33 MGD Avg. Daily
A > 4.33 MGD Avg. Daily
X Breakpoint check
Poly. (< 0.33 MGD Avg. Daily)
—Poly. (0.33-4.33 MGD Avg. Daily)
Linear (> 4.33 MGD Avg. Daily)
12/18/98
Unitsum2.xls
-------
PTA O&M Costs, 99% Removal
1000000
y =
I4929X + 6844.3
-100000-
CO
o
o
otf
o
"ro
c
= 602.29x2 + 13770x + 2431
1000-
= -28422x2 + 24415x
HQQ
1540.4
0.001
0.01 0.1 1 10
Average Daily Flow, MGD
100
O < 0.33 MGD, Avg. daily
O 0.33 - 4.33 MGD, Avg. daily"
A > 4.33 MGD,, Avg. daily
Poly. (< 0.33 MGD, Avg. daily)
—Poly. (0.33 - 4.33 MGD, Avg. daily")
Linear (> 4.33 MGD,, Avg. daily)
12/18/98
Unitsum2.xls
-------
JS
w
o
o
3
'a
re
O
Diffused Aeration: Capital Costs, Treatment Only
100000000
y = 8.6692X3 + 1443.7x2 + 193324X + 1E-»-06
-10000-
= 75723X3 - 75379X2 + 316041x + 7124
-4060-
y = 299755x + 23754
0.01
0.1
10
100
Design Flow, MGD
O 0.015 < Flow < 1.0
D 1.0 < Flow < 10
O 10 < Flow < 100
—Poly. (0.015 < Flow < 1.0)
—Linear (1.0 < Flow < 10)
Poly. (10 < Flow < 100)
12/18/98
Unitsum2.xls
-------
DA O&M Costs, 80% Removal
10000000
-1000000
y = 262.21xJ - 3244.9x" + 74263x -
W
o
o
to
3
C
0.001
-100000
y = -30228x2 + 76786x + 895.57
y = 52380x + 63647
0.01 0.1 1 10
Average Daily Flow, MGD
100
O < 0.33 MGD, Avg. daily flow
O 0.33 - 4.33 MGD, Avg. daily flow
A > 4.33 MGD, Avg. daily flow
Poly. (< 0.33 MGD, Avg. daily flow)
Poly. (0.33 - 4.33 MGD, Avg. daily flow)
——Linear (> 4.33 MGD, Avg. daily flow)
12/18/98
Unitsum2.xls
-------
GAC Capital Costs, 50% removal
10,000,000
y = -499779X2 + 2E+06x + 348780
0,000
o
o
a.
to
O
y = 2E+08X3 - 5E+07X2 + 7E+06x + 159271
-1-OOiOOO-
10,000
O < 0.10 MGD design flow
A 0.1-1.0 MGD
— Poly. (< 0.10 MGD design flow)
— Poly. (0.1-1.0 MGD)
0.01
0.10
Design Flow, MGD
1.00
-------
GAC O&M Costs, 50% removal
42
(/>
o
o
o*
O
c
100,000
y = -134464X2 + 99041x + 15687
y = 4E+08x - 2E+07x + 573696x + 11912
, , 10,000
O < 0.10 MOD design flow
A 0.1-1.0 MOD
— Poly. (< 0.10 MOD design flow)
—Poly. (0.1-1.0 MOD)
0.0010
0.0100 0.1000
Average Daily Flow, MQD
1.0000
12/18/98
Unitsum2.xls
-------
GAC Capital Costs, 80% removal
V)
o
o
3
'5.
to
O
10.000.000
y = -875639X2 + 3E+06x + 407890
17000T000-
y = 3E+08x3 - 8E+07x2 + 1E+07x + 189645
1.0E-02
1.0E-01
Design Flow, MGD
-1-OOiOOO-
10,000
1 .OE+00
O < 0.10 MGD design flow
A 0.1 -1.0 MGD
— Poly. (< 0.10 MGD design flow)
— Poly. (0.1-1.0 MGD)
-------
GAC O&M Costs, 80% removal
100000
O
O
ofl
O
"w
3
C
C
y = -170031X2 + 141675X + 15772
y = 4E+08X3 - 2E+07x2 + 626674x + 11937
10000
O <0.10MGD design flow
A 0.1 -1.0 MOD
—Poly. (< 0.10 MOD design flow)
— Poly. (0.1-1.0 MOD)
0.0010
0.0100 0.1000
Average Daily Flow, kgpd
1.0000
12/18/98
Unitsum2.xls
-------
GAC Capital Costs, 99% removal
CO
o
o
.1
'a.
(0
O
10,000.000
y = -926925X2 + 7E+06x + 566755
y = -4E+07xJ - 3E+07x^ + 1E+07x + 273237
-100T000
10,000
1.0E-02
1.0E-01
Design Flow, MGD
1.0E+00
O < 0.10 MGD design flow
A 0.1 -1.0 MGD
— Poly. (< 0.10 MGD design flow)
— Poly. (0.1 -1.0 MGD)
-------
GAC O&M Costs, 99% removal
10000000
y = -5E+06x2 + 8E+06X + 231756
o
o
06
o
3
C
c
1000000
y = 2E+09x3 - 3E+08x2 + 2E+07x + 94302
_ 100000
10000
O < 0.10 MGD design flow
A 0.1-1.0 MGD
— Poly. (< 0.10 MGD design flow)
— Poly. (0.1 -1.0 MGD)
0.0010
0.0100 0.1000
Average Daily Flow, kgpd
1.0000
12/18/98
Unitsum2.xls
-------
Chlorination Capital Costs
1000000
y
tn
o
O
a.
to
O
= 0.4592x + 37155
y=171133x-9051.6
-10000-
\
y = 8062
= -0.157x3 + 7.3062X2 + 5648.2x + 40652
y = 6728x + 30427
O <0.10MGD
D 0.10-0.27 MOD
O 0.27 -1.0 MGD
+ 1.0-10 MGD
X > 10 MGD
—Linear (<0.10 MGD)
—Linear (0.10 - 0.27 MGD)
Linear (0.27 -1.0 MGD)
Linear (1.0-10 MGD)
—Poly. (> 10 MGD)
0.01
0.1
10
100
Design Flow, MGD
12/18/98
Unitsum2.xls
-------
Chlorination Treatment Only, O&M Costs
1000000
y = 0.0035x3 + 0.9774x
1 + 1541.7x + 10132
-100000
W
O
o
oft
O
15
3
C
C
= 1176.9*
3862.2
10000-
y = -51464X2 + 18713X + 2678.1
= 339.61x + 15325
= 355205x + 2822 1x + 2160
-1000-
O < 0.026 MOD, Avg. Daily Flow
O 0.026 - 0.078 MGD, Avg. Daily Flow
A 0.078 - 0.33 MGD, Avg. Daily Flow
X 0.33 - 4.33 MGD, Avg. Daily Flow
X > 4.33 MGD, Avg. Daily Flow
Poly. (< 0.026 MGD, Avg. Daily Flow)
• - - Poly. (0.026 - 0.078 MGD, Avg. Daily Flow)
Poly. (0.078 - 0.33 MGD, Avg. Daily Flow)
Linear (0.33 - 4.33 MGD, Avg. Daily Flow)
Poly. (> 4.33 MGD, Avg. Daily Flow)
0.001
0.01 0.1 1 10
Average Daily Flow, MGD
100
12/18/98
Unitsum2.xls
-------
2-Days of Storage, Capital Costs
Steel Tank Above Ground, Plus Effluent Pumping, Includes Disinfection Capital
y = 410569x
0.7373
-100000-
y = 218353X
0.4583
40GGQ-
-4000-
O < 0.1 MGD
O >0.1 MGD
—Power (< 0.1 MGD)
Power (>0.1 MGD)
0.01
0.1
Design Flow, MGD
-------
APPENDIX C. FLOW ESTIMATION EQUATIONS FOR PUBLIC
AND PRIVATE WATER SYSTEMS
-------
EXHIBIT C-1. EQUATIONS FOR ESTIMATING FLOW
Flow (MGD) = a * (pop/1000)Ab
Average Flow CAP) m:^ K-k^^*fi«ili^^
Public Water Systems
a= 0.1284
b = 1,0584
Private Water Systems
a= 0.1029
b = 1 .0628
Design- Flow (DF)./-^\;:-"F;:?->^-^?^; . - - --'
Public Water Systems
a = 0.4041
b = 0.9554
Private Water Systems
a= 0.3179
b = 0.9608
Public Water Systems *
System Size
25-100
101-500
501-1,000
1 ,000-3,300
3,301-10,000
10,001-50,000
50,001-100,000
>1 00,000
Average
Population
65
290
750
1880
5800
20900
68000
214000
AF, mgd
0.0071
0.0346
0.0947
0.2505
0.8252
3.2049
11.1710
37.5902
DF, mgd
0.0297
0.1238
0.3070
0.7386
2.1670
7.3749
22.7650
75.1805
Private Water Systems r :
System Size
25-100
101-500
501-1,000
1 ,000-3,300
3,301-10,000
10,001-50,000
50,001-100,000
>1 00,000
Average
Population
60
230
720
1800
5700
21900
68000
248000
AF, mgd
0.0052
0.0216
0.0726
0.1922
0.6543
2.7355
9.1202
36.0777
DF, mgd
0.0213
0.0775
0.2319
0.5592
1 .6925
6.1686
18.3217
72.1554
1. Flow parameters estimated by ODWGW from SDWIS data
C-1
-------
APPENDIX D. SUMMARY COST TABLES
-------
Ruults (1OO MCI.)
PUBLIC
Monitoring Costs,
Colt Fnqumcy
MonllorinaCost * so *
SyllimaiM No. otSlt.i No. ofSyit«m»
11-100 11906 tM)
I01-600 4746.0 3924
604-1000 3550.4 2518
1001-3,100 6361.1 3741
1,101-10.000 43368 1902
10,001-60.000 3886.3 997
10,001-100.000 683.1 113
100.01)1.1.000.004 457.6 52
Toul Annuil
Monitoring Can
231,112
<4i.eoo
710,076
1,272.020
867.312
777.660
164.620
•1.920
Coil pir Syitim
224
242
212
340
458
760
1,740
1.760
SyMlm Sin No. 01 Slut No. ol Sylliml
W» 59366 4BI7
VS 99135 6201
S 43386 1002
M 48714 1110
L 457.6 a
Toll! Annuil
Monitoring Coil
1.167,720
l.«62,696
887.312
•74,260
•1.620
Coil pir Sylltm
330
117
456
676
1,760
Total!
Syilim ain
21-100
101-600
101-1000
1001-1.100
1,901-10.000
10.001-60.006
60.001-100.000
100,001-1.000.000
Toul
01M Coil t
5,702,175
26.464.767
11.413.6SS
32,012.119
14.716.416
38,066.122
13.146.435
16.475.711
176.031.419
nnuil Cap Coal
5.262,336
26,326.443
20.679.264
51,225.397
60.029.676
75.976.617
22.642.750
27.552.676
291.697,163
Cip Colt t
55.749,268
100.090.740
219.076,421
S42,662,5>1
635,955.259
604,916,556
241.996.415
291.693.441
3.092.362.705
Innuil Monitoring Coil
216.112
949,606
710.076
1.272,620
607.312
777.660
196,620
91.520
Total Annual
Coil
11.202.629
55.740.636
12.602.996
64.510.115
•5.613.406
114.854,399
16.187.605
44,119,907
5.103.528 !* > 475.0M.110
Par Syslsm Costs
Syllim Sll» OtM Colt A
26-100 t 5.702.17S
101-600 J 26.464,767
501-1000 11.411,655
1001-1,100 32,012,119
1,101-10.000 14,716,416
10,001-60,000 16,095.122
10,001-100,000 11,148.415
100,001-1,000,000 10,475,711
nnual Cap Coil No. ol situ Abovi
Rig. Limit
5.262.336 1.004
28.326.443 3.715
20.679,264 2.341
51.225.397 4,195
60.029.676 3.197
75.976,617 2.865
22.642,750 724
27.552.876 337
Monitoring Coil lor
Byltimi Abovi Rig.
Llmll
200.781
742.936
466.104
639,059
639.391
573.097
144,699
67.446
SyillmSIn OtM Coil Annual Cap Coil Cap Coil Annuil
Monitoring
Coil
W8 32,166.062 33.566.T61 355.640.02) 1.187.720
VS 43.425.774 71.904,661 761.759.004 1.862.696
6 34,716,416 60.029.676 635.955.251 667.112
M 51.246.557 96,621.367 1.046.914.971 974.260
L 16.475.711 27.552,676 291,693,441 91,520
Total 175.011.419 291.697.163 1092.162.705 5,103.528
No. of Syl. Coil pir
Abovi Rig. Syitim
Limit
896 I 12.456
3.070 » 16,080
1.660 19.613
2.468 34.069
1.402 66.027
735 150,041
83 433.934
38 1.150.683
SyilimSIzi OtM Coil Annuil Cip Coil No. ollllii
Abovi Rig.
Llmll
WS ( 12,166.962 33,586,761 4.719
VS t 43.425.774 71,904.661 6.516
S t 34.716.416 60.029.676 3.197
M I 51.246.557 86,621.167 1,590
L t ie.47S.71l 27.552.676 117
Total
66.941,461
117.111.111
•9.611.406
151.042.204
44,119,907
$^-**47S,032£110J
Monitoring Coil No. OfSyl. CoMpM
lor Syltiml Abovi Rig. Syitim
Afcov. Rig. Limit Umll
i 041.719 19661 1 16816
1 1.107.221 4,1260 I 26.255
t 610.191 1,4022 1 06.027
t 717.917 616.0 t I64.1J1
* 67.446 16.1 1 1.150.663
Household Coils HH Conuimpllon (gal): ".000
SyllimSlz* QlMCoil Annuil Cip Coil Monitoring Coil lor Avmgi Dilly Flow No. olSyi. HH
Syitimi Abovi Rig |MGD| Abovi Rig.
ncramintal
Limit Limit Coil
15-100
101-600
801-1000
1001-1,100
1,101-10,000
10,001-60,000
60.001-100,000
100,001-1,000,000
5,702.175
26.464,767
11.411,655
12.0I2.IW
34,716,416
36.096.122
11,148.439
5,262.335
28.326.443
20.079.264
51,225,397
60,029.676
75.976.617
22.642.750
16,475.711 1 27.5S2.676
200.711 00071 696
742,931 00346 3.070
461.164 00947 1,660
639.099 02505 2,466
639,391 0.6252 1,402
573,097 32048 735
144,699 11.1710 83
67.446 379902 38
398.13
11875
47.10
3093
18.75
11 07
683
696
Sytttm Sill
WS
VS
S
M
L
OlM Coil
12.166,062
43,425,774
34,716,416
51,246.557
16.475.711
Annual Cip Coil Monitoring AvitigiDilly Afficlid
Coil lor Flow (MOD) 6yitimi
Syiumi
Abovi Rig,
Limll
11,986.761 t 843.719 0,0264 3,9661
71.904,661 * 1.307.221 0.1676 4.126.0
60.029.676 t 610.191 06252 1.402.2
96.621,367 i 717,997 4015) 611.0
27,952.676 t 67,446 17.5902 361
HH
InuMMnUI
Ceil
11456
94.21
1675
1044
6.96
01-1
-------
Results (100 MCL)
PRIVATE
Monitoring Cost*
. 'li Coil Fraquancy
Monitoring Co«t I u 4
Syalam Siia No. of Sllai No. ol Syitami
11-100 133188 11(90
101-400 11257.) 9304
501-1000 22560 1900
1001-3,100 23052 1356
3.301-10.000 9439 414
10,001-10.000 (48.1 217
90.001-100,000 200.1 23
100,001-1,000,000 114. « 13
Tolll Annual
Monitoring Coll
2,663.300
2.251.561
451.200
461.040
1M.7<4
169,260
40.020
22.680
Cost par Syitem
224
242
212
340
456
780
1.740
1.760
lyitimSlia No. of Silo No. of Syilimi
WS 24574.0 211940
Va 4561.2 29560
S B43.0 414.0
M 1046 4 240 0
L 1144 130
ToliI Annual Colt par tyltim
Monitoring Coil
4.914.92) t 232
812.240 t 309
111.704 » 45«
201.280 1 872
22.080 t 1.760
Totol*
Syilam Blza
11.100
101-600
S01-1000
1001-1,300
1,101-10,000
10,001-60,000
50,001-100,000
100,001-1,000,000
Total
O6.M Coil /
58,338,824
51.576.0SO
6.196,099
9.761,699
6.431,975
7,291,530
2.291.240
3,960.450
145.676.779
Annual Cap Coat
it.067.497
53.556.642
11.190,843
15.123.646
11.177,574
14.655.706
4.027,9*6
6.662,795
168,164,656
Annual Cap Coat 1
541.009.794
567.401.01)
118,555,955
167,635,954
116,415.170
155.262.77)
42.672.135
70.585.750
1.761.538,761
rout Annual Monitoring
Coil
2.663.360
2,251.568
451,200
461.040
186.7)4
169.260
40,020
22.880
6,246.112
Tolll Annual
Coil
112.069.661
107.389.169
17.640.141
26,066,3)7
17,600.313
22.116,504
6.359,207
10,646.125
320.289,647
Syilam Slia DIM Colt Annual Cap Coil Cap Coll
WS ! 109.917,782 t 104,626,139 1 1,108.410.812
VS 1 15.981.797 I 27.014.492 i 2)6.1)1.909
8 t 6,433.975 1 11.177,574 1 118.416.378
M t 9.582.775 I 16.663.656 I 197.934,011
L > 3.960.450 S 6,682.795 t 70.5)5,750
Total 1 145.876.779 t 166,164.656 t 1,711,518.761
Annual
Monitoring
Con
4,014.92)
912.240
1B1.784
209,2)0
22.6)0
6.246,112
Total ,
I 219,45),649
t 41.001,52)
$ 17,600.111
$ 28.475.711
1 10,646.125
'|M£=S50,2Wi64jT
P«r Sy«t«m Co»t»
Syllam Sill
M-100
101-600
601-1060
1001-1,300
1,101-10.00)
10,001-60,000
10,001-100.000
100,001-1,000,000
DIM Coil
58.338.824
S1.576.9S6
6.198.096
9.763.699
6.413,975
7.291.536
2.291,240
3,960,450
tanual Cap Cosl No. of Sitai Abova
Rag. Limit
51.067.497 11.229
53,550.642 6.108
11.190.843 1.467
15.823.648 1.520
11.177,574 696
14,655.708 624
4.027.946 147
6.662.705 64
Monitoring Cost lor No. of Syl.
Syiltma Abowa Rag. Abova Rig.
Limit Limit
2.245.604 10.026 1
1,761,542 7,279
297.483 I.OSS
301.971 694
139,173 305
124.7M 160
29.493 17
16.661 10
Coat par
Syitam
11.136
14.686
16.766
26.983
58.160
136.020
374.556
1,110,616
Syilim Sin
WS
vs
S
M
L
DIM Coil
109.017.782
15.901.797
6.431.975
9.582.775
3.960,450
Annual Cap Coit No. ol Situ
Abova Rag.
Llmil 1
104.026.130 20.037
27.014,492 3,007
11,177.574 690
16,601.650 771
6.662.79S 84
Monitoring Coal No. ot Syl.
lor Byitirna Abova Rag.
kbova Rag. Llmll Umll
4.007.346 17.305,0
601.454 1.040.0
139,171 305.2
154,229 1769
16,661 96
Coil par
lyilant
12.829
22.370
50,160
160,6)0
1.110.010
Hounhold CoiU HH Consumption (gal):
83.000
Syilem Siza
11-1)0
101-600
101-1000
1001-1.100
1,101-10,000
10.001-40,000
90,001-100,000
100,001-1.000,000
DIM Colt 1
58,338.824
51,576.950
0.19).09)
9,713,699
0.433.975
7.291.636
2.291.240
3.960.450
Annual Cap Coil
9
St.067.4B7
53,558,042
11.190,843
15.823,648
11,177.574
14.055,70)
4,027.946
6.662,795
Monitoring Coil for Avaraga Daily flow No. of Syl.
yalama Abova Nag (MOD) Abova Rig.
Llmil Llmil
2.245.004 00052 10.020
1,761.542 00216 7,279
297,463 0.0726 1,055
303,971 0 1922 094
139.173 06543 305
124.736 2.7355 160
29,491 9.1202 17
10,861 360777 10
HH
Incramanlal
Coil
4)9.43
154.75
5253
3429
2021
1147
934
700
Syitim Slia
WS
VS
S
M
L
OlMCoil Annual Cap Coal
109.017.702 1 104,620.139
15,011,797 S 27,014,491
6.433.975 * 11,177.574
9.512.775 | 10.6)1.658
3,960.450 t 6.662.7B5
Monitoring Avaraga Dally AfllcWd
Coil for Flow (MOD) Syllama
Syiliml
Abova Rag.
Limit
4.007.346 00121 17.3050
601.454 0.1274 1.948.9
139.171 06543 305,2
134.229 33474 1769
16.661 360777 96
HH
IncnmanUI
COM
3M.U
19.91
20.11
10.02
700
OI-2
-------
Results (200 MCL)
PUBLIC
Monitoring Costs
Cost
Monitoring Cost * so
Frequency
4
System Sift No. of Sites No. ol
Systems
21-100 1190.6 1063
101-SOO 47480 3924
S01-1000 3550.4 2516
1001-3,300 6363.1 3743
3,301-10,000 4336.S 1902
10,001-50,000 3888.3 997
SO.001-100,000 083.1 113
100,001-1,000,000 4576 52
Toll) Annual
Monitoring Cost
238,112
849.606
710.076
1.272,620
867.312
777,660
1 196,620
I 91,520
Cost psr System
224
242
282
340
456
780
1,740
1,760
System Slra No. of Site* No. of
Systems
WS 5938.6 4987
VS 9913.S 6261
S 43366 1902
M 4871.4 1110
L 457.6 52
Totsl Annusl
Monitoring
Cost
1,187,720
1,982.696
667.312
974,260
91.520
Cost per System
238
317
456
678
1,760
ToUlt
System Size DIM Coil Annual Cap
Cost
25-100 3.750.191 3.753.595
101-SOO 17,918.198 20.573,008
501-1000 6,188.040 13.911.373
1001-3,300 22.973.634 34,824.876
3,301-10,000 23.876,791 39,999,667
10,001-50,000 24,199,442 46,144.477
50,001-100,000 7.757.091 13.473.336
100,001-1,000,000 9,619.194 16,026,923
Tote) 1116.282.581 S 168.707.255
Per System Costa
System Sin OiM Cost Annual Csp
Cost
25-100 3.750,191 3.753.59S
101-500 17.918.198 20.573.008
501-1000 8.168,040 13.911.373
1001-3,300 22,973.634 34.824,676
3,301-10,000 23.676,791 39.999.667
10.001-50,000 24.199,442 46.144.477
50,001-100.000 7,757,091 13.473.336
100,001-1.000,000 9.619.194 16.026.923
Csp Coil
39.765.635
217,950.736
147.377.279
368.935,230
423,757.042
468.655.250
142.736.715
169,789.455
1.999,167.342
No. of Sites Above
Rag. Limit S
751
2,810
1,616
2,897
2,156
1,761
445
207
Annual Monitoring
Cot!
238.112
949.608
710,076
1.272.620
867,312
777,660
196,620
91,520
5,103,528
ToUl Annual
Coil
7,741.698
39.440.614
22.609.469
59.071.130
64.743.770
71,121.579
21,427.047
25,737.637
1312,093,364
Syitem Site 0»M Coil Annual Cap Csp Coil Annual
Cost Monitoring
Cost
WS S 21,668,369 24.326.602 257.716,371 1,187.720
VS J 31.161,674 48,736,248 516,312,510 1,982.696
S S 23.876.791 39,999.667 423.757.042 667.312
M i 31,956,532 59.617.613 631.591,965 674.280
L S 9.619.194 16.026.923 169.789,455 91.520
Total 1118.282,581 188.707,255 1,999,167.342 5.103,528
Tolll
i
47.182,712
61,660.619
64.743.770
92.546.626
25,737,637
» 312.093.W4
Monitoring Coil (or No. ol Sys. Cost par
yslams Abova Reg. Above Reg. System
Limit Limit
150.290 671 11.408
561,978 2,322 16.817
323.237 1.146 19.562
579.315 1,704 34,262
431,143 945 66.015
352.142 451 156.593
69.034 51 416.649
41,442 24 1.090.917
Syitem Site O»M Coil Annual Cap Coil No. of Sites Monitoring Coil No. of Sys. Costptr
Above Rag. for Systems Above Reg. System
Llmll Above Rag. Limit
Limit
WS 21.668,389 24,326.602 3.561 I 712.268 2.9932 15.605
VS 31.161.674 48.736.248 4,513 S 902,551 2.850.1 28.350
S 23.876.791 39,999,667 2.158 I 431.143 945.5 88.015
M 31,956.532 59.617.813 2.206 $ 441.176 5026 183.087
L 9.619.194 16.026.923 207 ( 41.442 235 1090917
Household Costs HH Consumption (gal): 03.000
System Size O»M Coil Annual Cap Monitoring Coit for Average Dally Flow No. of Sys. HH
Coil Syslema Above Reg. (MOD) Above Rag. Incremental
Limit Llmil Coil
25-100
101-SOO
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
3.750.191 $ 3.753,595
17,918.198 $ 20,573.008
8,166.040
22.973,634
23,876.791
24.199.442
7.757.091
9,619,194
13.911.373
34.624.676
39.999.667
46,144.477
13,473,336
16,026.923
150,290 00071 671
561.976 0.0346 2.322
323.237 0.0947 1,148
579,315 02505 1,704
431,143 0.8252 945
352.142 3.2049 451
89.034 11.1710 51
41.442 375902 24
364.62
11040
4898
31.11
18.74
1111
848
660
Syitem Size
WS
VS
S
M
L
DIM Cost
21.666,389
31.161.674
23.676.791
31.956,532
9.819.194
Annual Cap Cost Monitoring Average Dally Affected HH
Coil for Flow(MGD) Systems Incremental
Systems Cost
Above Reg.
Llmll
24.326.602 S 712.266 00285 2.9932 t 124.64
48,736.246 ( 902.551 0.1878 2.650.1 t 34.33
39,999,667 i 431,143 08252 945.5 S . 18.74
59.617.613 * 441,176 40168 $02.6 ( 10.37
16.026.923 a 41,442 375902 23.5 S 660
Dl-3
-------
Results (200 MCL)
PRIVATE
i Monitoring Cost*
Coil Frequency
Monitoring COM * so 4
System Site
25-100
101-500
501.1000
1001-3.300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
No. of Sites No. of
Systems
133168 11890
112578 9304
22560 1600
23052 1356
9438 414
846.3 217
200.1 23
114.4 13
Total Annual
Monitoring Cost
2.663,360
2.251.568
451.200
461,040
188,784
169.280
40,020
22,880
Cost per System
224
242
282
340
456
780
1,740
1.760
System Sire No. of Sites No. of Total Annual Cost per System
Systems Monitoring
Cosl
WS 245746 211940 $ 4,914,928 232
VS 45612 29560 t 912,240 309
S 943.9 414.0 $ 188,784 456
M 1046.4 240.0 $ 209,280 872
L 1144 130 $ 22.880 1.760
Totals
System Slu
25-100
101-500
501-1000
1001-3,300
3.301-10,000
10.001-50,000
50,001-100,000
100,001-1,000,000
Total
OiM Cost Annual Cap
Cosl
38,658,392 36.463.260
34.947,179 38,751,424
4.421.018 7.468.957
6,983,315 10,661.006
4.413.911 7.428,059
4,628,174 8.892.474
1.354.313 2,380.247
2.312,682 3,877.232
97.718.985 $115,922.659
Annual Cap Cost
386,292,293
410,533.140
79.126.237
112.942.846
78.692.959
94.206,999
25.216,374
41.075.451
1,228,086.298
Total Annual
Monitoring Cost
2,663,360
2,251,568
451,200
461.040
188.784
169,260
40,020
22,880
6,248.112
Total Annual
Cosl
77,765,011
75,950,171
12,341.175
18.105.361
12.030,753
13.689.908
3,774.581
6,212,794
$219,889,755
System Size OiM Cosl Annual Cap Cap Cost
Cost
WS $ 73.60S.57t $ 75.214,684 796,825,432
VS $ 11.404,334 $ 18.129,963 182.069,083
S $ 4.413.911 $ 7.428.059 78.692.959
M $ 5.982.487 $ 11.272,722 119.423,373
L $ 2,312.682 $ 3,877.232 41,075,451
Total $97.718,985 $115.922659 1,226.066.298
Annual
Monitoring
Cost
4.914.928
912.240
188.784
209,260
22.880
6.248.112
Total
i
153.735.183
30.448,537
12,030.753
17,464.489
6,212,794
$ : 219.B89.T6S
Per System Costs
System Size
2S-100
101-500
501-1000
1001-3,300
3.301-10.000
10,001-50,000
50,001-100,000
100,001-1,000,000 i
DIM Cost
38,658,392
34.947.179
4.421.018
6.983.315
4.413,911
4.628.174
1,354,313
2.312.682
Annual Cap No. of Sites Above
Cost Reg. Limit S
36.463.260 8.405
38.751.424 6,662
7,468.957 1,027
10.661.006 1,049
7.426.059 469
8,892,474 383
2,380.247 • 91
3,877.232 52 1
Monitoring Cost for No. of Sys.
ystems Above Reg. Above Reg.
Limit Limit
1,661,046 7.505
1.332.478 5.506
205.393 728
209.872 617
93,845 206
76.645 98
18,122 10
10.361 6
Cost per
Sytlem
10.234
13,627
16,807
28,924
57.997
138.377
360.318
1.053.270
System Site
WS
VS
S
M
L
OiM Cost
73.605.S71
11,404.334
4.413.911
5.982.487
2.312.682
Annual Cap Cost No. of Sites H
Above Reg.
Limit
75,214,684 15,088
18,129,963 2.076
7,428.059 469
11.272,722 474
3,877,232 52
lonitoring Cost No. of Sya.
for Systems Above Reg.
Above Rag. Limit
Limit
3.013,524 13,010.8
415,265 1.3456
93.84$ 2058
94.767 108.7
10,361 59
Cost per
System
11.870
22.257
S7.997
159.647
1,053.270
Household Costs HH Consumption (gal): B3.ooo
System Sin DIM Cost Annual Cap Monitoring Cost for Average Dally Flow No. of Sys. HH
Cost Systems Above Reg. (MGD) Above Reg. Incremental
Limit Limit Cost
25-100
101-500
501-1000
1001-3,100
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000.000
38.658.392
34,847.179
4.421,018
6,983.315
4.413.911
4.628,174
1,354.313
2,312,682
36,463.260
38.751.424
7,468.957
io.eet.ooe
7,428.059
8.892,474
2.380.247
3.877.232
1.681.048 0.0052 7,505
1,332,478 00216 5.506
205,393 0.0726 728
209.872 0.1922 617
93.845 0.6543 206
76.645 27355 9.8
18.122 91202 10
10.361 38.0777 8
449.78
14359
5203
3422
2016
11.50
898
664
System Site
OIM Cosl
Annual Cap Cost
Monitoring Average Dally Affected
HH
Coal for Flow (MGD) Systems Incremental
WS
VS
S
M
L
73.605.571
11,404,334
4.413,911
5.982,487
2.312,682
75.214.684
18,129,963
7,426,059
11.272,722
3,877,232
Systems
Above Reg.
Limit
3,013,524 0.0121 13,010.8
415,265 0.1274 1.345.6
93,845 0.6543 205.8
94,767 3.3474 108.7
10.381 36.0777 59
Cosl
219.00
38.71
20.18
10.85
8.84
-------
Results (MCL 3OO)
PUBLIC
Monitoring Costs
Monitoring Cost
System Size
25-100
101-500
501-1000
1001-3,300
3,301-10,000
10,001-50,000
$0,001-100,000
100,001-1,000,000
Cost
* 50
No. of Sites
1190.6
47480
3550.4
6363.1
4336.6
3888.3
983.1
457.6
Frequency
4
No. of
Systems
1063
3924
2518
3743
1902
997
113
52
Total Annual
Monitoring Cost
238,112
949,608
710,076
1,272,620
867,312
777,660
198,620
91,620
Cost par System
224
242
282
340
456
760
1,740
1,760
System Size
WS
VS
S
M
L
No. of Site!
59386
99135
4336.6
4871.4
457.6
No. of
Syslemi
4987
6261
1902
1110
52
Totil Annual
Monitoring
Coil
1.187.720
1,982,696
667,312
974,280
91.520
Cost per System
» 236
S 317
I 456
$ 878
$ 1,760
Totals
Sy«l«m Site
25-100
101-500
501-1000
1001-3,300
3,301-10,000
10.001-50,000
50.001-100,000
100,001-1,000,000
Toll!
O&M Cotl
2.781.592
13,844,424
6.020,317
16.886,904
13,830,541
15.639.920
4,681.259
6.045,177
79.730.134
Annuil Cap
Co»I
2,850.613
16.195.878
10.068,553
25,304.952
22,831.973
29,328.830
8,478.051
10.067.444
125.126.294
Cap Coil f
30.1S9.440
171.579.357
106.866.396
268.081.021
241,882,243
310.710.046
89,816,596
106.654,646
1.325.589.746
nnual Monitoring Coil
238.112
949.608
710,076
1.272.620
867,312
777.660
196,620
91,520
5.103.528
Total Annuil
Coil
5,870,317
30.989,909
18.798.948
43,464,476
37.329,826
45,746.410
13.555,931
16.204.141
Sa»,B59.8Sr
System Silt 01M Cott
WS $ 16.628.015
VS J 22.907,221
S S 13.630,541
M S 20.521.179
L $ 6,046.177
Toltl I 79.730.134
Annual Cap Ctp Coil
Coit
19.046.491 S 201.77S.787
35,373,505 S 374,747,417
22.831,973 I 241,882,243
37,606.882 i 400.528,643
10.067.444 i 106.654,846
125.126.294 t 1.325.589.748
Annuil
Monitoring
Coil
1,187.720
1,982.696
867,312
974,280
91.520
5.103.528
Tolil
•
36,860,226
60.263.422
37.329.826
59,302.341
18.204.141
mtm-m;
Per System Co«U
Syitem Silt
29-100
101-600
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
Household Costs
Syttim Slu
15-100
101-900
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
OHM Coil
2,781,592
13.844,424
6,020,317
18,886.904
13.630.541
15,639,920
4.881,259
6,045,177
Annuil Ctp
Coil
2,850,613
16.185,878
10,088.553
25.304,952
22,831,973
29,328,630
8.478,051
10,067,444
HH Consumption (gal):
O&M Coil
2,781.592
13,644,424
6,020.317
16.886,904
13,630.541
15.638.820
4,881.258
6,045,177
Annuil Ctp
Cost
2,850.613
16,195,678
10,068.553
25,304,952
22,831,673
29,328,830
8,478.051
10,087,444
No. of SKti Abova
Reg. Limit
578
2.237
1,178
2,112
1.231
1,113
282
131
83.000
Monitoring Coil for
Syltems Abova
Rag. Limit
115.846
447.487
235,668
422.371
246,109
222,681
56,302
26,206
Monitoring Coil for
Syltim* Above Rag.
Limit
115.848
447.487
235.668
422,371
246,109
222,881
56,302
28,206
Averaga Dally Flow
(MOD)
00071
00346
00947
0.2505
08252
32049
11.1710
37.5902
No. ofSyi.
Abova Rag.
Limit
517
1,849
838
1.242
540
285
32
15
No. of Syi.
Abova Rag.
Limit
517
1,849
836
1,242
540
285
32
15
Cost per
System
11.114
16,488
19,534
34,304
66.015
158.295
414,609
1.083.867
HH
Incramantal
Cost
355.24
10824
46.91
3115
18.74
11.23
644
6.56
Systam Size
WS
VS
S
M
L
System Size
WS
VS
S
M
L
OtM Coil
16.626.015
22.907.221
13.630.541
20,521,178
6,045.177
OtM Coil
16.626,015
22,907,221
13,630,541
20,521,179
6,045.177
Annual Cip Coil
19,046.491
35,373.505
22,831,973
37,806,882
10.067,444
Annuil Cip Coil
19.048.491
35.373,505
22,831.873
37.806,882
10,067.444
No. of Sllat
Abova Rag.
Limit
2.817
3.290
1.231
1.395
131
Monitoring
Cost for
Syatama
Abova Rag.
Limit
563.313
658,039
246,108
278,882
26.208
Monitoring Coat
for Systamt
Above Reg.
Limit
S S63.313
f 656.039
* 246.109
* 278,982
S 26,208
Average Dally
Flow (MGD)
00289
0.1878
0.8252
40158
37.5902
No. of Sys. Coil per
Above Reg. Syitem
Limit
2.366.2 15.314
2.0780 26.364
5387 68,015
317.8 164,389
149 1.083.867
Affected HH
Systemi Incremental
Coil
2.3662 I 12166
2.0780 1 3434
5397 t 16.74
3178 $ 10.44
149 S 656
01.5
-------
Results (MCL 300)
PRIVATE
Monitoring Costs
Colt Frequency
Monitoring Cott 1 so 4
System S(ff No. of Sites No. of
System*
25-100 133168 11690
101-500 112578 9304
501-1000 22660 1600
1001-3,300 23052 1356
3,301-10,000 9439 414
10,001-90,000 846.3 217
60,001-100,000 200.1 23
100,001-1,000,000 1144 13
Toltl Annuil
Monitoring Coil
2.683,360
2.251.588
461,200
481.040
188,784
169,260
40,020
22.880
Co«l fit System
224
242
282
340
456
780
1,740
1.760
Syitem Sin No. of Sites No. of
Systems
WS 24574.8 21194.0
VS 4661.2 2966.0
S 943.8 414 0
M 10464 2400
L 114.4 130
Totil Annuil
Monitoring
Coil
4,814.928
912,240
188.764
209,280
22.880
Coit per Syitem
232
309
4S6
872
1,760
Total*
Syitem Size
25-100
101-500
501-1000
1001-3,100
3,301-10,000
10,001-90,000
50,001-100,000
100,001-1,000,000
Totll
DIM Co.l
28.743,047
27.007.628
3.248.828
5.127.374
2,519.746
2,989.480
852,420
1,453,436
71.939,758
Annual Cap Annual Cap Cost 1
Cost
27,700.787 S 293,482,535
30.476.227 S 322.865,567
5.396.100 S 57.166,355
7,731,234 * 81.904.808
4.239.924 $ 44.917.815
5.647,942 S S9,634,3B2
1,498.108 S 15,870,877
2,436.641 S 2S.803.217
85.125.984 $ 901.825,676
otal Annual Monitoring
Coil
2.663.360
2.251.S68
451,200
461,040
188,784
169.260
40.020
22.8BO
6.248.112
Total Annual
Coil
59,107,194
59.735.421
9.093,929
13.319,649
8,948.454
8.806.682
2,390,548
3.911,957
.193,313,834
System Size
WS
VS
S
M
L
Total
OCM Coil
55.750.673
8.374.003
2,619,746
3.841,900
1,453,436
71.939.758
Annual Cap
Coil
58.177.015
13.127,334
4,239,924
7,146,050
2,435.641
85,125.984
Cap Coit
618,328,122
139.071,163
44.917.815
75,705.359
25,803,217
901,825.876
Annual
Monitoring
Coil
4,914.828
912,240
188.784
209.280
22.880
8.248,112
Total
118,842.815
22.413,577
6.948,454
11,197,231
3.911,957
•»W».8«B»4
Per System Costs
System Size
25-tOO
101-500
501-1000
1001-3,300
1,401-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
04 M Coil
28.743.047
27,007,626
3.248,629
5.127,374
2.519,746
2,989,480
852,420
1.453,436 )
Annual Cap No. of Sites Above
Coil Reg. Limit
27.700,787 6,479
30.476,227 5,305
5,398,100 749
7.731.234 765
4,239.924 268
5,647.942 242
1.498,108 57
2,435,641 33
Monitoring Cost for No. of Sys.
Systems Above Reg. Above Reg.
Limit Limit
1,295.779 5.765
1,060.987 4,384
149,749 531
153,015 450
53.569 117
48.467 62
11,460 7
6.552 4
Cost per
System
9.981
13.354
16.558
28.912
57,998
139.785
358,639
1.048,505
System Size OtM Cost
WS $ 55.750,673
VS S 8,374.003
S S 2.519.746
M S 3.841.900
L S 1,453.436
Annual Cap Cost No. of Sltta ft
Above. Reg.
Limit
58.177.01S 11.784
13,127,334 1.514
4.239.924 268
7.146.050 300
2.435.641 33
lonlloring Cost No. of Sys.
for Systems Above) Reg.
Above- Reg. Limit
Limit
2.358.74* 10.1989
302.764 981.1
63.689 117.5
59.827 68.7
6,552 3.7
Call per
System
11.435
22.22S
67,998
160.75*
1,046.S05
Household Cost* HH Consumption (gal): 83,000
System SUe O&M Cost Annual Cap Monitoring Cost for Average Dally Flow No. of Sys, HH
Cost Systems Above (MGO| Above Reg. Incremental
Reg. Limit Limit Cost
25-100
101-500
501-1000
1001-3,300
3,301-10,000
10,001-50,000
$0,001-100,000
100,001-1,000,000
26,743,047
27.007,626
3,248,629
5,127,374
2,518,746
2,989.480
852.420
1,453,436
27.700,787
30,476,227
5,396.100
7,731,234
4.239.924
5.647.942
1,496,108
2,436,641
1,295,778 00052 5.785
1,060.967 00216 4.384
149.749 00726 531
163.016 01922 450
53.569 06543 117
48.487 27355 62
11.480 91202 7
6.552 380777 4
438.67
140.71
5188
34.21
20.16
1162
894
660
System Slzo O1M Cost
Annual Cap Cost
Monitoring Average Dally Affected
HH
Cost for Flow(MGD) Systems Incremental
WS i 55.750.673
VS S 8.374.003
S $ 2,519,746
M t 3,841,900
L $ 1,453.436
58,177,015
13.127,334
4.239,924
7,146.050
2.435.641
Systems
Above Reg.
Limit
2.356.746 0.0122 10,1688
302,764 01274 981.1
53.589 06543 117.5
59,927 3.3474 687
6,552 38 0777 37
Cost
212.11
39 .68
20.16
10.82
660
D1-8
-------
Results (MCI. 40O>
PUBLIC
Monitoring COM*
Cost Frequency
Monitoring Cost * SO 4
System Sit* No. of Site* No. of
Systems
25-100 11908 1063
101-500 4748.0 3924
501-1000 3550.4 2518
10010,300 63831 3743
3,301-10,000 43366 1S02
10,001-50,000 38863 897
50,001-100,000 883.1 113
100,001-1,000,000 457.6 52
Tolil Annuil
Monitoring Coil
t 238,112
t 949.608
^ 710,076
1,272.620
867.312
777,660
198,620
91.520
Coil p»r System
224
242
282
340
458
780
1,740
1,760
System Size No. of Sit** No. ol Tolil Annul!
Systems Monitoring
Cost
WS 5938.6 4987 I 1,187.720
VS 98135 6261 t 1,982,696
S 43366 1902 * 867,312
M 48714 1110 J 974.280
L 457.6 52 * 91.520
Cost per System
238
317
456
878
1,780
Totals
System Slie
25-100
101-500
501-1000
1001-3,300
3.301-10,000
10.001-50.000
$0,001-100.000
100.001-1,000,000
Told
OlM Cost
2.123.221
11.056.424
4.603.019
12.911.775
8.824.225
10.411.672
3.192.376
3.941.971
57.064.684
Annual Cap
Cost
2.253.189
13.283.448
7.547.858
19.039.942
14.697.410
19,322.808
5.544,352
6.557.905
88.246.893
Cap Cost
23,870,107
140.725,040
79,962,119
201,709,414
155704,574
204,706.101
58,736.948
69.474,539
934.888.843
Annual Monitoring
Cost
238.112
949.608
710.078
1.272.620
867,312
777,660
196.620
91.520
5.103.528
Total Annual
Cost
4.614,502
25,289,480
12.860.953
33.224,336
24,388,948
30.512,140
8,933,349
10,591.396
I1S0.415.108
System Site
WS
VS
S
M
L
Tola!
OlM Cost
13.179.645
17,514,794
8.824.225
13,604.049
3.941.971
57.064,684
Annual Cap
Cost
15.536.617
26.587,800
14.697.410
24.867,160
6,557.905
68,248.893
Cap Cost
164.565.147
281.671,533
155.704.574
263.443,049
69.474,539
934,888.843
Annual
Monitoring
Cost
1.187.720
1.982.693
867.312
974,280
91,520
5.103.528
Total
•
29803,983
46.085.290
24.388.848
39,445,489
10.591,396
l'lso.4is:i<)a
Per System Costa
System Site
25-100
101-500
501-1000
1001-3,300
3,101-10,000
10,001-50,000
50,001-100.000
100,001-1,000,000
Household Costs
System Site
25-100
101-500
501-1000
1001O.100
3.301-10.000
10.001-50,000
50,001-100,000
100,001-1,000,000
O&M Cost
2,123,221
11.056.424
4,603.019
12.911.775
8.824.225
10.411.872
3,192.376
3.941.971
Annual Cap
Cost
2,253,169
13,283.448
7.547.858
19.039.942
14.697.410
19.322.808
$ 5,544.352
S 6.557.905
HH Consumption (gal):
OlM Cost
2,123,221
11.056,424
4.603.019
12.911.775
8.824.225
10.411.672
S 3.192.376
S 3.941.971
Annual Cap
Cost
2,253.169
13.283.448
7,547.858
19,039.942
14.697,410
19,322.808
5.544,352
6,557,905
No. of Sites Above
Reg. Limit
465
1.858
891
1.597
794
736
186
87
83.000
Monitoring Cost for
Systems Above Reg.
Limit
93.039
371.679
178.164
319.311
158.767
147.251
37.230
17.329
Monitoring Cost for
Systems Above Reg.
Limit
93.039
371.679
178.164
319.311
159.767
147,251
37,230
17.329
Average Dally Flow
(MGD)
00071
00348
0.0947
0.2505
0.8252
32049
11.1710
37.5902
No. of Sys.
Above Reg.
Limit
415
1,538
632
939
348
189
21
10
No. of Sys.
Above Reg.
Limit
415
1.536
632
939
348
189
21
to
Cost per
System
10,761
16,090
19.515
34.362
68.013
158,286
410.061
1.068.141
System Slie
WS
VS
S
M
L
HH 1
Incremental
Coil
34393
10562
4886
31.20
18.74
1123
8.35
6.48
Syitem Size
WS
VS
S
M
L
OlM Cost
13,178,645
17.514.794
8.824.225
13.604.049
3.941,971
OiM Cost
13.179,645
17,514,794
8,824.225
13.604.049
3,941.971
Annual Cap Coil
15,536.617
26.587,800
14.697,410
24.867,180
6.557.905
Annual Cap Cost
S 15.536,617
S 26,587.800
( 14,697.410
t 24.867.160
t 6.557.905
No. of Silas
Above Reg.
Limit
2,324
2,487
794
922
87
Monitoring
Cost tar
Systems
Above Reg.
Limit
» 464.719
* 497,476
> 158.767
I 184.461
* 17,329
Monitoring Coat
for Systems
Above Reg.
Umll
464.719
497.476
158.767
184.481
17,328
Average Dally
Flow (MGD)
00288
01878
0.6252
40158
375902
No. of Sya. Coal per
Above Reg. System
Llmll
1.851.2 14.955
1.570.8 26.381
348.2 68.013
210.2 183,917
8.6 1.086.141
Affected HH
Syatems Incremental
Coal
1,951.2 ( 11816
1,570.8 t 34.37
3482 t 1874
210.2 t 10.41
88 S 6.46
01-7
-------
Results (MCL 400)
PRIVATE
Monitoring Coiti
Coit Frequency
Monitoring Cost $ so 4
System Sin No. ot Sltet No. of
Systems
25-100 13318.8 11890
101-900 112578 9304
501-1000 22660 1600
1001-3.300 23052 1358
1.301-10,000 943.9 414
10,001-50,000 846.3 217
$0,001-100.000 2001 23
100,001-1,000,000 1144 13
ToUl Annual
Monitoring Co»l
2.883.300
2,291.668
461.200
481.040
188.784
189.280
40,020
22.880
Cott per System
t 224
t 242
262
340
456
760
1.740
1,780
System Size No. of Sites No. of Totil Annual
Systemt Monitoring
Coil
WS 245746 21194.0 t 4,914.928
VS 45812 26560 * 912.240
S 9439 4140 I 188.784
M 10484 240.0 S 209.280
L 1144 130 % 22.880
Cost per System
232
309
458
872
1,760
Total*
Syttem Size
25-100
101-500
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
Total
01M Coil
22.013,510
21.574.817
2,478,244
3,914,358
1.630.523
1,989.875
557,784
947,812
55,108.923
Annual Cap
Cotl
21.902,572
24,962.770
4,034,934
5.800,736
2.727,989
3,720,311
980.223
1.588,757
65.716.292
Annual Cap Coat
232,036.155
264.456,940
42,748,149
61,453.060
28.900.356
39.413,033
10.364,492
16.810.123
696,199.331
Total Annual
Monitoring Cott
2.663.360
2,251.588
451.200
461.040
186.764
169.260
40.020
22.860
6.246,112
Total Annual
Cost
46,579,441
46.769.155
6,984.376
10,178.134
4.547.296
5.879.448
1.578.027
2.567.449
J127.071.328
Syttem Size
WS
VS
S
M
L
Total
OiM Cost
43,688,327
8.392.802
1,630.623
2.547,659
947.612
55.108.923
Annual Cap
Cost
46.885,341
9.835.670
2.727.969
4,700.534
1.586,767
65,718.292
Cap Cott
496.492.095
104,199,230
28,900.356
49.797,525
16.610,123
696.199.331
Annual
Monitoring
Coit
4.914,928
812.240
188,784
209.280
22.680
8,248.112
Total
,
9S.368.S97
17.140,512
4.547.296
7,457,473
2,557.449
frlJ7,071.3Z6
Par Sy»t«m CosU
Syittm Size OIM Coit Annual Cap No. of Sites Above Monitoring Cott for No. of Syt . Cotl per
Cot 1 Reg. Limit Systemt Above Re0. Above Reg. System
Limit Limit
25-100
101-500
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
22,013,510
21.574.817
2.478.244
3.914,358
1.830,523
1,989,876
557,784
947,812
21,902.572 5,203
24,962,770 4,406
4,034,934 566
5,600,738 678
2,727,989 173
3,720.311 160
980,223 38
1,586.757 22
1.040,675 4,848
881,270 3,642
113,210 401
115,879 340
34,556 76
32,060 41
7,578 4
4,332 2
9,677
13,021
16.506
28,894
57.967
139.750
354,692
1,031,416
System Site OiM Cott Annual Cap Cott No. of Sllat Monitoring Cotl No. of Syt. Cott fu
Above Reg. for Syatema Above Reg. System
Limit Above Reg. Limit
Limit
WS
VS
S
M
L
43,566,327
6.392,602
1,630.623
2,547,659
947.612
46,865.341 9,610
9,835,670 1,144
2.727,989 173
4,700,534 198
1.566,757 22
1.921,945 6.2675
228.689 741.7
34.558 75.8
39,627 45.4
4.332 26
11.146
22,169
57.967
160,368
1.031.418
Household CosU HH Consumption (p»l):
63.000
System Size
25-100
101-500
501 -1000
1001-3,300
3,301-10,000
10,001-50.000
50,001-100,000
100,001-1,000,000
OiM Cott
22.013.510
21.574.817
2.478.244
3,914,358
1,630.523
1.989.875
557.764
947,812
Annual Cap
Cotl !
21,902,572
24,962,770
4.034,934
5,600,738
2.727.989
3.720.311
980.223
1,586,757
Monitoring Cott for Average Dally Flow No. of Syt.
iyttemt Above Reg. (MOD) Above Reg.
Limit Limit
1,040.675 00052 4.648
881.270 00218 3,642
113,210 0.0726 401
1)5,879 0.1922 340
34,556 0.6543 76
32.060 2.7355 41
7.S78 9.1202 4
4,332 380777 2
HH
ncremenlal
Cost
42528
137.21
51.72
34.19
2015
1162
8.85
650
System Size
WS
VS
S
M
L
OSM Cott
43,688.327
8.392,602
1.630.523
2.547.659
947.612
Annual Cap Coat
46.865.341
9,635,670
2.727.969
4.700.534
1.686.757
Monitoring Average Dally Affected
Cost for Flow (MQD) Systems
Systems
Above Reg.
Limit
1,921,945 0.0124 8,287.5
228,889 01274 741.7
34,558 0.6543 758
39.627 3.3474 4S.4
4,332 36.0777 2.5
HH
ncremenUI
Cott
204.ee
3969
20.15
1089
660
D1-8
-------
Results (MCL 600)
PUBLIC
Monitoring Co*u
Coil Frequency
Monitoring Cost * so 4
System Sin
25-100
101-500
901-1000
1001-3,100
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
No. of SltM
1190.6
4748.0
35604
6363.1
4336.6
36863
983.1
457.6
No. of
Syelema
1063
3924
251 B
3743
1902
997
113
52
Toltl Annual
Monitoring Cot!
238,112
940.608
710.076
1,272.620
867.312
777.660
$ 196,620
f 91,520
Coil per System
224
242
282
340
456
780
1,740
1.760
System Sl»
WS
VS
S
M
U
No. of SUM
69386
99135
43366
4871.4
4576
No. of
Sy«l*m>
4987
6261
1902
1110
52
Toll! Annual
Monitoring
Cost
t 1.187.720
I 1,982,696
t 867.312
I 974.280
I 91.520
Coil par System
$
i
s
s
$
238
317
458
878
1.760
Total*
Syalam Sla
25-100
101-500
501-1000
1001-1,300
3,301-10.000
10,001-50,000
50,001-100,000
100,001-1,000.000
Total
O1M Coil
1,732,298
9.357,761
3,582,267
10.045.688
5.976.441
7,298.690
2,204.528
2.721.497
42.919.170
Annuil Cap
Coil
1.856,563
11,323.808
5,848.022
14.775.733
9.959.378
13.418.547
3.826.689
4,527.109
65.535,851
Cap Coal
19.688.458
119.964.588
61.932.844
156.534.329
105.509.795
142,156,277
40.581, 187
47.960,257
694.267.734
Annual Monitoring
Coil
238,112
949,608
710.076
1.272.620
667.312
777.660
196,620
91.520
5.103,528
Total Annual
Coil
3.826.973
21.631.177
10,138,365
26.094.042
16,803,131
21.494,897
6.229.837
7,340,126
(113,658,549
Syilem Site
WS
VS
S
M
L
Total
OlM Coil
11,090.058
13.627.956
5,976.441
9.503.218
2.721.497
42.919.170
Annual Cap
Coat
13,180.372
20.621.756
9.959,378
17.247.236
4,527,109
65,535.851
Cap Cott
139.633.046
218.467,173
105.509.795
182,717.464
47.960,257
694.287.734
Annual
Monitoring
Coal
1,187,720
1.962,696
867.312
974.280
91.520
5,103,528
Tola)
|
2S.458.1SO
36.232,407
16.803,131
27,724.734
7,340.126
* '113,598,649
Par System Co»U
System Slia
25-100
101-500
901-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000.000
Houaahold Cot U
System Sli*
25-100
101-500
S01-10OO
1001-3,100
3,301-10,000
10,001-50,000
50,001-100,000
100.001-1,000,000
DIM Cost
1,732,298
9.357,761
3,582,267
10.045,688
5.976,441
7,298.690
2,204.528
2.721.497
Annual Cap
Coal
1.856.563
11.323.808
5,846,022
14,775.733
9,959,378
13,418.547
3.828,689
4.527.109
HH Consumption (gal):
OtM Cost
S 1,732,298
9.357.761
3.582,267
10,045,688
5.976,441
7.298,690
2.204.528
2.721.497
Annual Cap
Cost
1.658.583
11,323.608
5.846,022
14,775,733
9.959,378
13.418.547
3,828,689
4.527.109
No. of Sites Abova Monitoring Cos! for
Rag. Limit Systems Abova Reg.
366 «
1,592 S
692 S
1,240 t
538 *
509 f
129 S
60 $
83.000
Limit
77,223
318,330
138.367
247.988
107,564
101.779
25.733
11,978
Monitoring Cost for Average Dally Flow
Systems Above
Reg. Limit
t 77,223
$ 318,330
t 138,367
S 247.966
J 107.564
t 101.779
t 25.733
» 11,976
|MGD)
00071
00346
0.0947
0.2505
08252
3.2049
11 1710
37.5902
No. of Sys.
Abova Rag.
Limit
345
1.315
491
729
236
130
15
7
No. Ol Sys.
Above Rag.
Limit
345
1.315
491
729
236
130
15
7
Cost par
System
10,634
15.964
19,497
34,371
88.013
159.550
409.665
1,066,840
System Size OJ.M Cost
WS 11.090.058
VS 13,627.956
S 5.976.441
M 9.503.218
L 2,721,497
__ . .
Incremental
Cost
339.89
10480
4882
3121
1874
11 32
834
645
System Size OlM Cost
WS 11,090.058
VS 13.627.956
S 5,976.441
M 9,503,218
L 2.721.497
Annual Cap Coil
13.180.372
20.621.756
9.959,378
17.247.238
4.627.109
Annual Cap Cost
13,180,372
20,621,756
9.959,378
17,247.236
4.527.109
No. of Sites
Abova Rag.
Limit
1,976
1,932
538
639
60
Monitoring
Cost for
Systems
Abova Rag.
Limit
S 395,553
t 386,354
* 107,564
« 127,513
S 11,878
Monitoring Cost
for Systems
Abova Rag.
Limit
S 395.553
* 366,354
t 107.564
t 127.513
$ 11,978
Average Dally
Flow (MGO)
0.0289
0.1678
0.6252
4.0158
375902
No. of Sys. Cost par
Abova Rag. Syalam
Limit
1,660.2 f 14.858
1.220.0 $ 28,389
2359 S 68,013
1453 t 185.014
6.6 t 1,066,840
Affected HH
Systems Incremental
Coal
1,6602 $ 116.81
1,2200 S 34.37
2359 ( 1874
1453 $ 10.48
68 t 8.45
01-9
-------
Results (MCL 500}
PRIVATE
Monitoring Costs
Coit Frequency
Monitoring Cost $ so 4
System Slz,e No. of Shea No. of
Systems
25-100 133188 11890
101-500 112578 9304
501-1000 2256.0 1600
1001-3,300 230S.2 1358
1,301-10,000 943.9 414
10.001-60,000 846.3 217
50,001-100,000 200.1 23
100.001-1.000,000 114.4 13
Total Annual
Monitoring Coat
2,663,380
2,251.568
451.200
461,040
188,784
169,260
40.020
22,880
Coat per System
224
242
262
340
456
780
1.740
1.760
System Size No. of Sites No. of
Systems
WS 24574.8 211940
VS 45612 29560
S 9439 4140
M 1046.4 240.0
L 114.4 130
Total Annual
Monitoring
Cost
4,914.928
912.240
188.764
209,260
22.880
Cost per System
232
309
456
872
1.760
Totals
System Slio
25-100
101-500
501-1000
tOOt-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000 J
Total
O*M Cod
17,981,153
18.261,847
1,928.127
3.044.728
1.104.360
1.394.415
365.201
654.362
44,754,193
Annual Cap
Coit
18,050,439
21.272.015
3.123,830
4.499.552
1.648,645
2.582.319
676,929
1,095,394
53,149,123
Annual Cap Cost
191,226.807
225.356,026
33.093,898
47.668,3 17
19,584,574
27,357.123
7.171,393
11.604,622
563,062.562
Total Annual
Monitoring Cost
2,663.360
2.251,568
451,200
461,040
188.764
169.260
40,020
22.880
6,248,112
Total Annual
Cost
38,694.952
41.785.430
5,503,157
8.005.320
3,141,789
4.145,994
1,102,149
1.772.637
ii«4;m«27
System Size OsM Cost
WS S 36.243.000
VS $ 4,972.855
S »• 1.104.360
M S 1,779,615
L S 654.362
Total t 44.754.193
Annual Cap
Coil
39,322.454
7.623,382
1.848.645
3.259,248
1,095.394
S3.149.123
Cap Coal
418,582,834
80.762.218
19.584.574
34.528.517
11.604.622
563.062.S62
Annual
Monitoring
Cod
4.914,928
912.240
188.784
209.280
22.680
6,248,112
Total
•
80,480,381
13.508,477
3,141,788
5.248.143
1.772.637
•t^mmm-.
Par System Costs
Syalem Sin OJ.M Coat Annual Cap No. of Silea Above Monitoring Cod for No. of Sya. Coat per
Coat Reg. Limit Syalema Above Reg. Above Reg. System
Limit Limit
2MOO
101-500
SOI-1000
1001-3,300
3,301-10,000
10,001-50,000
17,981,153
18,281,847
1,928,127
3,044.728
1,104,360
1,394,415
iO.OOt-100,000 I 385,201
100,001-1,000,000 I 654.362
18,050.439 4.319
21,272,015 3,774
3,123.830 440
4.499,552 449
1,848,845 117
2,562,319 111
676,929 26
1,095,394 15
883,768 3,856
754.778 3.119
87.922 312
89.840 264
23,413 51
22.153 28
5,238 3
2.995 2
9,568
12,918
16.486
28.891
57.970
140,802
354.582
1.030,168
System Site OtM Cod Annual Cap Coat No. of Sltea Monitoring Coat No. of Sya. Coat per
Above Reg. for Systems Above Reg. Syalem
Limit Above Reg. Limit
Limit
WS
VS
S
M
L
36,243,000
4,972,855
1.104.360
1,779,615
654.362
39.322.454 8.093
7,623.382 889
1.846,645 117
3.259.248 137
1.095.394 15
1.618,545 6,9750
177,762 578.0
23,413 51.3
27,390 31.4
2.995 1.7
11.066
22,177
67,970
161.290
1.030.168
Household Costs HH Consumption (gal):
63,000
System Size
2S-100
101-500
601-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
OtM Cod
17,981.153
18.281,847
1,928.127
3,044,728
1.104.360
1,394.415
38S.201
854.362
Annual Cap 1
Coal
18.050,439
21,272,015
3,123,830
4,499.552
1,848,645
2,582,319
676,929
1.095.394
Monitoring Coit for Average Dally Flow No. of Sya.
Systems Above (MGO| Above Reg.
Reg. Limit Limit
863.768 0.0052 3.856
754,776 0.0216 3,119
67,922 00726 312
89,840 0.1922 264
23.413 06543 51
22.153 27355 28
5,238 9.1202 3
2,995 360777 2
HH
ncremenlal
Coat
42051
136.11
51.65
34.19
20.15
11.70
8.84
6.49
System Size
WS
VS
S
M
L
OtM Cost Annual Cap Coit
36.243,000 S 39.322,454
4,972,855 S 7.823.382
1,104.380 S 1,848,645
1,779.615 S 3.259,248
654.362 S 1,095,394
Monitoring Average Dally Affected
Coal for Flow (MOD) Syatema
Syatema
Above Reg.
Limit
1,618,54$ 00125 4,975.0
177,782 0.1274 578.0
23.413 0.6543 513
27,390 33474 31.4
2,995 360777 1.7
HH
ncremental
Coal
201.14
38.57
20.15
10.98
649
01-10
-------
Results (700)
PUBLIC
Monitoring Coils
Can Fraqinncy
Monitoring Cost $ so 4
Syit«m Sift No. of Silai No. of
Syilams
25-100 11806 1083
101-900 4748.0 3824
501-1000 35504 2518
1001-1,300 6383.1 3743
3,101-10,000 4330.6 1902
10,001-50.000 38863 897
50,001.100,000 983.1 113
100,001-1,000,000 4576 52
Total Annual
Monitoring Co»t
238,112
948,608
710,076
1,272,620
867,312
777,660
196,820
91.520
Coit par Syitom
224
242
282
340
456
780
1,740
1,780
Sy«Iem Slza No: of Sllei No. of
Syltami
WS 69386 4987
VS 9913.5 6261
S 433S.6 1902
M 4871.4 1110
L 457.6 52
Total Annual
Monitoring
Coil
1,187,720
1.882,696
867.312
874,280
91.520
Coil par Syltim
238
317
4S6
678
1,760
Totals
Syitom Slza
25-100
101-900
501-1000
1001-3,100
3,301-10,000
10,001-50,000
50.001-100,000
100,001-1,000,000
Toll)
O&M Coil
1.229.539
7.111,247
2.307, 150
6.471,376
3,150.662
3.832.684
1,169.583
1.442.626
26.714,669
Annul) Cip
Coit
1,353.177
8,770.741
3.745.069
9,467.629
5.247.074
7,093.943
2.031,223
2.399.020
40.107.896
Cip Coit
14.335.560
82.817,353
39,675,523
100.300.199
55,587.574
75.153.333
21.518.804
25.415,256
424.903,620
Annuil Monitoring
Coit
238.112
949,60B
710.076
1,272.620
887,312
777.660
196.620
81,620
5.103,528
Total Annual
Coit
2,820,828
16.831.596
6.762.315
17,211,627
9.265.068
11.704,287
3.397.426
3,933.166
W.WHM*
Syitam Slza O*M Coit
WS ( 8.340.786
VS S 8,778,529
S * 3.180.682
M t 5.002.267
L * 1.442,626
Total S 26.714.889
Annual Cap
Coil
10.123.816
13,212.718
5.247.074
9,125.166
2.399,020
40.107.896
Cip Coit Annual
Monitoring
Colt
107,252.933 $ 1.187.720
139.875.721 t 1,862,696
55.567.574 t 667.312
96.672,137 S 874,280
25.415.256 S 91.520
424.903.620 t 6,103.528
Totil
19.6S2.424
23.973,942
8.265.068
15,101,713
3.833,168
t smwawa1
For System Costs
Syitam Slza
29-100
101-500
501-1000
1001-3,300
3.301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
O&M Coit
1.229.539
7.111,247
2.307,150
8,471.378
3,150.682
3,832.684
1,169,583
1.442,626
Annuil Cap No. of Sllaa Abovi Monitoring Coil (or No. olSyi.
Coit Rag- t-lmll Syltami Abovi Rag. Abova Rag.
Limit Limit
1,353,177 284 I 56.802 254
8,770,741 1.241 $ 248,279 1,026
3,745,089 444 S 88.801 315
9,467.629 796 $ 159.152 468
5.247.074 283 ) 58,684 124
7.093.943 271 I 54.188 68
2,031.223 68 t 13.696 8
2.399.020 32 $ 6,375 4
Coil par
Syilam
10.409
15,722
19,502
34,391
68,013
158,118
408,394
1,082.375
Syitam Slz«
WS
VS
S
M
L
OSM Coit
8.340.786
6.778.529
3,150,682
5,002,267
1.442.626
Annual Cap Coit No. of SUM 1
Abova Rag.
Limit
10.123.918 1,525
13.212.718 1.240
5,247,074 263
9.125.166 339
2,399,020 32
Donilortno Coil No. ofSyi. Coil par
for Syilami Abov* Rag. Syitam
Abova Rag. Limit
Limit
305,081 1.2795 S 14.009
247.854 7830 S 28.403
56.684 1243 $ 68.013
67,864 77.3 $ 183,597
6.375 3.6 $ 1,062.375
Household Costs HH Consumption (gal): 63,000
Syatam Si» O&M Coil
25-100 I 1.229,539
101-500 * 7.111.247
501-1000 * 2.307,150
1001-3,300 t 6.471.378
3,301-10,000 1 3,150.682
10,001-50,000 S 3.832,684
50,001-100,000 $ 1,169.583
100.001-1,000.000 S 1.442.626
Annual Cap
Coit
1,353.177
8.770,741
3,745,089
9.467,629
5,247.074
7.093,943
2.031.223
2.399,020
Monitoring Coit for Avaraga Dally Flow No. of Syi.
Syilamt Abova (MGD) Abova Rag.
Rag. Limit Limit
56,802 0.0071 254
248.279 00346 1,026
88.801 0.0947 315
159,152 02505 488
58,684 08252 124
54,168 32049 69
13,696 11.1710 8
6,375 375902 4
HH
ncremanlal
Coit
332.69
103.21
4683
31.22
18.74
1122
8.31
643
Syitam Slza
WS
VS
S
M
L
OSM Coil
8,340,786
8.778.529
3,150,682
5.002,267
1,442,626
Annuil Cap Coil Monitoring Avarag* Dally Affected HH
Coal for Flow (MGD) Syalami Incramanlal
Syilami Coit
Abova Rag.
Limit
10,123,918 t 305.061 00292 1,279.5 f 11430
13.212.718 S 247,854 Q.I 678 7830 t 3439
5.247,074 S 56,684 08252 1243 I 1874
9,125,166 S 67,664 40158 773 t 1040
2,399,020 J 6.375 37.5802 36 « 643
D1-11
-------
Results (700)
Prtvatt
Monitoring Cost*
Coil Frequency
Monitoring Cost $ so 4
Syilem Slie No. of Site* No. of
Syilemi
29-100 13318.8 11690
101-500 112578 8304
901-1000 22560 1600
1001-3.300 2305.2 1354
3,301-10,000 843.9 414
10,001-90.000 848.3 217
90,001.100,000 2001 23
100,001-1,000,000 114.4 13
Told Annutl
Monitoring Coil
2,683.360
2.251.568
451.200
461,040
188.784
169,260
1 40,020
( 22,880
Co»l per Syliem
224
242
282
340
466
780
1,740
1.760
Syitorn Slu No. of SUM No. of
Syitemi
WS 24574.8 21194.0
VS 4561.2 2956 0
S 843.8 414.0
M 10464 240.0
L 114.4 <3.0
Totil Annul)
Monitoring
Cost
4.814.828
812.240
188.784
209,200
22,880
Cod per Syitem
232
309
456
872
1,760
Totals
Syitem Slu
J5-100
101-900
501-1000
1001-3,300
3,301-10,000
10.001.50,000
90.001-100,000
100,001-1,000,000
Totil
DIM Colt
12.794.447
13.880,285
1.241.160
1,960,400
582,171
732.501
204.394
346.873
31.742,231
Annual Cip
Coil
13.158.675
18.461.517
1.999.496
2,680.358
873.900
1.365.811
359.183
580.485
37,779.435
Annuil Cip Coil
139.403.188
174.393.548
21,182.684
30,514.556
10.317,515
14,469,423
3.805.191
6.149.770
400,235,874
Tola! Annuil
Monitoring Coil
2.663.360
2,251.568
451.200
461.040
188.784
169,260
40.020
22.680
8,248.112
Totil Annuil
Coil
26.616.482
32.593.370
3.691,855
5.301,709
1,744.856
2,287.572
603.597
950.248
»C7S,7»977»
Syitem Sin
WS
VS
S
M
L
Totil
DIM Coil
26,674,732
3,201,560
582.171
936.895
346.873
31,742.231
Annuil Cip Cip Coil
Coil
29.620,192 S 313.796,736
4,879.854 S 51,697,239
9/3.800 S 10.317,515
1,724,994 f 18,274,614
580.495 t 6.149,770
37.779,435 S 400.235.874
Annuil
Monitoring
Coil
4.914,928
912,240
188.784
209,280
22,880
6.248.112
Toll!
61,209,652
8.993.6S4
1.744.856
2.871.169
950.246
l?ft7(K700.T79!
Par System CoiU
Syitim Sl» O&M Coil Annuil Cip No. of Silil Above Monitoring Colt for No, of Syi. Coil per
Cott Reg. Limit Syitemi Abovi Rig. Above Reg. Syitem
Limit Limit
99-100
101-900
901-1000
1001-3,300
3,301-10,000
10,001-90,000
90,001-100,000
100,001-1,000,000
12.784,447
13.880,285
1,241,160
1.960.400
582.171
732.501
204.394
346,673
13,158.675 3.177
16.461.517 2,943
1.999,496 282
2.880,358 238
973,900 62
1.365,811 59
359,183 14
580,495 8
635.348 2.836
588.681 2,433
56.427 200
57.657 170
12.338 27
11.790 15
2,768 2
1.594 1
8,374
12,715
16,478
28,886
57.967
139,601
353,519
1.025.884
SyilemSlie OJM Coil Annuil Cip Coil No. of Site* Monitoring Coil No. ofSyi. Coitper
Above R«g. for Syeteme Above Reg. Syitom
Limit Abov* Rig. Limit
Limit
WS
VS
S
M
L
26.674.732
3,201.560
582,171
836.885
346.873
29,620,182 6,120
4,879,854 £70
973,800 62
1,724,894 73
580,495 8
1.224.027 6,268.8
114.084 368.7
12,338 27.1
14.676 16.7
1,584 09
10.917
22.170
57.867
160.101
1,025.884
Household Cost* HH Consumption (gal):
83.000
Syitem Sin
29-100
101-500
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
O&M Coil
12,794,447
13,860,285
1,241.160
1,960.400
582,171
732,501
204,394
346,873
Annuil Cip
Coil
13,158,675
16,461,517
1,999,496
2,680,358
973.900
1.365.811
359.183
S60.495
Monitoring Coil for Average Dally Flow No. of Syi.
Syitemi Abov* (MOD) Above Reg.
Rog. Limit Limit
635,346 0.0052 2,636
588,681 0.0216 2.433
56,427 0.0728 200
57,657 0.1922 170
12.338 06543 27
11,790 27355 15
2.788 9.1202 2
1.584 38.0777 1
HH
ncremenlil
Coil
411.69
13398
5163
34,18
20.15
11.60
8.81
647
Sytlem Sin
WS
VS
S
M
L
DIM Cost
26,674,732
3.201.560
582,171
936,895
346.873
Annuil Cip Coil
29,620.192
4.879.654
973.900
1,724.994
580.495
Monitoring Average Dilly Affected
Coil for Flow |MGD| Sytlemi
Syitemi
Above Reg.
Limit
1,224,027 0.0127 5,268.9
114.084 0.1274 369.7
12,338 06543 27.1
14,57« 3.3474 16.7
1,594 36.0777 08
HH
ncrementil
Coil
19472
39.56
20.1S
1066
6.47
DM2
-------
Results (1000 MCL)
PUBLIC
Monitoring Com
Cotl Frequency
Monitoring Cost I so 4
Syitem Slif No. of Sltei No. of
Syitoma
25-100 1190.6 1063
101.500 4746.0 3924
501-1000 3550,4 2S1B
1001-3,300 6363.1 3743
3.301-10.000 . 4336.6 1902
10.001-50,000 3888.3 997
Toll) Annuil
Monitoring Coil
238.112
949.606
710,076
1.272,620
667,312
777,660
50.001-100,000 983.1 113 $ 196.620
100,001-1,000,000 4576 52 > 91,620
Coil per Syilem
224
242
282
340
456
760
1.740
1.760
Syilem Size No. of Sllai No. of Total Annual Cotl per Syiltm
Syilemi Monitoring
Coil
WS 59386 4967 * 1,167,720 238
VS 99135 6261 * 1.982,696 317
S 43M6 1902 $ 867,312 45S
M 4671.4 1110 $ 974.280 878
L 457.8 52 { 91.520 1,760
Touts
Syitem Sli« DIM Coil Annual C»p
Coil
25-100 $ 626.364 S 927,172
101-500 5,237,370 $ 6.561.310
501-1000 1.341,182 J 2.162,218
1001-3,300 3.760.133 t 5,483.001
3,301-10,000 1.557,443 2,592,421
10.001-50,000 1.650,358 3.356,666
50,001-100,000 546,765 949,562
100,001-1,000,000 674.093 1.120.795
lotil 15.793.712 23.153.144
Cap Coit
9,622.476
69.510,616
22.906.551
56.066,995
27.464.147
35.560,564
10.059.669
Annual Monitoring
Coil
238,112
949.608
710.076
1.272.620
867.312
777.660
196.620
11.673.716 $ 91,520
246.284,735 $ 6.103.S28
Total Annual
Coil
1,991,646
12.746.295
4.213.475
10,515.754
5,017,176
5,984,682
1.692.947
1.666.407
44,050.384
Sytl«Ri Sin O&M Coil Annual Cap Cap Coil
Coil
WS 6,063.740 7.468.483 79.333.092
VS 5.101,315 7,645.218 80,993,546
S 1.557,443 2.592,421 27.464,147
M 2.397,121 4,306.227 45.620.234
L 674.093 1.120,795 11.873,716
Total 15.793.712 23.153.144 245,284,735
Annual
Monitoring
Coil
1,187.720
1,982.696
667.312
974,280
91.520
5.103.526
Total
14,739.943
14,729.229
5,017,178
7.677,629
1.686.407
wmmiw
Per System Costa
Syil«mSI» DIM Cost Annual Cap No. of Sltei Abov* Monitoring Coil for No. ofSyi. Coil par
Coil Reg Limit Syitemi Above Reg. Above Reg. Syilem
Limit Limit
25-100 S 826.364
101-500 $ 5.237,376
501-1000 * 1,341,162
1001-3.300
3,301-10.000
10,001-50,000
50,001-100.000
100,001-1,000.000
3.760.133
1.557.443
1.850.356
546.765
674.093
927,172 196
6,561,310 938
2.162.216 257
5.463.001 461
2.592.421 140
3,356,666 127
949.562 32
1.120.795 15
39.512 176
167,577 775
51.476 163
92.261 271
28,011 61
25.367 33
6.414 4
2.965 2
10,165
15.464
19.474
34,403
68.013
160,888
407.664
1.059,921
Syilem Site OSMCoit Annual Cap Coil No. ofSllei Monitoring Coil No, ofSyi. Coil per
Above Reg. forSyitemi Above Reg. Syiltm
Limit Above Reg. Limit
Limit
WS
VS
S
M
L
6.063.740
5.101.315
1,557,443
2.397.121
674.093
7,488,483 1.135 ) 227.088 9515
7.845,218 719 $ 143.739 453.8
2,592,421 140 $ 28.011 61.4
4.306,227 159 * 31.781 362
1.120.795 IS $ 2,985 1.7
14.482
28,399
68.013
166.012
1,058,921
Household Costs HH Consumption (gal): 83,000
Syitem Size
25-100
101-500
501-1000
1001-3,300
3,301-10,000
10.001-50,000
50.001-100,000
100.001-1.000,000
DIM Coil
826.364
5,237,376
1.341.182
3.760.133
1.657,443
1.650.356
546.765
674.093
Annual Cap
Coil S
927,172
6,561.310
2. 162.216
5.483.001
2,592.421
3,356,666
949.562
1.120.795
Monitoring Coil for Average Daily Row No. ofSyi.
ytlimi Above Reg. (MOD) Above Reg.
Limit Limit
39,512 00071 176
187,577 00348 775
51,476 00947 183
92,261 0.2505 271
28.011 08252 61
25,367 3.2049 33
6,414 11.1710 4
2,985 37.5902 2
HH
ncremenlal
Coil
324.90
101.52
46.76
31.24
1874
11.42
830
641
Syitem Size
WS
VS
S
M
0»M Coil
6.063,740
5,101.315
1.557.443
2.397.121
674,093
Annual Cap Coil
7.488.463
7.645.218
2,592.421
4.306.227
1,120,795
Monitoring Average Dally Affected
Coil lor Flow (MOD) Syitemi
Syitemi
Above Reg.
Llmll
227.086 00285 9515
143,739 0.1878 4539
26,011 06252 SI. 4
31.781 40158 36.2
2,885 37 5902 1 7
HH
Incremental
Coil
11149
34.38
16.74
10.53
641
D1-13
-------
Results (1000 MCL)
PRIVATE
Monitoring Costa
Co»t Frequency
Monitoring Cost $ so 4
System Size No. of Sites No. of
'• Syiloml
25-100 133168 11890
101.500 112578 9304
501-1000 22560 1600
1001.3.300 23052 1356
3,301-10.000 9439 414
10,001-90.000 8463 217
50,001.100,000 2001 23
100,001-1,000,000 114.4 13
Tolil Annul!
Monitoring Coil
2.663.360
2.251.668
451.200
461,040
188,784
169.260
40.020
22,880
Cost per System
224
242
282
340
456
780
1.740
1,760
System Size No. orsit« No. of Total Annual
Systems Monitoring
Cost
WS 24574.6 211940 * 4,914,926
VS 4561.2 29960 I 912.240
S 943.9 4140 ( 188.784
M 10484 240.0 i 209.280
L 1144 130 J 22,880
Colt per System
232
309
456
872
1.760
Totals
System Size
25-100
101-500
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
Total
O1M Cost
8.620.062
10.224.654
721.236
1,138.718
287,767
353.363
95.560
162,084
21,603,644
Annual Cap
Cost
9.019.509
12.304.744
1.163.746
1.667.121
481.154
645,604
167.928
271,206
25,711.010
Annual Cap Cost
95.552,603
130,356.635
12.222.805
17.661,607
5.097,351
6,639.540
1,779.009
2,873,156
272.382.805
Total Annual
Monitoring Cost
2.683,360
2.251.568
451.200
461.040
188,784
169,260
40.020
22.880
6.248.112
Total Annual
Coil
20.302,931
24.781.166
2,326.182
3,266.879
957,705
1,168,227
303,508
456.170
50,562.766
System Size
WS
VS
S
M
L
Total
O&M Cost
18.844,918
1,859.954
287,767
448,923
162.084
21,603.644
Annual Cap
Cost
21.324.253
2,820.868
481,154
813.530
271,206
25.711.010
Cap Cost
225.909,437
29,884.311
5.097.351
8.618.549
2,873.156
272.382.805
Annual
Monitoring
Coal
4.914,928
912.240
188.784
209,280
22.880
'6,248,112
Total
4S.084.097
5,593,061
957.70S
1.471,733
466,170
l.vfSS.SMJW
Par System Cosls
System Siia
25-100
101-500
501.1000
1001-3,300
3,301-10,000
10,001-50,000
50,001.100.000
100,001-1,000,000
Household Costs
System Size
25-100
101-500
501-1000
1001-3,300
3.301-10.000
10,001-50.000
50,001-100,000
100,001.1,000,000
O&M Cost
8.620,082
10,224.854
721,238
1.138,718
287,767
353,363
95,560
162.084
Annual Cap
Cost
9.019.509
12.304.744
1,153.746
1.667,121
481,154
645.604
167.926
271.206
HH Consumption (gal):
DIM Cost
8.620,082
10.224,854
721.236
1,138.716
287,767
353,363
95.560
182.084
Annual Cap
Cost
S 9.019. BOB
$ 12,304,744
1.153.740
1,667,121
481,154
645.604
187,926
271,206
NO. Of Silts Above
Reg. Limit
2.210
2.224
164
187
30
28
7
4
63,000
Monitoring Cost for
Systems Above Reg.
Limit
441,949
444.753
32.711
33.424
6.097
5,521
1.305
746
Monitoring Cost for
Systems Above Reg.
Limit
441,949
444,753
32,711
33,424
6.097
5.521
1.305
746
Average Dally Flow
(MOD)
00052
0.0216
0.0726
0.1922
0.6543
2.7355
9.1202
360777
No. of Sys.
Above Reg.
Limit
1,973
1.838
118
98
13
7
1
0
No. of Sys.
Above Reg.
Limit
1,973
1,838
116
98
13
7
1
0
Cost per
System
9,165
12.501
18.446
28.882
57,964
141,907
352,934
1,023,529
System Size
WS
VS
S
M
L
HH
Incremental
Cost
40277
131.72
5153
3417
20 15
1180
880
845
System Size
WS
VS
S
M
L
04M Cost
18.844.916
1.859.954
287.767
448.923
162,084
O&M Cost
S 18.844.916
$ 1,859.954
J 287,767
S 448,923
5 182.084
Annual Cap Cost
S 21,324,253
$ 2.820.868
5 481.154
S 813.530
( 271.206
Annual Cap Cost
21.324.2S3
2.820,868
481,154
813,530
271.206
No. of Sites
Above Reg.
Limit
4.434
331
30
34
4
Monitoring
Cost lor
Systems
Above Reg.
Limit
S 886,703
$ 66.134
$ 6.097
S 6.827
» 746
Monitoring Cost
for Systems
Above Reg.
Limit
886,703
66,134
0,097
6,827
746
Average Dally
Flow (MOD)
0.0131
01274
06543
33474
36.0777
No. of Sys. Coal per
Above Reg. System
Limit
3.8108 I 10.774
214.3 $ 22,151
13.4 i 57.964
76 $ 162,130
0.4 J 1,023,529
Affected HH
Systems Increments!
Cost
3,6108 » 187.21
2143 t 38.52
13.4 t 20. IS
7.8 1 11.01
0.4 S 845
DM4
-------
Results (2000 MCL)
PUBLIC
Monitoring Cosu
Coil Frequency
Monitoring Cost 1 so 4
Syit«m Sin No. of Sttee No. of
• "• Systems
JJ-100 1190.6 1063
101-SOO 4748.0 3924
501-1000 '3550,4 2518
1001-3,300 6363.1 3743
3,301-10,000 4336.6 1902
10,00140.000 3B88.3 897
50,001-100,000 963.1 113
100,001-1,000,000 4578 52
Tola! Annual
Monitoring Coat
238.112
949.608
710,076
1.272.820
887.312
777.660
196,620
91.520
Coil par System
224
242
282
340
4S8
780
1,740
1,760
System Site No. of Sites No. of
Systems
WS 5938.6 4987
VS 99135 6261
S 4338.6 1902
M 4871.4 1110
l_ 457.8 52
Tola! Annual
Monitoring
Cost
1.167,720
1.982,696
867.312
974,260
91,520
Coat per Sy»l«m
236
317
456
878
1,760
ToUl*
System Site
25-100
101-SOO
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
Tola!
DIM Coal
340.909
2,733.850
413.320
1,158.679
409,208
342.952
100.630
123.953
5.823.401
Annual Cap
Coat
400,872
3,570.384
6*0,727
1.677,795
672,407
619,576
174.759
206,026
7.982.346
Cap Coal
4,244,725
37.624.695
8.999,754
17,774,588
7,123.487
6.563.797
1,851.400
2.182.644
84,565,091
Annual Monitoring
Coal
238.112
949,608
710,076
1,272.820
867.312
777,660
198.620
91.520
5.103,528
Total Annual
Coal
879.893
7.253.542
1.784,124
4,109.295
1.948.927
1.740.188
472.009
$ 421.499
$18,709,278
System Sli«
WS
vs
s
M
L
Tolal
OiM Cost
3.074.459
1,572.200
409.208
443.582
123.953
5,623,401
Annual Cap
Coal
3.971.056
2.338.523
672.407
794,335
206,026
7.982.346
Cap Coat
42.089,421
24.774.342
7.123.487
6.415.198
2.182.644
84.565.091
Annual
Monitoring
Coal
1,187.720
1,882,696
867.312
874.260
81,520
5. 103.528
Tolal
8,233.235
5.693.418
1,948,927
2,212.197
421,499
tP1i;70tt»
Par System Coats
Syatam Size
25-100
101-500
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100.000
100,001-1,000,000
OiM Cost
340.909
2,733.550
413,320
1.158.879
409,208
342.952
100.630
123.953
Annual Cap No. of Silts Above
Cost Reg. Limit
400,672 87
3,570.384 520
660,727 79
1,677,795 141
672,407 37
619,576 23
174,759 6
2O8.028 3
Monitoring Cost for No, of Sys.
Systems Above Above Reg.
Rag. Limit Limit
17.454 78
103,936 429
15,786 56
28,293 83
7,301 16
4.684 8
1,184 1
551 0
Cost par
System
9.741
14.920
19.468
34,429
68.008
181.059
408.341
1.065,278
System Size
WS
VS
S
M
L
OiM Cost
3,074,458
1.572.200
409,208
443.582
123,953
Annual Cap Cost No. of Sites Monitoring Coat No. of Sys.
Above Reg. for Systems Above Reg.
Limit Above Reg. Until
Limit
3.971.056 607 I 121,380 907.4
2,336,523 220 $ 44,078 139.2
672.407 37 I 7.301 16.0
784.335 29 S 5.868 6.7
208.026 3 S 551 0.3
Coat per
System
14.125
28,412
68.008
168,028
1.055.278
HousBhold Costs HH Consumption (gal): 83.000
System Size
25-100
101-500
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
OiM Cost
340,909
2,733,550
413.320
1,156,679
409,208
342.952
100,630
123.953
Annual Cap 1
Cost
t 400.672
3.570,364
660.727
1,677,795
672,407
619,576
174,759
206,026
Monitoring Cost for Average Dally Flow No. of Sys.
Systems Above (MOD) Above Reg.
Reg. Limit Limit
17,454 00071 78
103,836 0.0346 429
15.766 00947 56
28.293 02505 83
7.301 08252 16
4.884 3 2049 6
1.184 11.1710 1 i
551 375902 0 1
HH
ncremental
Cost
311.34
97.94
4875
31.26
16.74
11.43
627
638
System Slie
WS
VS
S
M
L
OiM Cost
3,074,459
1.572.200
409,208
443.582
123.953
Annual Cap Cost
3.971,056
2.338,523
672.407
794.335
206.026
Monitoring Average Dally Affected
Cost for Flow (MOD) Systems
Systems
Above Reg.
Limit
121,390 00304 507.4
44,079 0.1878 138.2
7,301 0.8252 160
5,668 40158 6.7
551 37.5802 0 3
HH
Increments!
Coat
10581
3440
18.74
10.53
6.311
01-1S
-------
Results (2000 MCL)
PRIVATE
Monitoring Coin
Cost Frequency
Monitoring Cost * SO 4
Syilem Silt No. of Silas No. of
Systems
25-100 13318 8 11890
101-500 11257.6 8104
501-1000 22580 1600
10010,300 2305.2 1356
3,901-10,000 9439 414
10,001-50,000 846.3 217
50,001-100,000 200.1 23
100,001-1,000,000 ' 1144 13
Total Annual
Monitoring Cost
2.663.360
2.251,566
451,200
461,040
188784
169,260
40,020
22.BBO
Cast per System
224
242
282
340
456
780
1,740
1.760
System Size No. of Sllet No. of
Systems
WS 24574.6 211940
VS 45612 29560
S 943.9 414.0
M 10464 2400
L 114.4 130
Toll! Annuil Cost per System
Monitoring
Cost
4.914,926 * 232
912.240 $ 309
' 166.784 S 456
209,260 * 872
22,880 $ 1.760
Totals
System Site
25-100
101-500
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
Toll!
O1M Cost
3.574,471
5.339.215
222.110
350.716
75.533
65.466
17.590
29,605
9.674.930
Annuil Cap
Cost
3.899,745
6.662.758
352.147
509.476
124,658
119.152
30.910
49,855
11,768.704
Annul! Clp Cost
41.3t3.S54
70,797.235
3,730.655
5.397.420
1,320,633
1.262.294
327,464
528.167
124,677.822
Tot.l Annu.l
Monitoring Cost
2.883.380
2.251.568
451.200
461.040
188,764
169.260
40,020
22.BBO
6.248.112
Toll! Annuil
Coil
10,137,576
14.273.541
1.025.457
1.321,236
366.976
353.900
88,520
102.S40
F37,«Si;T47!
System Size OHM Cost
WS * 8,913,686
VS $ 572,828
S S 75.533
M i 63.079
L $ 29.805
Total S 9.874.930
Annual Cap
Cost
10.5B2.S03
B6 1.626
124,658
150.062
49.655
11.768.704
Cap Cost
112,111.169
9,128,075
1.320.633
1,589,758
526.167
124,677,622
Annual
Monitoring
Cost
t 4,914.928
912,240
168.784
209,260
22.860
6,248,112
Total
24,411.117
2,346.693
388.976
442.420
102.540
$:?».M1;WK
Per Sy»l»m Co»t»
System Site O*M Cost
25-100 t 3,674.471
101-500 S 5,339.215
501-1000 S 222.110
1001-3,300 t 350.718
3,301-10,000 J 75.533
10,001-50,000 S 65,486
50,001-100,000 ( 17.590
100,001-1,000,000 * 29,605
Annual Cap No. or Sites Above
Coil Reg. Limit
3,899,745 976
6,682,756 1.232
352,147 50
509,476 SI
124,656 6
119.152 S
30,910 1
49.655 1
Monitoring Cost lor No. or Sys.
Systems Above Above Reg.
Reg. Limit Limit
195.232 872
246.437 1,018
10,031 36
10,250 30
1,589 3
1.020 1
241 0
138 0
Cost per
System
8.600
12.048
16.426
26.874
57.897
142,042
351,628
1,019,074
System Size
WS
VS
S
M
L
DIM Cost
8.913.6B6
572.628
75.533
83.079
29,805
Annual Cap Cost No. of Sites H
Above Reg.
Limit
10.582.503 2,206
861.626 101
124,658 6
150,062 6
49,855 1
lonlloring Coat No. of Sys.
lor Systems Above Reg.
Above Reg. Limit
Limit
441,669 1.8899
20.281 65.7
1.589 3.5
1,261 1.4
138 0.1
Coal per
System
10,550
22.136
67.897
162,146
1.019.074
Homehold Costa HH Consumption (gal):
83.000
System Size
25-100
101-500
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
DIM Cost
3.574.471
6,339.215
222.110
350.718
7S.533
66,488
17.590
29,805
Annual Cap
Cost
.
3,899,745
6,682,756
352.147
509,478
124.656
119.152
30.910
49,655
Monitoring Cost for Average Dally Flow No. of Sys.
Systems Above (MOD) Above Reg.
Reg. Limit Limit
195,232 0.0052 672
246.437 00216 1.016
10.031 0.0726 36
10,250 0.1922 30
1,569 0.6543 3
1,020 2.7355 1
241 8.1202 0
138 36.0777 0 1
HH
ncremenlal
Cost
366.73
126.95
51.47
34 16
20.12
11.81
1 8.77
I 6.42
System Size
WS
VS
S
M
L
OtM Cost
8,913,686
572.828
75,533
83,079
29.805
Annual Cap Cost
10,582,503
861.626
124.658
150,062
49.855
Monitoring Average Dally Affected
Coit lor Flow (MGD) Systems
Systems
Above Reg.
Limit
441.669 0.0140 1.668.9
20.281 01274 6S.7
1.589 06543 35
1,261 33474 14
138 360777 0.1
HH
ncremsntal
Cost
171.16
3950
2012
11.02
642
.
DM6
-------
Results (MCL 4000)
PUBLIC
Monitoring Cost*
Co»l Frequency
Monitoring Cost J so «
System Size
25-100
101-500
501-1000
1001-3,300
3,301.10,000
10,001-50,000
50,001-100,000
100,001-1.000,000
Totals
System Size
25-100
101-900
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
Total
No. of Sites No. of
Systems
11906 1063
4748.0 3924
35504 2518
6363.1 3743
43366 1902
3888.3 897
9831 113
457.6 52
O&H Cost Annual Cap
Cost
117.253 148,676
1,019,828 1,730.225
122.044 181.886
342.372 487.912
107,483 176,532
55.509 101,359
16.560 28,759
20,378 33.859
1.801.429 S 2,900.208
Total Annual Cost per System
Monitoring Cost
238,112 224
949,608 242
710,076 262
1,272.620 340
867,312 456
777.660 780
186.620 1,740
81.520 1,760
Cap Cost Annual Monitoring
Cost
1.585.672 S 238,112
16.330.032 * 949,608
2.032,843 710.076
5,168.943 1,272,620
1,870,184 867,312
1.073.803 777.680
304.672 196.820
358.701 91,520
30.724.850 5.103.526
System Size No. of Sites No. of Total Annual Cost per System
Systems Monitoring
Cost
WS 5938.6 4987 1.187,720 238
VS 9913.5 6261 1,982.696 317
S 43366 1902 867.312 456
M 4871.4 1110 974.280 878
L 457.6 52 91.520 1,760
Total Annual
Cost
505.041
3,699,661
1.024.006
2.102.904
1.151,328
934.529
241,939
145.757
8.605,ie5
System Size OSM Cost Annual Cap Cap Cost
Cost
WS 1.137.081 1.879.802 19.815.704
VS 464.417 678,798 7.201.786
S 107,483 176.532 1.670.184
M 72,070 130.118 1,378,475
L 20,378 33,858 358.701
Total 1.801,429 2,900.208 30.724.850
Annual
Monitoring
Cost
1.187.720
1.982.696
867.312
874.280
91.520
5,103.528
Total
4.204,703
3.126,910
1.151,328
1.176,468
145.757
I -Jif:"B,80S.:165'
Par Syttem Costs
System Site
25-100
101-900
501-1000
1001.3,300
3,301.10,000
10,001-50,000
$0.001-100,000
100,001-1,000,000
OJ.M Cost
117.253
1.018.828
122.044
342.372
107.483
55.509
16,560
20.378
Annual Cap No. of Sites Above
Cost Reg. Limit
149,676 33
1.730.225 272
191,886 23
487.912 41
176,532 10
101,359 4
28.759 1
33,859 0
Monitoring Cost for No. of Sys.
Systems Above Reg. Above R«g.
Limit Limit
6.697 30
54.491 225
4.613 16
8.267 24
1,917 4
774 1
196 0
91 0
Cost per
System
9.153
12.455
19,474
34.487
68.008
158.928
404,852
1.050.130
System Size
WS
VS
S
M
L
DIM Cost
1.137.081
464.417
107.483
72.070
20,376
Annual Cap Coal No. of Sites Monitoring Cost No. of Sys.
Above Reg. for Systems Above Reg.
Limit Above Reg. Limit
Limit
1.879.602 306 * 61.188 255.1
679.798 64 I 12.8BO 40.7
176.532 10 t 1.917 42
130.118 5 S 869 1.1
33,859 OS S1 Q.1
Cost per
System
12.068
28.448
68.008
163.664
1,050.130
Household Costs HH Consumption (gal): 83.000
System Sl» O&M Cost Annual Cap Monitoring Cost for Average Daily Flow No. of Sys. HH
Cost Systems Above (MOD) Above Reg. Incremental
Reg. Limit Limit Cost
25-100
101-900
501-1000
1001-3,300
3,301-10,000
10.001-50,000
50,001-100,000
100,001-1,000,000
117,253 S 149,678
1.019,828 S 1.730.225
122.044 I 181.866
342,372 $ 487,912
107,483 S 176.532
55.509 $ 101,359
16.560 S 28.759
20,376 S 33.859
6.697 0.0071 30 S 29254
54.491 0.0346 225 S 8177
4,613 00947 16
8,267 0 2505 24
1.917 0.8252 4
774 32049 1
186 11.1710 0
91 37.5902 0
46.76
3131
1874
1128
824
635
System Size
DIM Cost
Annual Cap Cost Monitoring Average Dally Affected
HH
Cost for Flow(MGO) System* Incremental
WS
VS
S
M
L
1,137.081
464,417
107,483
72.070
20.378
Systems
Above Reg.
Limit
1,878.802 S 61,188 0.0314 255.1
678,788 t 12,880 0.1878 407
176,532 * 1.917 0.8252 4.2
130.118 S 989 ' 4.0158 1.1
33.859 » 91 37.5902 0.1
Cost
87.30
34.45
18.74
10.42
. 635
01-17
-------
Results (MCL 4000)
Privito
Monitoring Coats
Coit Frequency
Monitoring Cost J so 4
System Size No. of Sites No. of
Systems
25-100 13318.6 11890
101-500 11257.8 9304
501-1000 22560 1600
1001-3,300 2309.2 1356
3,301-10.000 B43.B 414
10,001-50,000 848.3 217
90,001-100,000 200.1 23
100,001-1,000,000 114.4 13
Total Annual
Monitoring Coil
2,663,380
2.251,563
451,200
4S1.040
188.784
189.280
40.020
i 22.680
Coil par Syitem
224
242
282
340
458
780
1,740
1.760
System Size No. of Sites No. of
System!
WS 24S746 211940
VS 4561.2 29660
S 943.9 4140
M 1046.4 2400
L 1144 13.0
ToUl Annual
Monitoring
Cost
4.9 14 .928
912.240
168.784
209,280
22,880
Cost per System
232
309
456
672
1,760
Totals
System Size
25-100
101-500
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50.001-100,000
100,001-1,000,000
Totll
OlM Cost
1,240.495
1.998,358
65.485
103,482
19,839
10,605
2.895
4,900
3.446,037
Annual Cip
Cost
1.457.658
3.205,714
102.004
147,731
32.726
19.508
5.088
8.194
4.978.621
Annuil Cap Cost
15.442.450
33,961.375
1.080.636
1,665.069
348,702
206,648
53.698
88,604
52,743.582
Total Annual
Monitoring Cost
i 2,663.360
2,251.568
451.200
461.040
188.784
169,260
40.020
22,880
6.248.112
Total Annual
Cost
5.361.513
7.455.838
618.689
712.233
241,349
199.372
48.003
35.974
U.m.TTQ
Systam Size OlM Coil
WS 5 3,238.851
VS $ 166.946
S $ 19,839
M t 13,501
L S 4,900
Total S 3,446,037
Annual Cap Cap Cost Annual
Cost Monitoring
Cost
4.663.372 S 49.403.825 t 4.914,928
249,736 t 2,645,705 S 912.240
32.726 J 346.702 ( 188,784
24,594 t 260,546 S 209.260
8.194 i 86,804 S 22,680
4,978,621 $ 52.743.582 J 6.248.112
Total
,
$ 12.617,151
t 1.330.922
$ 241,349
t 247,374
$ 35,974
-'tHIHMW
Per System Costa
Systam Slza
M-100
101-500
501-1000
1001-3,300
3,301-10,000
10,001-50,000
50,001-100,000
100,001-1,000,000
OiM Cost
1,240.495
1,998.358
85,485
103,482
19,839
10.805
2,895
4.900
Annual Cap No. of Sites Abova
Cost Reg. Limit
1.457,658 375
3.205,714 646
102,004 15
147,731 15
32,726 2
19.506 1
5,088 0
8,194 0
Monitoring Coil for No. ol Sys.
Systems Above Reg. Above Reg.
Limit Limit
74.904 334
129,202 534
2.931 10
2.995 9
417 1
168 0
40 0
23 0
Cost per
System
6.293
9.989
18.396
28.857
57,895
140,255
350.802
1,014.135
System Size
WS
VS
S
M
L
OIM Cos!
3.238.851
168.946
19.839
13,501
4.900
Annual Cap Cost No. of Sites t
Above Reg.
Limit
4.883,372 1.021
249.736 30
32,726 2
24.594 1
8.194 0
lonltoring Coil No. of Sys.
lor Systems Above Reg.
Above Reg. Limit
Limit
204.108 8883
6.926 192
417 09
208 0.2
23 00
Coil per
System
«.3M
22,112
67.885
180.413
1.014,135
Household Costs HH Consumption (gal):
83,000
System Size
25-100
101-500
501-1000
1001-3,300
3,301-10,000
10.001-50,000
50,001-100,000
100,001-1,000,000
O&M Cost
1,240,495
1,998.356
85,485
103.462
19,839
10,605
2,895
4.900
Annual Cap
Cost
1,457,658
3,205,714
102.004
147.731
32.726
19.508
5,088
8.194
Monitoring Cost tor Average Dally Flow No. of Sys.
Systems Above (MOD) Above Reg.
Reg. Limit Limit
74.904 0.0052 334
129,202 0.0218 534
2.931 00726 10
2,995 01922 9
417 0.6543 1
168 2.7355 0
40 91202 0
23 360777 0
HH
ncremenlal
Cost
364.48
10526
51 37
34.14
2012
1166
874
639
Syslem Size
WS
VS
S
M
L
OIM Cost
3.238.851
168.946
19.839
13.501
4,900
Annual Cap Cos!
4,883,372
249.738
32,726
24.594
8,194
Monitoring Average Dally Affected
Cost for Flow (MOD) System*
Systems
Above Reg.
Limit
204.108 0.0153 6683
5.926 0.1274 19.2
417 06543 09
208 33474 0.2
23 38.0777 00
HH
incremental
Coit
13910
3945
20.12
10.80
6.39
DM8
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