Economic Analysis 

for the 

Final Revised Total Coliform Rule 
Office of Water (4606M) 

EPA 815-R-12-004 

www.epa.gov/safewater

September 2012 
Economic Analysis for the Final RTCR i September 2012 

Contents

Appendices .................................................................................................................................... vi

Exhibits ........................................................................................................................................ vii

List of Acronyms ........................................................................................................................ xiii

Health Risk Reduction and Cost Analysis ............................................................................... xvi

Executive Summary ................................................................................................................ ES-1

ES.1 Need for the Rule .................................................................................................. ES-1

ES.2 Consideration of Regulatory Options .................................................................... ES-4

ES.3 Summary of the RTCR Requirements ................................................................... ES-5

ES.4 Systems Subject to the RTCR ............................................................................... ES-8

ES.5 National Benefits and Costs of the RTCR ............................................................. ES-8

ES.5.1 Derivation of Benefits ......................................................................................... ES-10

ES.5.2 Derivation of Costs ............................................................................................. ES-19

ES.6 Projected Impacts on Household Costs ............................................................... ES-20

ES.7 Comparison of Benefits and Costs, and Regulatory Options of the RTCR ........ ES-22

ES.8 Conclusion ........................................................................................................... ES-27

1 Introduction ............................................................................................................ 1-1

1.1 Summary of the Revised Total Coliform Rule (RTCR)........................................... 1-1

1.2 Document Organization ........................................................................................... 1-4

1.3 Calculations and Citations ........................................................................................ 1-5

2 Statement of Need for the Rule ............................................................................. 2-1

2.1 Introduction .............................................................................................................. 2-1

2.1.1 Description of the Issue ............................................................................................ 2-1

2.2 Public Health Concerns, Fecal Contamination, and Waterborne Pathogens ........... 2-3

2.2.1 Rule Objectives and Public Health Concerns ........................................................... 2-3

2.2.2 Total Coliforms as Indicators of Treatment Effectiveness and Integrity of the 

Distribution System .................................................................................................. 2-9

2.2.3 Sanitary Defects ....................................................................................................... 2-9

2.2.4 Occurrence of Fecal Contamination and/or Waterborne Pathogens ........................ 2-9

2.3 Statutory Authority for Promulgating the Rule ...................................................... 2-11

2.4 Economic Rationale ............................................................................................... 2-11

3 Consideration of Regulatory Options ................................................................... 3-1

3.1 Introduction .............................................................................................................. 3-1

3.2 Total Coliform Rule/Distribution System Advisory Committee ............................. 3-1

3.3 Regulatory Options Considered ............................................................................... 3-2

3.3.1 Comparative Summary of Regulatory Options ........................................................ 3-5

3.4 Final Rule Requirements ........................................................................................ 3-13
Economic Analysis for the Final RTCR ii September 2012 

4

4.1

Baseline Conditions ................................................................................................ 4-1

Introduction .............................................................................................................. 4-1

4.1.1 Background and Purpose .......................................................................................... 4-1

4.1.2 Chapter Organization ............................................................................................... 4-1

4.2 Data Sources ............................................................................................................. 4-2

4.2.1 Background on SDWIS/FED Data ........................................................................... 4-2

4.2.2 Background on 2005 Six-Year Review 2 Data ........................................................ 4-6

4.2.3 Background on Other Data and Information Used ................................................... 4-9

4.3 Baseline Profile ...................................................................................................... 4-11

4.3.1 Pre-GWR Baseline ................................................................................................. 4-12

4.3.2 Post-GWR Baseline ................................................................................................ 4-15

4.3.3 Baseline Population Served .................................................................................... 4-17

4.3.4 Baseline Water Quality .......................................................................................... 4-19

4.4 Sensitive Sub-Populations ...................................................................................... 4-24

4.5 Summary of Baseline Assumptions ....................................................................... 4-25

5 Occurrence and Predictive Model ........................................................................ 5-1

5.1 Introduction .............................................................................................................. 5-1

5.2 Modeling of Current Total Coliform and E. coli Occurrence for Systems 

Serving ≤4,100 People ............................................................................................. 5-3

5.2.1 Distributional Model and Notation ........................................................................... 5-3

5.2.2 Data Reduction ......................................................................................................... 5-3

5.2.3 Basic Subsets of Systems ......................................................................................... 5-4

5.2.4 Estimation Methodology .......................................................................................... 5-6

5.2.5 Results ...................................................................................................................... 5-9

5.3 Predictive Modeling of Occurrence for Systems Serving Up to 4,100 People ...... 5-15

5.3.1 Summary of GWR factors and timing affecting the 1989 TCR and RTCR ........... 5-15

5.3.2 Summary of Predictive Model ............................................................................... 5-18

5.3.3 Predictive Model Results ........................................................................................ 5-27

5.4 Occurrence Analysis for Systems Serving More Than 4,100 People .................... 5-54

5.4.1 Model (for Systems Serving >4,100 People) ......................................................... 5-55

5.4.2 Model Results (for Systems Serving >4,100 People)............................................. 5-56

5.4.3 Model Uncertainty (for Systems Serving >4,100 People) ..................................... 5-56

5.5 Summary of Key Drivers for Benefit and Cost Analyses Output from the 

Predictive Model .................................................................................................... 5-59

6 Benefits Analysis ..................................................................................................... 6-1

6.1 Introduction .............................................................................................................. 6-1

6.2 Qualitative Benefits Analyses .................................................................................. 6-1

6.2.1 Implementation Activities ........................................................................................ 6-2
Economic Analysis for the Final RTCR iii September 2012 

6.2.2 Routine Monitoring .................................................................................................. 6-2

6.2.3 Repeat Monitoring .................................................................................................... 6-5

6.2.4 Additional Routine Monitoring ................................................................................ 6-6

6.2.5 Annual Site Inspections ............................................................................................ 6-7

6.2.6 Assessments .............................................................................................................. 6-8

6.2.7 Corrective Actions .................................................................................................... 6-9

6.2.8 Public Notification ................................................................................................... 6-9

6.2.9 Summary of Qualitative Benefits Analyses ........................................................... 6-16

6.3 Assessment of Predictive Analysis Results ............................................................ 6-16

6.3.1 Assessment of Predictive Analysis Results for Systems Serving ≤4,100 People 

and Systems Serving >4,100 People ...................................................................... 6-18

6.4 Uncertainty and Sensitivity Analyses ..................................................................... 6-28

6.5 Other Potential Benefits ......................................................................................... 6-32

6.5.1 Increased System Knowledge ................................................................................ 6-32

6.5.2 Accelerated Infrastructure Repair/Replacement .................................................... 6-32

6.5.3 Reduction in Averting Behavior ............................................................................. 6-33

6.5.4 Reduction of Co-Occurring and Other Contaminants ............................................ 6-33

6.5.5 Reduction in Outbreak Risk and Response Costs .................................................. 6-33

7 Cost Analysis ........................................................................................................... 7-1

7.1 Introduction .............................................................................................................. 7-1

7.2 General Cost Assumptions and Methodology .......................................................... 7-1

7.2.1 Labor Rates ............................................................................................................... 7-2

7.2.2 TCR Monitoring Costs per Sample .......................................................................... 7-3

7.2.3 Technology Unit Costs and Compliance Forecasts .................................................. 7-3

7.2.4 Cost Model ............................................................................................................... 7-4

7.2.5 Modeled Variability and Uncertainty in National Costs .......................................... 7-4

7.3 Projecting and Discounting National Costs .............................................................. 7-5

7.4 Derivation of Costs for PWSs and States ................................................................. 7-6

7.4.1 Rule Implementation and Annual Administration ................................................... 7-6

7.4.2 Revise Sample Siting Plan ....................................................................................... 7-9

7.4.3 Monitoring .............................................................................................................. 7-12

7.4.4 Annual Site Visits ................................................................................................... 7-19

7.4.5 Assessments ............................................................................................................ 7-19

7.4.6 Corrective Actions .................................................................................................. 7-28

7.4.7 Public Notification ................................................................................................. 7-33

7.4.8 Uncertainty in Unit Costs ....................................................................................... 7-38

7.5 Household Costs ..................................................................................................... 7-38

7.6 Non-quantified Costs .............................................................................................. 7-41
Economic Analysis for the Final RTCR iv September 2012 

7.7 Uncertainty Analysis .............................................................................................. 7-41

7.8 Comparison of Total and Net Annualized Costs for All Regulatory Options ........ 7-45

8 Economic Impact Analysis .................................................................................... 8-1

8.1 Introduction .............................................................................................................. 8-1

8.2 Executive Order 12866: Regulatory Planning and Review ...................................... 8-2

8.3 Paperwork Reduction Act ........................................................................................ 8-2

8.4 The Regulatory Flexibility Act ................................................................................. 8-6

8.5 Unfunded Mandates Reform Act ........................................................................... 8-10

8.6 Executive Order 13132: Federalism ....................................................................... 8-11

8.7 Executive Order 13175: Consultation and Coordination with Indian Tribal 

Governments .......................................................................................................... 8-12

8.8 Executive Order 13045: Protection of Children from Environmental Health 

Risks and Safety Risks ........................................................................................... 8-13

8.9 Executive Order 13211: Action Concerning Regulations That Significantly 

Affect Energy Supply, Distribution, or Use ........................................................... 8-13

8.10 National Technology Transfer and Advancement Act ........................................... 8-14

8.11 Executive Order 12898: Federal Actions to Address Environmental Justice in 

Minority Populations and Low-Income Populations .............................................. 8-15

8.12 Consultations with the Science Advisory Board, National Drinking Water 

Advisory Council, and the Secretary of Health and Human Services as 

Required by Section 1412 (d) and (e) of the SDWA ............................................. 8-15

8.13 Consideration of Impacts on Sensitive Subpopulations as Required by Section 

1412(b)(3)(c)(i)(V) of the 1996 Amendments to the Safe Drinking Water Act 

(SDWA) .................................................................................................................. 8-16

8.14 Effect of Compliance with the RTCR on the Technical, Financial, and 

Managerial Capacity of Public Water Systems as Required by Section 

1420(d)(3) of SDWA .............................................................................................. 8-17

8.14.1 Requirements of the RTCR .................................................................................... 8-18

8.14.2 Systems Subject to the RTCR ................................................................................ 8-18

8.14.3 Impact of the RTCR on System Capacity .............................................................. 8-19

8.14.4 Derivation of RTCR Scores ................................................................................... 8-21

8.14.5 Small Water Systems (Those Serving 10,000 or Fewer People) ........................... 8-22

8.14.6 Large Water Systems (Those Serving Greater Than 10,000 People) ..................... 8-23

9 Comparison of Benefits and Costs ........................................................................ 9-1

9.1 National Benefits and Costs of the RTCR Considered in Comparison to the 

1989 Total Coliform Rule and Alternative Option .................................................. 9-1

9.1.1 National Benefits of the Regulatory Options Considered ........................................ 9-3

9.1.2 National Cost Summary ......................................................................................... 9-18

9.1.3 Comparison of National Benefits and Costs of the Regulatory Options 

Considered .............................................................................................................. 9-26
Economic Analysis for the Final RTCR v September 2012 

9.2 Effect of Uncertainties and Non-quantified Benefit/Cost Estimates on the 

Estimation of National Benefits and Costs ............................................................. 9-27

9.2.1 Summary of Major Uncertainties in EA Analyses ................................................. 9-27

9.2.2 Summary of Non-quantified Costs and Benefits .................................................... 9-29

9.3 Comparison of the Regulatory Options Considered ............................................... 9-30

9.3.1 Net Change in Costs and Benefits .......................................................................... 9-30

9.3.2 Cost Effectiveness Measures .................................................................................. 9-31

9.3.3 Break-Even Analysis .............................................................................................. 9-33

9.3.4 Summary of Conclusions ....................................................................................... 9-39

10 References ............................................................................................................. 10-1

 
Economic Analysis for the Final RTCR vi September 2012 

Appendices 

Appendix A: Detailed Predictive Model Results 

Appendix B: Graphs of Predicted Occurrence Over Time 

Appendix C: Detailed Cost Model Results 

Appendix D: Detailed Compliance Forecast and Unit Costs Estimates 

Appendix E: Break-Even Analysis 

Appendix F: Alternative Strategies for Combining Basic Subsets 

Appendix G: Evaluation of Representativeness of Six-Year Review 2 Data

Appendix H: Analysis of Repeat Sample Records from the Six-Year Review 2 Data 

Appendix I: Supporting Information for Regulatory Flexibility Act Screening Analysis 
Economic Analysis for the Final RTCR vii September 2012 

Exhibits 

Executive Summary 

Exhibit ES.1 Implementation Schedule ...................................................................................ES-8 

Exhibit ES.2 Modeled TC+ Occurrence in Transient Noncommunity Ground Water 

 Systems Serving ≤ 4,100 ..................................................................................ES-12

Exhibit ES.3 Potential Changes in Risk under the RTCR and Alternative Option 

 Relative to the 1989 TCR ................................................................................ES-13 

Exhibit ES.4 Predicted Annual Number of Acute (1989 TCR) or E. coli MCL (RTCR and 

Alternative Option) Violations by Regulatory Option and 

 System Type (Year 9) ......................................................................................ES-18 

Exhibit ES.5 Comparison of Total and Net Change from 1989 TCR in Annualized 

 Present Value Costs ($Millions, 2007$) ..........................................................ES-20 

Exhibit ES.6 Summary of Net Annual Per-Household Costs for the RTCR (2007$)...........ES-22 

Exhibit ES.7 Estimated Annual Breakeven Threshold for Avoided Cases of 

 STEC O157....... ...............................................................................................ES-24 

Exhibit ES.8 Estimated Annual Breakeven Threshold for Avoided Cases of 

 Salmonella........................................................................................................ES-25 

Exhibit ES.9 Total Net Annual Cost Per Corrective Action Implemented under 

 the RTCR and Alternative Option, Annualized Using 3% and 7% 

 Discount Rates ($2007)....................................................................................ES-26 

Exhibit ES.10 Annualized Net Change in Costs Per Corrective Action (CA) 

 Implemented for All PWSs under the RTCR and Alternative Option 

 ($Millions, 2007$) ...........................................................................................ES-27 

Exhibit ES.11 Annualized Net Change in Costs Per CA Implemented for TNCWSs 

 (Serving <100 people) under the RTCR and Alternative Option 

 ($Millions, 2007$) ...........................................................................................ES-27 

1. Introduction 

Exhibit 1.1 RTCR Monitoring Frequency Requirements ....................................................... 1-3 

2. Statement of Need for the Rule 

3. Consideration of Regulatory Options 

Exhibit 3.1 Comparison of RTCR Regulatory Options .......................................................... 3-6 

4. Baseline Conditions 

Exhibit 4.1 Pre-GWR Baseline Number of GW Systems .................................................... 4-13

Exhibit 4.2 Baseline Number of SW Systems ...................................................................... 4-13

Exhibit 4.3 Pre-GWR Baseline Population Served by GW Systems ................................... 4-14

Exhibit 4.4 Percent Distribution of GW System Monitoring Frequencies by 

 PWS Size and Type for 1989 TCR .................................................................... 4-15
Economic Analysis for the Final RTCR viii September 2012 

Exhibit 4.5 Baseline Number of GW Systems Post-Implementation of the 

 GWR (Model Year 5) ....................................................................................... 4-17 

Exhibit 4.6 Baseline Population Served by GW Systems Post-Implementation 

 of the GWR (Model Year 5) .............................................................................. 4-18 

Exhibit 4.7 Baseline Population Served by SW Systems ..................................................... 4-18 

Exhibit 4.8 Household Baseline ........................................................................................... 4-19 

Exhibit 4.9 Total Coliform and E. coli Percent Positive by System Size and Type ............. 4-21

Exhibit 4.10 Baseline Number of 1989 TCR Violations by System Size and 

 Type (2005)....... ................................................................................................. 4-23

Exhibit 4.11 Number of PWSs with Violations by System Type (2001–2007) ..................... 4-24 

Exhibit 4.12 Estimates of Sensitive Subpopulations in the United States .............................. 4-25 

Exhibit 4.13 Summary of Baseline Assumptions Influencing RTCR Estimates.................... 4-26 

5. Occurrence and Predictive Model 

Exhibit 5.1 Basic Classifications of PWSs Used for Occurrence Modeling .......................... 5-5 

Exhibit 5.2 Directed Graph of Model Used for RTTC Occurrence ....................................... 5-7 

Exhibit 5.3 Maximum Likelihood a and b Parameter Estimates for RTTC and RPTC ....... 5-10 

Exhibit 5.4 Maximum Likelihood a and b Parameter Estimates for RTEC and RPEC ....... 5-11 

Exhibit 5.5 α and β Parameter Estimates for RTTC and RPTC .......................................... 5-13 

Exhibit 5.6 α and β Parameter Estimates for RTEC and RPEC .......................................... 5-14 

Exhibit 5.7 Simulated Impact of the RTCR and Alternative Option on Systems 

 Serving ≤4,100 People—Surface Water Systems .............................................. 5-22 

Exhibit 5.8 Simulated Impact of the RTCR and Alternative Option on Systems 

 Serving ≤4,100 People—Ground Water Systems .............................................. 5-23 

Exhibit 5.9a Percent of GW Systems Assumed to be on Monthly, Quarterly, and 

 Annual (M/Q/A) Monitoring by System Category under 1989 

 TCR (Baseline)—Initial Estimates (Post-GWR Implementation) ..................... 5-24 

Exhibit 5.9b Percent of GW Systems Predicted to be on M/Q/A Monitoring by 

 System Category under RTCR—Adjusted Estimates 

 (Post-RTCR Implementation) ............................................................................ 5-25 

Exhibit 5.9c Percent of GW Systems on M/Q/A Monitoring by System 

 Category under Alternative Option—Adjusted Estimates 

 (Post-RTCR Implementation) ............................................................................ 5-26 

Exhibit 5.10 Ground Water Community Water System Model Output Cumulative 

 Endpoints...... ................................................................................................... 5-30 

Exhibit 5.11 Ground Water Nontransient Noncommunity Water System Model Output 

Cumulative Endpoints ........................................................................................ 5-30 

Exhibit 5.12 Ground Water Transient Noncommunity Water System Model Output 

 Cumulative Endpoints ........................................................................................ 5-31 

Exhibit 5.13 Surface Water Community Water System Model Output Cumulative 

 Endpoints...... ................................................................................................... 5-31 

Exhibit 5.14 Surface Water Nontransient Noncommunity Water System Model Output 

Cumulative Endpoints ........................................................................................ 5-32 

Exhibit 5.15 Surface Water Transient Noncommunity Water System Model Output 

 Cumulative Endpoints ........................................................................................ 5-32 
Economic Analysis for the Final RTCR ix September 2012 

Exhibit 5.16 Ground Water Community Water System (Serving ≤ 4,100) 

 TC Occurrence ................................................................................................... 5-33

Exhibit 5.17 Ground Water Nontransient Noncommunity Water System 

 (Serving ≤ 4,100) TC Occurrence ...................................................................... 5-34 

Exhibit 5.18 Ground Water Transient Noncommunity Water System 

 (Serving ≤ 4,100) TC Occurrence ...................................................................... 5-35 

Exhibit 5.19 Surface Water Community Water System (Serving ≤ 4,100) 

 TC Occurrence ................................................................................................... 5-36

Exhibit 5.20 Surface Water Nontransient Noncommunity Water System 

 (Serving ≤ 4,100) TC Occurrence ...................................................................... 5-37 

Exhibit 5.21 Surface Water Transient Noncommunity Water System 

 (Serving ≤ 4,100) TC Occurrence ...................................................................... 5-38 

Exhibit 5.22a Summary of Model Parameters Influencing 1989 TCR, RTCR and 

 Alternative Option ............................................................................................. 5-40 

Exhibit 5.22b Summary of Model Parameters Influencing RTCR and 

 Alternative Option Only .................................................................................... 5-43 

Exhibit 5.23 Sensitivity Analysis Assumptions for Frequency and Effectiveness of 

 Corrective Actions following Level 1 or 2 Assessments ................................... 5-48 

Exhibit 5.24a Cumulative Effect of Alternative Assumptions for Corrective Action 

 (CA) Effectiveness and Duration on RTCR Model Results 

 (Nondisinfecting TNCWS Serving ≤500 People over 25 Years) ...................... 5-48 

Exhibit 5.24b Cumulative Effect of 50 percent Assumption for Corrective Action 

 Implementation Rate on RTCR Model Results (Nondisinfecting 

 TNCWS Serving ≤500 People over 25 Years) .................................................. 5-50 

Exhibit 5.25 Effect of Seasonality on Occurrence Analysis Endpoints ................................. 5-51 

Exhibit 5.26 Comparison of TC+ Occurrence Predicted as a 25-Year Annual 

 Average under the 1989 TCR with 2005 Six-Year Review Data ...................... 5-53 

Exhibit 5.27 Comparison of SDWIS Data for Non-acute and Acute Violations with 

 Predictive Model Annual Results for the 1989 TCR ......................................... 5-54 

Exhibit 5.28 Results for Systems Serving more than 4,100 People—1989 TCR................... 5-57 

Exhibit 5.29 Results for Systems Serving more than 4,100 People—RTCR ......................... 5-58 

Exhibit 5.30 Results for Systems Serving more than 4,100 People—Alternative Option ..... 5-59 

6. Benefits Analysis 

Exhibit 6.1 Potential Changes in Risk under the RCTR and Alternative Option 

 Relative to the 1989 TCR .................................................................................. 6-13 

Exhibit 6.2 Predicted Outcomes (25-Year Period of Analysis) under the 1989 TCR .......... 6-22 

Exhibit 6.3 Predicted Outcomes (25-Year Period of Analysis) for the RTCR ..................... 6-23 

Exhibit 6.4 Predicted Outcomes (25-Year Analysis Period) for the Alternative Option ..... 6-24 

Exhibit 6.5 Predicted Average Annual Acute Violations by Regulatory 

 Option and System Type .................................................................................... 6-25 

Exhibit 6.6 Predicted Change in Average Annual Acute Violations by 

 Regulatory Option and System Type ................................................................. 6-26 

Exhibit 6.7 Relative Impacts Analysis for TNCWS Serving <101 People 

 for the Range of Corrective Action and Sampling Regimens Predicted ........... 6-30 
Economic Analysis for the Final RTCR x September 2012 

7. Cost Analysis 

Exhibit 7.1 Labor Rates by PWS Size (2007$) ...................................................................... 7-2 

Exhibit 7.2 Monitoring Costs per Sample (2007$) ................................................................. 7-3 

Exhibit 7.3 Net Change in PWS Unit Burden and Cost Estimates for Rule 

 Implementation (2007$)....................................................................................... 7-7 

Exhibit 7.4 Net Change in State Unit Burden and Cost Estimates for Rule 

 Implementation (2007$)....................................................................................... 7-8 

Exhibit 7.5 Annualized Cost Estimates for Rule Implementation 

 ($Millions, 2007$) ............................................................................................... 7-9 

Exhibit 7.6 Net Change in PWS and State Burden and Cost Estimates to 

 Revise Sample Siting Plans (2007$) .................................................................. 7-11 

Exhibit 7.7 Annualized Cost Estimates to Revise (PWSs) and Review (States) 

 Sample Siting Plans ($Millions, 2007$) ............................................................ 7-12 

Exhibit 7.8 Summary of Monitoring Requirements Under the 1989 TCR, RTCR, 

 and Alternative Option ....................................................................................... 7-13 

Exhibit 7.9 Cumulative Number of Samples over 25-Year Period of Analysis ................... 7-17 

Exhibit 7.10 Annualized PWS and State Cost Estimates for Monitoring Costs 

 ($Millions, 2007$) ............................................................................................. 7-18 

Exhibit 7.11 PWS Unit Costs Estimates for Assessment Activities 

 (1989 TCR) (2007$) .......................................................................................... 7-22 

Exhibit 7.12 PWS Unit Costs Estimates for Level 1 and Level 2 Assessments 

 (RTCR and Alternative Option) (2007$) ........................................................... 7-23 

Exhibit 7.13 Number of Level 1 and Level 2 Assessments over the 25-Year 

 Compliance Period ............................................................................................. 7-24 

Exhibit 7.14 State Unit Cost Estimates for Review of Level 1 and Level 2 

 Assessments under the 1989 TCR, RTCR, and Alternative 

 Option (2007$) ................................................................................................... 7-27

Exhibit 7.15 Annualized PWS and State Cost Estimates for Level 1 and Level 2 

 Assessments ($Millions, 2007$) ........................................................................ 7-28

Exhibit 7.16a Compliance Forecast for Corrective Actions based on Level 1 and 

 Level 2 Assessments .......................................................................................... 7-30

Exhibit 7.16b Detailed PWS Compliance Forecast for Corrective Actions based on 

 Level 1 and Level 2 Assessments ...................................................................... 7-31

Exhibit 7.17 Net Change in PWS and State Unit Costs Estimates for Reporting and 

Recordkeeping for Corrective Actions (2007$) ................................................. 7-32

Exhibit 7.18 Annualized PWS and State Cost Estimates for Corrective Actions 

 based on Level 1 and Level 2 Assessments ($Millions, 2007$) ........................ 7-33

Exhibit 7.19 PWS Unit Cost Estimates for Public Notification (2007$) ............................... 7-35

Exhibit 7.20 State Unit Costs Estimates for Public Notification (1989 TCR, RTCR, 

 Alternative Option) ............................................................................................ 7-36

Exhibit 7.21 Number of Tier 1 and Tier 2 Public Notifications over the 25-Year 

 Compliance Period ............................................................................................. 7-37

Exhibit 7.22 Annualized PWS and State Cost Estimates for Public Notification 

 ($Millions, 2007$) ............................................................................................. 7-38
Economic Analysis for the Final RTCR xi September 2012 

Exhibit 7.23 Summary of Net Annual Per-Household Costs for the RTCR (2007$)............. 7-40

Exhibit 7.24 Sensitivity Analysis—Annualized Net Change in Costs based on 

 Changes in Compliance Forecast ($Millions, 2007$) ........................................ 7-43

Exhibit 7.25 Cost Uncertainty Summary ................................................................................ 7-44

Exhibit 7.26 Comparison of Total and Net Change from 1989 TCR in 

 Annualized Present Value Costs ($Millions, 2007$) ......................................... 7-45

Exhibit 7.27 Comparison of Total and Net Change in Annualized Present 

 Value Costs by Rule Component ($Millions, 2007$) ........................................ 7-46

Exhibit 7.28 Total and Net Change in Annualized Costs to PWSs by 

 PWS Size and Type ($Millions, 2007$) ............................................................ 7-47

Exhibit 7.29 Total and Net Change in Annualized Per PWS Costs by 

 PWS Size and Type (2007$) .............................................................................. 7-48

8. Economic Impact Analysis 

Exhibit 8.1 Average Annual Net Change Burden and Costs for the RTCR 

 Information Collection Request ........................................................................... 8-5

Exhibit 8.2 RTCR—Average Annualized Revenue by System Size and Percent of 

 Systems with Costs Exceeding One Percent and Three Percent of 

 Revenue (Three Percent Discount Rate) .............................................................. 8-7

Exhibit 8.3 RTCR—Average Costs per System and as Percentage of Revenue 

 (2007$)......... ..................................................................................................... 8-8 

Exhibit 8.4 RTCR—Annualized Net Rule Costs Predicted for Small Entities 

 (PWSs serving ≤10,000) by Rule Component Using Three 

 Percent and Seven Percent Discount Rates (2007$) ............................................ 8-9

Exhibit 8.5 Estimated Impact of the RTCR on Small Systems’ Technical, 

 Managerial, and Financial Capacity .................................................................. 8-20

Exhibit 8.6 Estimated Impact of the RTCR on Large Systems’ Technical, 

 Managerial, and Financial Capacity .................................................................. 8-21

9. Comparison of Benefits and Costs 

Exhibit 9.1a Ground Water (GW) Transient Noncommunity Water Systems 

 (Serving ≤ 4,100) TC Occurrence ........................................................................ 9-5 

Exhibit 9.1b Potential Changes in Risk under the RTCR and Alternative Option 

 Relative to the 1989 TCR .................................................................................... 9-7 

Exhibit 9.2 Estimates of Non-Acute Violations (TCR) and Level 1 Assessment 

 Triggers (RTCR and Alternative Option) .......................................................... 9-13 

Exhibit 9.3 Estimates of Acute Violations (TCR) and E. coli MCL Violations 

 (RTCR and Alternative Option)......................................................................... 9-14

Exhibit 9.4 Estimates of Corrective Actions ........................................................................ 9-15

Exhibit 9.5 Discounted Estimates of Non-Acute Violations (TCR) and Level 1 

 Assessment Triggers (RTCR and Alternative Option) (3% Discount Rate) ..... 9-16

Exhibit 9.6 Discounted Estimates of Acute Violations (TCR) and E. coli

 MCL Violations (RTCR and Alternative Option) (3% Discount Rate) ............ 9-17 

Exhibit 9.7 Discounted Estimates of Corrective Actions (3% Discount Rate) .................... 9-18 
Economic Analysis for the Final RTCR xii September 2012 

Exhibit 9.8 Net Costs to PWSs (2007$) ............................................................................... 9-21 

Exhibit 9.9 Discounted Net Costs to PWSs Over Time (3% Discount Rate) (2007$) ......... 9-22 

Exhibit 9.10 Discounted Net Costs to PWSs (7% Discount Rate) (2007$) ........................... 9-23 

Exhibit 9.11 Comparison of Total and Net Change in Annualized Present 

 Value Costs ($Millions, 2007$) ......................................................................... 9-24 

Exhibit 9.12 Comparison of Total and Net Change in Annualized Present Value 

 Costs by Rule Component ($Millions, 2007$) .................................................. 9-25 

Exhibit 9.13 Total and Net Change in Annualized Costs to PWSs by PWS Size 

 and Type ($Millions, 2007$) ............................................................................. 9-26 

Exhibit 9.14 Net Change in Annualized Present Value Costs ($Millions, 2007$) 

 and Benefits (Number of Level 2 Corrective Actions) ...................................... 9-31

Exhibit 9.15 Total Net Annual Cost per Corrective Action Implemented under 

 RTCR and Alternative Option, Annualized Using 3% and 7% 

 Discount Rates ($2007)...................................................................................... 9-32

Exhibit 9.16 Incremental Rule Cost per Corrective Action (CA) Implemented for 

 All PWSs under RTCR and Alternative Option ($Millions, 2007$) ................. 9-33

Exhibit 9.17 Incremental Rule Cost per CA Implemented for GW TNCWSs 

 (Serving <100 people) under RTCR and Alternative Option 

 ($Millions, 2007$) ............................................................................................. 9-33

Exhibit 9.18 Average Estimated Value per STEC O157 Case Avoided (2007$) .................. 9-36

Exhibit 9.19 Average Estimated Value per Salmonella Case Avoided (2007$) .................... 9-37

Exhibit 9.20 Estimated Annual Break-Even Threshold for Avoided Cases 

 of STEC O157.................................................................................................... 9-37

Exhibit 9.21 Estimated Annual Break-Even Threshold for Avoided Cases 

 of Salmonella .................................................................................................... 9-38 

10. References 
Economic Analysis for the Final RTCR xiii September 2012 

List of Acronyms 

A/CA Assessment and corrective action if necessary 

AGI Acute Gastrointestinal Illness 

AIDS Acquired Immune Deficiency Syndrome 

AIP Agreement in Principle 

ASDWA Association of State Drinking Water Administrators 

BMPs Best Management Practices 

CAs Corrective Actions 

CCR Consumer Confidence Report 

CDC Centers for Disease Control and Prevention 

CEA Cost Effectiveness Analysis 

COI Cost of Illness 

CWS Community Water System 

DBP Disinfection Byproduct 

DBPR Disinfection Byproducts Rule 

DisGW Disinfected Ground Water 

DisinfSW Disinfected Surface Water 

DV Data Verification 

EA Economic Analysis 

EC E. coli bacteria 

EC+ E. coli-positive 

ECI Employee Cost Index 

EO Executive Order 

EPA United States Environmental Protection Agency 

ERS Economic Research Service 

FAC Federal Advisory Committee 

FACA Federal Advisory Committee Act 

FC Fecal coliform bacteria 

FC+ Fecal Coliform-positive 

FDA U.S. Food and Drug Administration 

FR Federal Register

GW Ground Water 

GWR Ground Water Rule 

GWUDI Ground Water Under the Direct Influence of Surface Water 

HAA5 Five Haloacetic Acids 

HAV Hepatitis A Virus 

HEV Hepatitis E Virus 

HHS U.S. Department of Health and Human Services 

HUS Hemolytic Uremic Syndrome 

ICR Information Collection Rule 

ICR Information Collection Request 

IDSEs Initial Distribution System Evaluations 

IESWTR Interim Enhanced Surface Water Treatment Rule 

KRPEC Number of repeat TC-positive samples assayed that tested positive for EC 

KRPTC Number positive repeat samples during year 
Economic Analysis for the Final RTCR xiv September 2012 

KRTEC Number of routine TC-positive samples assayed that tested positive 

for EC 

KRTTC Number positive routine samples during year 

LRAAs Locational Running Annual Averages 

LT1ESWTR Long Term 1 Enhanced Surface Water Treatment Rule 

LT2ESWTR Long Term 2 Enhanced Surface Water Treatment Rule 

M/DBP Microbial/Disinfection By-Product 

M/Q/A Monthly, Quarterly, and Annual 

MAC Mycobacterium avium Complex 

MCL Maximum Contaminant Level 

MCLG Maximum Contaminant Level Goal 

MCMC Bayesian Markov Chain Monte Carlo 

MLEs Maximum Likelihood Estimates 

MRDLGs Maximum Residual Disinfectant Level Goals 

MRDLs Maximum Residual Disinfectant Levels 

NAICS North American Industry Classification System 

NCWS Non-Community Water System 

NDPWR National Primary Drinking Water Regulation 

NondisGW Nondisinfected ground water 

NPDWRs National Primary Drinking Water Regulations 

NRPEC Number of repeat TC-positive samples that were assayed for EC 

NRPTC Total number repeat samples assayed 

NRTEC Number of routine TC-positive samples that were assayed for EC 

NRTTC Number routine samples assayed 

NTNC Nontransient Noncommunity 

NTNCWS Nontransient Noncommunity Water System 

NTTAA National Technology Transfer and Advancement Act 

NTUs Nephelometric Turbidity Units 

O&M Operations and Maintenance 

OMB Office of Management and Budget 

PAM Primary Amoebic Meningioencephalitis 

PN Public Notification 

POU Point of Use 

pRPEC Repeat probability that a TC-positive repeat sample will also test ECpositive 

pRPTC Probability that a repeat sample will test positive 

pRTEC Probability that a TC-positive routine sample will also test EC-positive 

pRTTC Probability that a routine sample will test positive 

PWSs Public Water Systems 

RAA Running Annual Average 

RFA Regulatory Flexibility Act 

RPEC Repeat E. coli 

RPTC Repeat TC 

RTCR Revised Total Coliform Rule 

RTEC Routine E. coli

RTTC Routine TC 
Economic Analysis for the Final RTCR xv September 2012 

SAB Science Advisory Board 

SBA Small Business Administration 

SBREFA Small Business Regulatory Enforcement Fairness Act 

SDWA Safe Drinking Water Act 

SDWIS Safe Drinking Water Information System 

SDWIS/FED Safe Drinking Water Information System Federal Version 

Six Year Review Six Year Review of National Primary Drinking Water Regulations 

SS Sanitary survey 

STEC Shiga toxin-producing E. coli

SW Surface Water 

SWTR Surface Water Treatment Rule 

TC Total Coliform bacteria 

TC+ Total Coliform-positive 

TCR Total Coliform Rule 

TCRDSAC Total Coliform Rule/Distribution System Advisory Committee 

TMF Technical, Managerial, and Financial 

TNC Transient Noncommunity 

TNCWS Transient Noncommunity Water Systems 

TTHM Total Trihalomethane 

TWG Technical Work Group 

UMRA Unfunded Mandates Reform Act 

UV Ultraviolet light 

VSL Value of a Statistical Life 
Economic Analysis for the Final RTCR xvi September 2012 

Health Risk Reduction and Cost Analysis 

Under the Safe Drinking Water Act (SDWA) Amendments of 1996, when promulgating a 

national primary drinking water regulation that includes a maximum contaminant level (MCL), 

the U.S. Environmental Protection Agency (EPA) must conduct a health risk reduction and cost 

analysis (HRRCA). A HRRCA addresses seven requirements, all of which are addressed in this 

economic analysis (EA) for the final Revised Total Coliform Rule (RTCR). 

HRRCA Crosswalk Summary 

HRRCA Requirement Addressed in Economic Analysis 

Quantifiable and nonquantifiable health risk 

reduction benefits 

Chapter 6 (all sections) 

Chapter 8 (sections 8.8) 

Chapter 9 (sections 9.1.1, 9.2.2, and 9.3) 

Quantifiable and nonquantifiable health risk 

reduction benefits from co-occurring 

contaminants 

Chapter 6 (section 6.5.1, 6.5.4) 

Chapter 9 (section 9.2.2) 

Quantifiable and nonquantifiable costs Chapter 7 (all sections) 

Chapter 8 (sections 8.3–8.5, and 8.14) 

Chapter 9 (sections 9.1.2, 9.1.3, 9.2.2, and 9.3) 

Incremental costs and benefits associated 

with regulatory options 

Chapter 6 (sections 6.2 and 6.3) 

Chapter 7 (sections 7.4, 7.5, and 7.8) 

Chapter 9 (sections 9.1 and 9.3) 

Effects of the contaminants on the general 

population and sensitive subpopulations 

Chapter 2 (section 2.2) 

Chapter 6 (all sections) 

Chapter 8 (section 8.13) 

Chapter 9 (sections 9.1.1, 9.2.2, and 9.3) 

Increased health risk that may occur as a 

result of compliance 

Chapter 6 (section 6.2) 

Chapter 9 (section 9.1.1) 

Other relevant factors (quality and 

uncertainty of information) 

Chapter 4 (sections 4.2 and 4.3) 

Chapter 5 (section 5.3.3.1) 

Chapter 6 (section 6.4) 

Chapter 7 (section 7.7) 

Chapter 9 (section 9.2.1) 
Economic Analysis for the Final RTCR ES-1 September 2012 

Executive Summary 

This economic analysis (EA) presents the evaluation of the benefits and costs of the 

Revised Total Coliform Rule (RTCR). The analysis is performed in compliance with Executive 

Order 12866, Regulatory Planning and Review (58 Federal Register (FR) 51735, September 

1993), which requires the United States Environmental Protection Agency (EPA or Agency) to 

estimate the economic impact of rules that have an annual effect on the economy of over $100 

million. The Order further requires agencies to make the analysis for an “economically 

significant” rule available to the public in conjunction with publication of the proposed rule. 

Although EPA's analysis of the RTCR has determined that its annual costs are below this 

threshold, EPA has chosen to publish a complete EA for this rule. 

The revisions to the 1989 Total Coliform Rule (1989 TCR) are in accordance with the 

Safe Drinking Water Act (SDWA) as amended, which requires EPA to review and revise, as 

appropriate, each national primary drinking water regulation (NPDWR) promulgated under the 

SDWA at least every six years. In the Six-Year Review determination published in July 2003, 

EPA gave notice of its intent to review the 1989 TCR. EPA has since developed the proposed 

RTCR in collaboration with states, other interested stakeholders, and the Total Coliform 

Rule/Distribution System Advisory Committee (TCRDSAC), and then developed the final rule 

after assessing the comments received on the proposal. The Agency’s primary reasons for 

revising the 1989 TCR are implementation-related issues. The RTCR offers a meaningful 

opportunity for greater public health protection against fecal contamination and waterborne 

pathogens in the distribution systems of public water systems (PWSs) beyond the 1989 TCR. As 

with the 1989 TCR, the RTCR applies to all PWSs.

ES.1 Need for the Rule 

EPA promulgated the 1989 TCR to decrease the risk of waterborne illness. Among all 

SDWA rules promulgated for preventing waterborne illness, only the 1989 TCR applies to all 

PWSs, making the rule an essential component of the multi-barrier approach in public health 

protection against endemic (and epidemic) disease. The objectives of the 1989 TCR are: (1) to 

evaluate the effectiveness of treatment, (2) to determine the integrity of the distribution system, 

and (3) to signal the possible presence of fecal contamination. 

In recent years, the number of violations under the 1989 TCR has remained relatively 

steady, as shown in Exhibit 4.11 and discussed in Appendix G of the RTCR EA. EPA believes 

that this is reflective of a steady state among PWSs complying with the 1989 TCR; 

improvements likely to occur under that rule have largely been achieved. In outlining 

recommendations for further reductions in occurrence, in September 2008 EPA and the 

TCRDSAC developed the Agreement in Principle (AIP), which has become the basis for the 

structure of the RTCR. EPA published a proposed RTCR which was consistent with the 

recommendations in the AIP. As a result of public comments received some provisions of the 

RTCR were changed from the proposal. However, the final RTCR remains largely consistent 

with the recommendations in the AIP. 

In combination with the other SDWA rules, the RTCR will better address the 1989 TCR 

objectives and enhance the multi-barrier approach to protecting public health, especially with 
Economic Analysis for the Final RTCR ES-2 September 2012 

respect to small ground water PWSs. The RTCR maintains the three objectives of the 1989 TCR, 

but better addresses these objectives by requiring systems that may be vulnerable to fecal 

contamination (as indicated by their monitoring results) to do an assessment, to identify whether 

any sanitary defect(s) is (are) present, and to correct the defects. Therefore, greater public health 

protection is anticipated under the RTCR compared to the 1989 TCR because of its more 

preventive approach to identifying and fixing problems that affect or may affect public health. 

The key provisions of the rule are summarized in Section ES.3. 

Public health concerns, fecal contamination, and waterborne pathogens 

SDWA section 1412(b)(9) requires that any revision to an NPDWR “shall maintain, or 

provide greater, protection of the health of persons.” The RTCR aims to increase public health 

protection through the reduction of potential pathways of entry for fecal contamination into the 

distribution system. Since these potential pathways represent vulnerabilities in the distribution 

system whereby fecal contamination and/or waterborne pathogens, including bacteria, viruses, 

and parasitic protozoa could possibly enter the system, the reduction of these pathways in 

general should lead to reduced exposure and associated risk from the contaminants. Fecal 

contamination and waterborne pathogens can cause a variety of illnesses, including acute 

gastrointestinal illness (AGI) with diarrhea, abdominal discomfort, nausea, vomiting, and other 

symptoms. Most AGI cases are of short duration and result in mild illness. Other more severe 

illnesses caused by waterborne pathogens include hemolytic uremic syndrome (HUS) (kidney 

failure), hepatitis, and bloody diarrhea (WHO, 2004). Chronic disease such as irritable bowel 

syndrome, reduced kidney function, hypertension and reactive arthritis can result from infection 

by a waterborne agent (Clark et al., 2008). 

When humans are exposed to and infected by an enteric pathogen, the pathogen becomes 

capable of reproducing in the gastrointestinal tract. As a result, healthy humans shed pathogens 

in their feces for a period ranging from days to weeks. This shedding of pathogens often occurs 

in the absence of any signs of clinical illness. Regardless of whether a pathogen causes clinical 

illness in the person who sheds it in his or her feces, the pathogen being shed may infect other 

people directly by person-to-person spread, contact with contaminated surfaces, and other means 

which are referred to as secondary spread. As a result, pathogens that are initially waterborne 

may subsequently infect other people through a variety of routes (WHO, 2004). Sensitive 

subpopulations are at greater risk from waterborne disease than the general population (Gerba et 

al., 1996). 

Indicators

Total coliforms (TC) are a group of closely related bacteria that, with few exceptions, are 

not harmful to humans. Coliforms are abundant in the feces of warm-blooded animals, but can 

also be found in aquatic environments, in soil, and on vegetation. Coliform bacteria may be 

transported to surface water by runoff or to ground water by infiltration. TC bacteria are common 

in ambient water and may be injured by environmental stresses such as lack of nutrients, and 

water treatments such as chlorine disinfection, in a manner similar to most bacterial pathogens 

and many viral enteric pathogens (including fecal pathogens). EPA considers TC to be a useful 

indicator that a potential pathway exists through which fecal contamination can enter the 

distribution system. The absence (versus the presence) of TC in the distribution system indicates 
Economic Analysis for the Final RTCR ES-3 September 2012 

a reduced likelihood that fecal contamination and/or waterborne pathogens are occurring in the 

distribution system. 

Under the 1989 TCR, each total coliform-positive (TC+) sample is assayed for either 

fecal coliforms or E. coli. Fecal coliform bacteria are a subgroup of TCs that traditionally have 

been associated with fecal contamination. Since the promulgation of the 1989 TCR, more 

information and understanding of the suitability of fecal coliform and E. coli as indicators have 

become available. Study has shown that the fecal coliform assay is imprecise and too often 

captures bacteria that do not originate in the human or mammal gut (Edberg et al., 2000). On the 

other hand, E. coli is a more restricted group of coliform bacteria that almost always originate in 

the human or animal gut (Edberg et al., 2000). Thus, E. coli is a better indicator of fecal 

contamination than fecal coliforms. 

Presence of fecal contamination 

EPA believes that E. coli is a meaningful indicator for fecal contamination and the 

potential presence of associated pathogen occurrence. Fecal contamination is a very general term 

that includes all of the organisms found in feces, both pathogenic and nonpathogenic. Fecal 

contamination can occur in drinking water both through use of contaminated source water as 

well as direct intrusion of fecal contamination into the drinking water distribution system. 

Biofilms in distribution systems may harbor waterborne bacterial pathogens and accumulate 

enteric viruses and parasitic protozoa (Skraber et al., 2005; Helmi et al., 2008). Waterborne 

pathogens in biofilms may have entered the distribution system as fecal contamination from 

humans or animals. 

Co-occurrence of indicators and waterborne pathogens is difficult to measure. The 

analytical methods approved by EPA to assay for E. coli do not specifically identify most of the 

pathogenic E. coli strains. There are at least 700 recognized E. coli strains (Kaper et al., 2004). 

About 10 percent of recognized E. coli strains are pathogenic to humans (Feng, 1995; Hussein, 

2007; Kaper et al., 2004). Pathogenic E. coli include E. coli O157:H7, which is the primary 

cause of HUS in the United States (Rangel et al., 2005). The US Centers for Disease Control and 

Prevention (CDC) estimates that there are 73,000 cases of illness each year in the US due to E. 

coli O157:H7 (Mead et al., 1999). The CDC estimates that about 15 percent of all reported E. 

coli O157:H7 cases are due to water contamination (Rangel et al., 2005). Active surveillance by 

CDC shows that 6.3 percent of E. coli O157:H7 cases progress to HUS (Griffin and Tauxe, 

1991; Gould et al., 2009) and about 12 percent of HUS cases result in death within four years 

(Garg et al., 2003). About 4 to 15 percent of cases are transmitted within households by 

secondary transmission (Parry and Salmon, 1998). 

Because EPA-approved standard methods for E. coli do not typically identify the 

presence of the pathogenic E. coli strains, an E. coli-positive monitoring result is an indicator of 

fecal contamination but is not necessarily a measure of waterborne pathogen occurrence. 

Specialized assays and methods are used to identify waterborne pathogens, including pathogenic 

E. coli. 

One notable exception is the data reported by Cooley et al. (2007), which showed high 

concentrations of pathogenic E. coli strains in samples containing high concentrations of fecal 
Economic Analysis for the Final RTCR ES-4 September 2012 

indicator E. coli. These data are from streams and other poor quality surface waters surrounding 

California spinach fields associated with the 2006 E. coli O157:H7 foodborne outbreak. Data 

equivalent to these samples are not available from drinking water samples collected under the 

TCR. 

Waterborne disease outbreaks 

The CDC defines a waterborne disease outbreak as occurring when at least two persons 

(or one with amoebic meningoencephalitis) experience a similar illness after ingesting a specific 

drinking water contaminated with pathogens (or chemicals) (Kramer et al., 1996). The CDC 

maintains a database on waterborne disease outbreaks in the United States. The database is based 

upon responses to a voluntary and confidential survey form that is completed by state and local 

public health officials. 

The National Research Council strongly suggests that the number of identified and 

reported outbreaks in the CDC database for surface and ground waters represents a small 

percentage of actual number of waterborne disease outbreaks (NRC, 1997; Bennett et al., 1987; 

Hopkins et al., 1985 for Colorado data). Underreporting occurs because most waterborne 

outbreaks in community water systems are not recognized until a sizable proportion of the 

population is ill (Perz et al., 1998; Craun, 1996), perhaps 1 percent to 2 percent of the population 

(Craun, 1996). 

EPA drinking water regulations are designed to protect against endemic waterborne 

disease and to minimize waterborne outbreaks. In contrast to outbreaks, endemic disease refers 

to the persistent low to moderate level or the unusual ongoing occurrence of illness in a given 

population or geographic area (Craun, et al. 2006). 

ES.2 Consideration of Regulatory Options 

EPA evaluated the following three regulatory options as part of the regulatory 

development process: (1) 1989 TCR, (2) RTCR, and (3) Alternative option. EPA discusses the 

three regulatory options briefly in this executive summary and in greater detail in Chapter 3. 

The first regulatory option, the 1989 TCR, reflects EPA’s understanding of how the 1989 

TCR (USEPA, 1989, 54 FR 27544, June 29, 1989) is currently being implemented. That is, the 

1989 TCR is assumed to include “status quo” PWS and state implementation practices. The 

second regulatory option, which is the preferred regulatory option, is the RTCR. The RTCR is a 

revision of the 1989 TCR based on the recommendations of the advisory committee. The 

provisions of the preferred regulatory option are based on the AIP and are described in detail in 

section III of the preamble of the rule. The third regulatory option, the Alternative option, 

parallels the RTCR in most ways but includes variations of some of the provisions that were 

discussed by the advisory committee before consensus was reached on the AIP. Under the 

Alternative option, at the compliance date all PWSs are required to sample monthly for an initial 

period until they meet the eligibility criteria for reduced monitoring. EPA assumes that eligibility 

for reduced monitoring is determined during the next sanitary survey following the RTCR 

compliance date (corresponding to year 11 of the model runs presented later on in this EA). This 

more stringent approach differs from the RTCR that allows PWSs to continue to monitor at their 
Economic Analysis for the Final RTCR ES-5 September 2012 

current frequencies (with an additional annual site visit or voluntary Level 2 assessment 

requirement for PWSs wishing to remain on annual monitoring) until they are triggered into an 

increased sampling frequency. Under the Alternative option, no PWSs are allowed to reduce 

monitoring to an annual basis. EPA defined the Alternative option this way and included it in 

this EA to assess the relative impacts of a more stringent rule and to better understand the 

balance between costs and public health protection. 

To understand the relative impacts of the options, EPA gathered available data and 

information to develop and provide input into an occurrence and predictive model. EPA 

estimated both baseline conditions and changes to these conditions anticipated to occur over time 

as a result of these revised rule options. The analysis is described in more detail in the remainder 

of this EA. 

ES.3 Summary of the RTCR Requirements 

The RTCR maintains and strengthens the objectives of the 1989 TCR and is largely 

consistent with the recommendations in the AIP. The objectives are: (1) to evaluate the 

effectiveness of treatment, (2) to determine the integrity of the distribution system, and (3) to 

signal the possible presence of fecal contamination. The revised rule better addresses these 

objectives by requiring systems that may be vulnerable to fecal contamination (as indicated by 

their monitoring results) to do an assessment, to identify whether any sanitary defect(s) is (are) 

present, and to correct the defects. Therefore, greater public health protection is anticipated under 

the RTCR compared to the 1989 TCR because of its more preventive approach to identifying and 

fixing problems that affect or may affect public health. The following is an overview of the key 

provisions of the RTCR: 

MCLG and MCL for E. coli and coliform treatment technique for protection against potential 

fecal contamination 

The RTCR establishes a maximum contaminant level goal (MCLG) and maximum 

contaminant level (MCL) for E. coli. Under the RTCR there is no longer an MCL violation for 

multiple TC detections. The RTCR takes a preventive approach to protecting public health by 

establishing a coliform treatment technique for protection against potential fecal contamination. 

The treatment technique uses both TC and E. coli monitoring results to start an evaluation 

process that, where necessary, will require the PWS to conduct follow-up and corrective action 

that could prevent further incidences of contamination and exposure to fecal contamination 

and/or waterborne pathogens. See section III.B of the RTCR preamble (USEPA, 2010c) for a 

detailed discussion on the MCLG, MCL, and coliform treatment technique requirements. 

Monitoring 

As with the 1989 TCR, PWSs will continue to monitor for TC and E. coli according to a 

sample siting plan and schedule specific to the system. 

Sample siting plans under the RTCR must continue to be representative of the water 

throughout the distribution system. Under the RTCR, systems will have the flexibility to propose 

repeat sample locations that will best verify and determine the extent of potential contamination 

of the distribution system rather than having to sample within five connections upstream and 
Economic Analysis for the Final RTCR ES-6 September 2012 

downstream of the TC+ sample location. For some systems, most likely those that have limited 

or no distribution systems, the repeat samples may satisfy the requirement for source water 

samples. State approval is required because this constitutes a reduction in monitoring (no 

separate triggered source water samples), relative to requiring separate samples for compliance 

with the two rules. EPA believes that this reduction in monitoring is appropriate only if the state 

determines that the dual purpose sample provides public health protection equivalent to that 

provided by separate repeat and source water samples. On the other hand, EPA believes that dual 

purpose samples may not be appropriate for systems with extensive distribution systems because 

the reduction in monitoring (i.e., one less repeat sample in a distribution system that extends far 

from the source water sample site) may not provide public health protection equivalent to taking 

separate samples. 

As with the 1989 TCR, the RTCR allows reduced monitoring for some small ground 

water systems. The RTCR is expected to improve public health protection compared to the 1989 

TCR by requiring small ground water systems that are on or wish to move to reduced monitoring 

to meet certain eligibility criteria. Examples of the criteria include a sanitary survey showing that 

the system is free of sanitary defects, a clean compliance history for a minimum of 12 months, 

and a recurring annual site visit by the state and/or a voluntary Level 2 assessment by a party 

approved by the state, or meeting criteria established by the state. 

For small ground water systems, the RTCR requires increased monitoring for higher-risk 

systems that meet certain criteria such as unacceptable compliance history under the RTCR. The 

RTCR specifies conditions under which systems will no longer be eligible for reduced 

monitoring and will therefore be required to return to routine monitoring or to monitor at an 

increased frequency. 

The RTCR requires systems on a quarterly or annual monitoring frequency (applicable 

only to ground water systems serving 1,000 or fewer people) to conduct additional routine 

monitoring the month following one or more TC+ samples. Under the RTCR, systems must 

collect at least three routine samples during the next month, unless the state waives the additional 

routine monitoring. This is a reduction in the required number of additional routine samples from 

the 1989 TCR, which requires at least five routine samples in the month following a TC+ sample 

for all systems serving 4,100 or fewer people. 

The 1989 TCR requires all systems serving 1,000 or fewer people to collect at least four 

repeat samples while PWSs serving greater than 1,000 people to collect three repeat samples. 

The revised rule requires three repeat samples after a routine TC+ sample, regardless of the 

system type and size. 

Sections III.C and III.D of the RTCR preamble provide detailed discussions of the 

routine monitoring and repeat sampling requirements of the RTCR. 

Seasonal systems 

The RTCR establishes special monitoring requirements for seasonal systems for the first 

time. Seasonal systems represent a special case in that the shutdown and start-up of these water 

systems present additional opportunities for contamination to enter or spread through the 
Economic Analysis for the Final RTCR ES-7 September 2012 

distribution system. Seasonal systems must demonstrate completion of a state-approved start-up 

procedure. In addition, they must designate the time period(s) for monitoring based on sitespecific considerations (such as during periods of highest demand or highest vulnerability to 

contamination) in their state-reviewed sample siting plan. Section III.C.1.f of the RTCR 

preamble provides a detailed discussion of seasonal systems. 

Assessment and corrective action 

As part of a treatment technique, all PWSs are required to assess their systems when 

monitoring results show that the system may be vulnerable to contamination. Systems must 

conduct a simple self-assessment (Level 1) or a more detailed assessment (Level 2) depending on 

the level of concern raised by the results of the indicator sampling. The system is responsible for 

correcting any sanitary defect(s) found through either a Level 1 or Level 2 assessment. Section 

III.E of the RTCR preamble provides more discussion of the treatment technique requirement of 

the RTCR. 

Violations and public notification 

The RTCR establishes an E. coli MCL violation, a treatment technique violation, a 

monitoring violation, and a reporting violation. Public notification (PN) is required for each type 

of violation, depending on the degree of potential public health concern consistent with EPA’s 

current PN requirements under 40 CFR part 141, subpart Q. The RTCR also modifies the PN and 

consumer confidence report language to reflect the construct of the revised rule and the role of 

TC as an indicator of a potential pathway for the contamination of the distribution system. 

Sections III.F and III.G of the RTCR preamble provide detailed discussions of violations and PN 

under the RTCR. 

Transition to the RTCR 

The RTCR allows all systems to transition to the revised rule at their 1989 TCR 

monitoring frequency, including systems on reduced monitoring under the 1989 TCR. States will 

then evaluate whether the system is on an appropriate monitoring schedule by performing a 

special monitoring evaluation during each sanitary survey to review the status of the system, 

including the distribution system. The first such evaluation will be conducted during the first 

scheduled sanitary survey after the effective date of the rule; a system may remain on its 1989 

TCR monitoring schedule until this time unless it is triggered into more frequent monitoring. 

After its first evaluation, the state may allow the system to remain on its 1989 TCR monitoring 

schedule as long as the system meets the conditions for doing so. Initial grandfathering of 

monitoring frequencies reduces state burden by not requiring the state to determine appropriate 

monitoring frequency at the same time the state is working to adopt primacy, develop policies, 

and train their own staff and the PWSs in the state. 
Economic Analysis for the Final RTCR ES-8 September 2012 

Exhibit ES.1 shows the implementation schedule, from year 1 through year 10, for the 

RTCR. PWSs will begin sampling under the RTCR in the fourth year after RTCR promulgation.1

ES.4 Systems Subject to the RTCR 

The RTCR will apply to all PWSs in the United States. The baseline inventory for the EA 

is derived from EPA’s Safe Drinking Water Information System (SDWIS), fourth quarter 2007 

data (USEPA, 2007b),2 which contains information reported by primacy agencies on the 

approximately 155,000 active PWSs. The systems are subdivided by water source (ground water 

or surface water), type (community water systems (CWS), nontransient noncommunity water 

systems (NTNCWS), and transient noncommunity water systems (TNCWS)), and size (nine size 

categories ranging from those serving 100 or fewer people to those serving more than 1 million 

people). 

EPA developed the baseline water quality used in the RTCR EA from the Six-Year 

Review 2 data collected between 1998 and 2005, which include coliform monitoring data 

voluntarily provided to EPA by 37 primacy agencies (35 states and 2 tribes). The database 

consists of over nine million 1989 TCR records collected between 1998 and 2005. In addition, 

EPA incorporated information from the GWR, the U.S. Census, and the 1989 TCR to develop 

assumptions for the model. 

EPA used the available data and the requirements of the regulatory options considered to 

develop a model that predicts the number of systems in each category that experience TC+ and 

E. coli+ assays over the 25-year period of analysis. The results of the occurrence model and cost 

model indicate the number of systems that conduct the various activities under three regulatory 

options (1989 TCR, RTCR, and Alternative option). These results are discussed in terms of 

benefits of the current rule (changes in E. coli MCL violations incurred and corrective actions to 

be implemented) and rule costs in Section ES.5 below. 

ES.5 National Benefits and Costs of the RTCR 

The consensus resulting from TCRDSAC deliberations was that an RTCR consistent with 

the AIP would achieve a net risk reduction compared to the 1989 TCR. The committee applied 

best professional judgment in determining that the increased protection provided by the new 

requirements for implementing focused assessments and appropriate corrective actions would 

more than offset any potential increase in risk introduced by the reduction in samples or other 

changes resulting from the RTCR. 

 

1 Chapter 4 of the RTCR EA describes the baseline schedule under which systems would begin sampling following 

the RTCR effective date; Chapter 5 describes how the baseline schedule is adjusted, based on acute and non-acute 

violations incurred during an initial assessment period, to determine the steady state distribution of systems on 

monthly, quarterly, and annual sampling. 

2

 SDWIS/Federal Version (SDWIS/FED) is a database created by EPA containing data submitted by States and 

regions regarding inventory as well as compliance with SDWA regulations. 
Economic Analysis for the Final RTCR ES-9 September 2012 

Exhibit ES.1 Implementation Schedule 

Year 

Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year 9 Year 10 

State 

Implementation 

Revising Sample Siting 

Plan 

Routine Monitoring, Additional Routine Monitoring, Repeat Monitoring 

Annual Site Visits 

Level 1 and Level 2 Assessments 

Correction Actions Based on Level 1 and Level 2 Assessments 

Public Notification 

PWS 

Implementation 

Revising Sample Siting 

Plan 

Routine Monitoring, Additional Routine Monitoring, Repeat Monitoring 

Annual Site Visits 

Level 1 and Level 2 Assessments 

Correction Actions Based on Level 1 and Level 2 Assessments 

Public Notification 

Source: Final Information Collection Request for the Revised Total Coliform Rule, Figure 4.1. 

Note: Activities occurring in Year 10 continue throughout the remaining years of analysis 
Economic Analysis for the Final RTCR ES-10 September 2012

Based on limitations in available data (described further in Chapter 6, Section 6.4), EPA 

determined that benefits could not be calculated in terms of avoided cases of (or costs related to) 

morbidity or mortality. Since E. coli is an indicator of fecal contamination, EPA assumed that a 

decrease in E. coli occurrence in the distribution system would be associated with a decrease in 

fecal contamination in the distribution system. In general, this decrease in fecal contamination 

should reduce the potential risk to human health for PWS customers. Thus, any reduction in E. 

coli occurrence is considered a benefit of the RTCR. EPA’s qualitative analysis in Section 6.2 of 

this EA considers the overall changes in occurrence of contaminant indicators under the RTCR 

as compared to the 1989 TCR, and predicts a net decrease in risk. As discussed in Chapter 6, this 

reduction in risk is an indicator of the benefits of the RTCR. 

Sections ES.5.1 and ES.5.2 summarize the qualitative benefits analysis and the methods 

used to derive the costs of the rule, respectively. Section ES.5.1 describes the qualitative analyses 

of net changes in TC and E. coli occurrence anticipated to occur under the RTCR compared to 

the 1989 TCR. As found in Section ES.5.2, EPA’s national cost estimates include cost to 

implement the rule; revise sample siting plans; conduct routine monitoring, additional routine 

monitoring, and repeat monitoring; perform Level 1 and Level 2 assessments; implement 

corrective actions; and provide PN in the case of violations. Estimates for present value and 

annualized national costs are presented using a 3 percent and 7 percent discount rate.3 Chapters 6 

(benefits), 7 (costs), and 9 (comparison of benefits and costs), as well as the appendices, provide 

a more detailed discussion of all the analyses discussed in the sections below. 

Changes in risk associated with RTCR activities are characterized by their anticipated 

effects on potential pathways of contamination into PWS, as indicated by their effects on such 

pathways for TC/E. coli. These activities are considered under each rule component presented in 

Exhibit ES.3. 

ES.5.1 Derivation of Benefits 

In promulgating the RTCR, EPA expects to further reduce the risk of contamination of 

public drinking water from the current baseline risk under the 1989 TCR. The RTCR and 

Alternative option considered during development of this rule and analyzed as part of this EA 

(see Chapters 6, 7, and 9) are designed to achieve this reduction while maintaining public health 

protection in a cost-effective manner. 

The EA examines the benefits in terms of tradeoffs between compliance with the 1989 

TCR and the other options considered (RTCR and Alternative option). Because there are 

insufficient data reporting the co-occurrence in a single sample of fecal indicator E. coli and 

pathogenic organisms and because the available fecal indicator E. coli data from the Six-Year 

Review 2 dataset were limited to presence-absence data, EPA was unable to quantify health 

benefits for the RTCR. EPA used several methods to qualitatively evaluate the benefits of the 

 

3

There is much discussion among economists of the proper social discount rate to use for policy analysis. 

For RTCR cost analyses, calculations are made using two social discount rates (3 and 7 percent) thought to best 

represent current policy evaluation methodologies. Historically, the use of 3 percent is based on rates of return on 

relatively risk-free investments, as described in the Guidelines for Preparing Economic Analyses (USEPA, 2000b). 

The rate of 7 percent is a recommendation of the Office of Management and Budget (OMB) as an estimate of 

“before-tax rate of return to incremental private investment” (OMB, 1996).
Economic Analysis for the Final RTCR ES-11 September 2012

RTCR and Alternative option. The qualitative evaluation uses both the judgment of EPA as 

informed by the TCRDSAC deliberations as well as quantitative estimates of changes in TC

occurrence and counts of systems implementing corrective actions. The evaluation characterizes, 

in relative terms, the reduction in risk for each regulatory option as compared to baseline 

conditions. 

As presented in the description of the baseline (see Chapter 4), the percentages of 

samples that are positive TC and E. coli are generally higher for PWSs serving 4,100 or fewer 

people than those serving more than 4,100 people. PWSs with higher TC and E. coli occurrence 

are more likely to be triggered into assessments and corrective action. As discussed previously, 

EPA believes that the assessments and corrective action will lead to a decrease in TC and E. coli 

occurrence. Because the PWSs serving 4,100 or fewer people have a higher initial E. coli

occurrence and will be triggered into more assessments and corrective actions than larger PWSs, 

the increase in benefits for these small systems will likely be more evident as compared to the 

larger systems. In particular, model results suggest that customers of small ground water 

TNCWSs serving 100 or fewer people, which constitute approximately 40 percent of PWSs, 

experience the most improvement in water quality under the RTCR. That is, the occurrence of E. 

coli is predicted to decrease more for these systems that for other systems types. 

When revising an existing drinking water regulation, one of the main concerns is to 

ensure that backsliding on water quality and public health protection does not occur. SDWA 

requires that EPA at least maintain or improve public health protection for any rule revision. 

EPA believes that the RTCR is more stringent than the 1989 TCR with regard to protecting 

public health. The basis for this perspective is provided in chapters 6 and 9 of this EA. 

Risk reduction for the RTCR is characterized by the activities performed that are 

presumed to reduce risk of exposing the public to contaminated water. These activities are 

considered under each rule component presented in Exhibit ES.3. 

More frequent monitoring has the potential to decrease the risk of contamination in PWSs 

based on an enhanced ability to diagnose and mitigate system issues in a more timely fashion. 

Conversely, less frequent monitoring has the potential to increase risk. Real-time continuous 

sampling would mitigate the most risk possible based on sampling schedule; however, it would 

cost prohibitively more than the periodic sampling practiced under the 1989 TCR and included in 

the RTCR and the Alternative option. EPA’s objective in revising the sampling schedules 

included in the RTCR and Alternative option was to find an appropriate balance between the 

factors of risk mitigation and cost management. 

Under the RTCR and Alternative option, the reduction in the number of repeat samples 

and additional routine samples for some PWSs has the potential to contribute to increased risk 

for PWS customers. However, this increase in risk is expected to be more than offset by potential 

decreases in risk from increased routine samples and the addition of the assessments and 

corrective action provisions that find and fix problems indicated by monitoring. Exhibit ES.2 

illustrates the predicted reduced frequency at which TC occur subsequent to the implementation 

of the RTCR and Alternative option. As discussed previously, the RTCR uses TC and E. coli

occurrence as an indicator of potential pathways for possible contamination to enter the 

distribution system. Exhibit ES.2 illustrates the combined effects on TC occurrence resulting 
Economic Analysis for the Final RTCR ES-12 September 2012

from changes in monitoring and the effects of assessments and corrective actions for the different 

rule options illustrated. The relative trends indicated in Exhibit ES.2 for small transient 

noncommunity ground water systems also pertain to other PWS categories as illustrated in 

Chapter 5. EPA chose to include the characterization for this set of TNCWSs because they 

represent the system category of largest influence on the national impacts. 

Exhibit ES.2 Modeled TC+ Occurrence in Transient Noncommunity Ground Water 

Systems Serving ≤ 4,100 

Notes: 

1) Six Year 2005 TC+ occurrence is representative of all GW TNCWS. The rate presented may 

underestimate the occurrence for systems serving 25–4,100 individuals. 

2) Graph shows the 30-year modeled period discussed in Ch. 5. Model years 3–27 represent the 25-year 

period of analysis for this EA. Model year 11 begins the steady state, during which systems that qualified for 

reduced monitoring are now sampling on their reduced schedules. The criteria and timing of this monitoring 

adjustment is discussed in Section 5.3.2.2 of this EA. 

3) The results represented by the curves for 1989 TCR and RTCR and Alternative options all incorporate the 

effects of the GWR. 
Economic Analysis for the Final RTCR ES-13 September 2012 

Exhibit ES.3 Potential Changes in Risk under the RTCR and Alternative Option Relative to the 1989 TCR 

Rule Component Factors Leading to a Potential 

Increase in Risk

Factors Leading to a Potential Decrease in 

Risk

Overall Predicted Change in 

Risk

RTCR Alternative 

option RTCR Alternativeoption RTCR Alternative option 

Implementation 

Activities

None None None None No change No change

Routine 

Monitoring 

(Including 

Reduced 

Monitoring)

None None Increased stringency

in requirements to 

qualify for reduced 

monitoring along with 

requirement to return 

to baseline monitoring 

upon loss of these 

criteria is expected to 

result in decreased 

risk (i.e., PWSs that 

qualify for reduced 

monitoring will be 

better operated, PWSs 

that no longer qualify 

will monitor more 

frequently).

PWSs all monitor monthly 

in the first few years of 

implementation of the 

RTCR, which is an 

increase in sampling 

frequency for systems 

that monitor quarterly or 

annually under the 1989

TCR. After the first few 

years, systems may 

reduce to quarterly, but 

none may reduce to 

annual monitoring, 

creating a decrease in risk 

for systems on annual 

monitoring under the 1989

TCR.

Decrease Decrease

Repeat 

Monitoring

Required repeat 

samples reduced 

from 4 to 3 for 

systems serving 

≤1,000 people 

Required repeat 

samples reduced 

from 4 to 3 for 

systems serving 

≤1,000 people 

None None Increase Increase

Additional 

Routine 

Monitoring

Additional routine 

samples are no 

longer required for 

PWSs monitoring 

monthly.

Additional routine 

samples are no 

longer required 

for PWSs 

monitoring 

monthly.

None None Increase Increase
Economic Analysis for the Final RTCR ES-14 September 2012 

Rule Component Factors Leading to a Potential 

Increase in Risk

Factors Leading to a Potential Decrease in 

Risk

Overall Predicted Change in 

Risk 

RTCR Alternative 

option RTCR Alternativeoption RTCR Alternative option

GW PWSs serving 

≤1,000 people 

would reduce 

additional routine 

samples from 5 to 

3.

GW PWSs 

serving ≤1,000 

people would 

reduce additional 

routine samples 

from 5 to 3.

Annual Site Visits None (only states 

currently 

performing annual 

site visits are 

expected to 

continue)

Annual 

monitoring is not 

permitted under 

the Alternative 

option so annual 

site visits will no 

longer be 

conducted.

None (only states 

currently performing 

annual site visits are 

expected to continue)

None No change Increase

Assessments None None Mandatory 

assessments are a 

new requirement.

Mandatory assessments 

are a new requirement.

Decrease Decrease

Corrective 

Actions

None None Mandatory corrective 

actions are a new 

requirement. 

Mandatory corrective 

actions are a new 

requirement. 

Decrease Decrease

Public 

Notification—

Monthly/NonAcute MCL 

Violations

Reduction in 

available public 

information

Possible PWS 

complacency

Reduction in 

available public 

information

Possible PWS 

complacency

Less confusion (PN 

more in line with 

potential health risks)

PWS resources used 

more efficiently

Less confusion (PN more 

in line with potential 

health risks)

PWS resources used 

more efficiently

Unknown Unknown

Public 

Notification—

Monitoring and 

Reporting 

Violations

None None Improved focus of 

required PN for rule 

aspects with potential 

adverse health 

consequences, 

notably E. coli MCL 

Improved focus of 

required PN for rule 

aspects with potential 

adverse health 

consequences, notably E. 

coli MCL violations and 

Decrease Decrease
Economic Analysis for the Final RTCR ES-15 September 2012

Rule Component Factors Leading to a Potential 

Increase in Risk

Factors Leading to a Potential Decrease in 

Risk

Overall Predicted Change in 

Risk

RTCR Alternative 

option RTCR Alternativeoption RTCR Alternative option

violations and failure 

to conduct 

assessments and 

corrective actions, will 

motivate PWSs to 

conduct sampling and 

other treatment 

technique 

requirements.

failure to conduct 

assessments and 

corrective actions, will 

motivate PWSs to 

conduct sampling and 

other treatment technique 

requirements.

Overall Decrease Decrease

Note:

1) Detailed discussion of the rationale for determinations of potential risk for each rule component is presented in Ch. 6 (Section 6.2) of this EA. Implementation 

activities consist of administrative activities by PWSs and states to implement the rule.

2) Assessment of potential changes in risk for monitoring components is an overall assessment. Potential changes (or static state) of risk for particular system 

sizes and types differ according to individual regulatory requirements and are discussed in Section 6.2. Chapter 3 provides a detailed description of the

regulatory components for all three regulatory options, and the preamble to the RTCR provides additional discussion of the TCRDSAC process and the rationale 

underlying the structure of the regulatory options considered.
Economic Analysis for the Final RTCR ES-16 September 2012

The effect that the changes to PN requirements under the 1989 TCR for monthly/nonacute MCL violations have on risk is difficult to predict. Some factors, such as reduction in 

available public information and possible PWS complacency, lead to a potential increase in risk 

and other factors, such as less confusion (PN more in line with potential health risks) and PWSs 

resources used more efficiently, lead to a potential decrease, as discussed in Chapter 9. This 

change to PN is addressing a key concern expressed by various stakeholders in the advisory 

committee and during the Six-Year Review 1 comment solicitation process. By eliminating the 

requirement and replacing it with assessment and corrective action requirements, the Agency 

expects less public confusion, more effective use of resources, increased transparency, and 

increased public health protection. Other rule components are expected to have a negligible 

effect on risk. However, the overall effect of the RTCR is expected to be a further reduction in 

risk from the current baseline risk under the 1989 TCR. Chapter 6 presents a detailed discussion 

of the potential influence on health risk for each rule component. 

Although a qualitative analysis is the primary method employed for analyzing potential 

changes in risk, some quantitative measures are considered in the overall assessment of the 

RTCR, as presented in Chapter 9 of the RTCR EA. In particular, EPA developed a model to 

describe TC and E. coli occurrence in water systems for the 1989 TCR (baseline for this EA) and 

the RTCR and Alternative option. The model generates estimates of reduced TC and E. coli 

occurrence based on requirements of the RTCR and Alternative option to perform assessments 

and corrective actions not explicitly required in the 1989 TCR. In addition, the model takes into 

account in the baseline for the 1989 TCR the reductions attributable to the implementation of the 

GWR, which was effective as of December 2009. The predictive occurrence model and analyses 

results are discussed further in Chapters 5, 6, and 9. 

Exhibit ES.4 presents the annual number of acute violations (1989 TCR) and E. coli

MCL violations (RTCR and Alternative option) as predicted by the RTCR occurrence model in 

Year 9. By Year 9, PWSs that are expected to meet the criteria for reduced monitoring begin 

reduced monitoring, and the distribution of PWSs that monitor monthly, quarterly, and annually 

is assumed to remain relatively constant. EPA did not quantify changes in violation or trigger 

rates for systems serving more than 4,100 people among the 1989 TCR, RTCR, and Alternative 

option because of: (1) limited Six-Year Review data to characterize these systems, (2) the 

essentially unchanged monitoring requirements across options for these systems, and (3) the 

level of effort already occurring to implement the 1989 TCR. 

The estimates of E. coli MCL violations have two major drivers: the total number of 

samples taken over time (including routine, additional routine, and repeat) and the impact of 

corrective actions taken. When looking at the comparisons between the 1989 TCR with the 

RTCR across all PWSs, the overall impact of the total numbers of samples taken is negligible 

because the total number of samples predicted to be taken throughout the period of analysis is 

almost the same (approximately 82 million samples) under both the 1989 TCR and the RTCR.

For the Alternative option, the analysis predicts that 88 million total samples will be taken over 

the period of analysis. 

The changes in the steady state estimates of annual E. coli MCL violations from the 1989

TCR to the RTCR and Alternative option are shown in Exhibit 6.5. The steady state in the model 

refers to the period beginning in years 7 (CWSs) and 9 (NCWSs) following promulgation, after 
Economic Analysis for the Final RTCR ES-17 September 2012

the proportions of systems sampling on monthly, quarterly, or annual regimens are adjusted 

following a period of assessment.4Systems that qualify for reduced monitoring will begin their 

new regimens in years 7 and 9 after promulgation, respectively, for CWSs and NCWSs. The 

annual number of acute violations (1989 TCR) and E. coli MCL violations (RTCR and 

Alternative option) shown in Exhibit ES.4 for small systems are from the predictive model and 

reflect the estimates for Year 9 of the 25-year period of analysis.

The steady state reductions in the number of annual E. coli MCL violations found under 

the RTCR and Alternative option primarily reflect the benefits of corrective actions under these 

two options in preventing many of the E. coli MCL violations that would otherwise occur over 

this period. Under the RTCR, reductions (or no increases) are predicted for all PWS sizes and 

types, while under the Alternative option, reductions (or no increases) are predicted for all PWSs 

except TNCWSs serving ≤1,000 people. For these small TNCWSs under the Alternative option, 

increased monitoring is expected to lead to an overall increase in annual E. coli MCL violations 

(and is also the driver of the greater total number of annual E. coli MCL violations predicted). 

The interplay of the reducing effect on E. coli MCL violations that required corrective actions 

induce and the increasing effect from reductions in some monitoring requirements are explored 

in Section 6.4 of this EA. The step-wise analysis presented in Section 6.4 shows how E. coli

MCL violations could increase under the Alternative option and concludes that, on balance, more 

E. coli MCL events are prevented than are missed. 

 

4

 The effective date of the RTCR occurs after 3 years of implementation, at the start of year 4 post-promulgation. 

For CWSs, years 4–6 post-promulgation are the period of assessment for considering potential to move to reduced 

monitoring for systems; for NCWSs, years 4–8 are the period of assessment. 
Economic Analysis for the Final RTCR ES-18 September 2012

Exhibit ES.4 Predicted Annual Number of Acute (1989 TCR) or E. coli MCL 

(RTCR and Alternative Option) Violations by Regulatory Option and System Type 

(Year 9)1 

A B C D

Community Water Systems (CWSs) - SW

≤100 1,170 7 5 5

101 - 500 2,150 7 8 8

501-1,000 1,173 5 4 4

1,001-4,100 2,938 8 7 7

4,101-33,000 3,164 9 9 9

33,001-96,000 720 3 3 3

96,001-500,000 308 1 1 1

500,001-1 Million 31 - - -

> 1 Million 17 - - -

Totals 11,671 39 36 36

Community Water Systems (CWSs) - GW

≤100 11,938 58 41 40

101 - 500 13,892 40 35 36

501-1,000 4,467 13 7 8

1,001-4,100 6,443 26 15 15

4,101-33,000 3,156 12 12 12

33,001-96,000 335 2 2 2

96,001-500,000 63 0 0 0

500,001-1 Million 4 - - -

> 1 Million 3 - - -

Totals 40,301 151 113 114

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

≤100 250 2 1 1

101 - 500 253 2 1 1

501-1,000 88 0 0 0

1,001-4,100 72 1 1 1

4,101-33,000 22 - - -

33,001-96,000 2 - - -

96,001-500,000 1 - - -

500,001-1 Million - - - -

> 1 Million - - - -

Totals 688 5 3 3

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

≤100 8,826 43 25 22

101 - 500 6,613 19 13 16

501-1,000 1,718 4 3 4

1,001-4,100 812 8 4 4

4,101-33,000 70 0 0 0

33,001-96,000 2 - - -

96,001-500,000 - - - -

500,001-1 Million - - - -

> 1 Million - - - -

Totals 18,041 74 46 47

Transient Noncommunity Water Systems (TNCWSs) - SW

≤100 1,339 18 11 11

101 - 500 497 7 3 3

501-1,000 88 1 1 1

1,001-4,100 67 2 1 1

4,101-33,000 18 - - -

33,001-96,000 - - - -

96,001-500,000 - - - -

500,001-1 Million - - - -

> 1 Million 1 - - -

Totals 2,010 29 16 16

Transient Noncommunity Water Systems (TNCWSs) - GW

≤100 60,200 339 237 279

101 - 500 19,275 96 69 95

501-1,000 1,963 11 9 8

1,001-4,100 617 8 5 5

4,101-33,000 67 0 0 0

33,001-96,000 2 - - -

96,001-500,000 1 - - -

500,001-1 Million 1 - - -

> 1 Million - - - -

Totals 82,126 454 321 388

Grand Total 154,837 751 535 605

Alternative 

Option

PWS Size

(Population

Served)

Number of 

Systems 1989 TCR RTCR

Source: Output from RTCR models (described in Sections 5.3 and 5.4 of this EA). 

Notes: 

1) For modeling purposes, additional routine sample counts include regular routine 

samples taken in the same month. 

2) Detail may not add due to independent rounding. 
Economic Analysis for the Final RTCR ES-19 September 2012

ES.5.2 Derivation of Costs

Costs are estimated for different PWS types and size categories (nine size categories are 

used based on population served) using unit costs obtained from the advisory committee 

technical work group and vendors and presented in the Technology and Cost Document for the 

Final Revised Total Coliform Rule (USEPA, 2010d). Cost analyses for PWSs include estimates 

to implement the rule; to revise sample siting plans; to conduct routine monitoring, additional 

routine monitoring, and repeat monitoring; to perform Level 1 and Level 2 assessments and 

implement corrective actions; and to provide PN in the case of violations. State cost analyses 

include estimates of the labor burdens that states would incur, including staff training on RTCR 

requirements, conducting annual administration, reviewing monitoring reports, reviewing and 

approving corrective action plans, and for recordkeeping. Chapter 7 of this EA provides detailed 

discussion on the underlying cost-buildup for each rule component included in the cost model.

National costs are estimated using a cost model specifically developed for the RTCR. The 

model builds on the occurrence model described in Chapter 5. Within the modeling structure, 

costs for PWSs serving more than 4,100 retail customers are analyzed differently from smaller 

PWSs to capture differing baseline structures and to account for differences in available 

occurrence data as described in Chapter 4 of this EA. The resulting national cost estimates for 

the RTCR regulatory options considered are shown in Exhibit ES.5. To evaluate the impact of 

costs under the RTCR, emphasis in this EA is placed on the net changes in costs of the RTCR or 

Alternative option compared to the 1989 TCR (i.e., incremental costs over the 1989 TCR), also 

shown in Exhibit ES.5. 

As noted throughout the RTCR EA, there is variability among many of the input 

parameters to the cost model and several rule compliance assumptions based on PWS size and 

type (e.g., population served, labor rates, TC hit rates, and occurrence distributions are different 

for different sizes and types of PWSs). However, there is insufficient information to fully 

characterize the distribution of variability (i.e., calculating confidence bounds) within each of 

these PWS classifications on a national scale; therefore, EPA uses mean values for these input 

parameters.

EPA also recognizes that there is uncertainty in the national cost estimates. Many of the 

uncertainties have the same impact on both the 1989 TCR and RTCR and Alternative options

(e.g., baseline assumptions and effects of GWR implementation). Because the EA analyses focus 

on net changes between the 1989 TCR and the RTCR and Alternative option, these common 

sources of uncertainty do not impact conclusions based on the net change analyses. For 

assumptions that are major drivers of the analyses and differ between the 1989 TCR and RTCR

and Alternative option (e.g., corrective action compliance forecast), EPA has evaluated 

uncertainty and performed sensitivity analyses to qualitatively and quantitatively characterize the 

potential impacts of alternative input parameters. Chapters 4 and 5 present a comprehensive 

discussion of factors contributing uncertainty to the occurrence analysis. Chapter 5 presents a 

sensitivity analysis pertaining to the predictive occurrence model results, which also impact the 

cost calculations. Section 7.7 of the EA discusses uncertainty and provides sensitivity analysis 

results as they specifically pertain to the cost analyses.
Economic Analysis for the Final RTCR ES-20 September 2012

 Exhibit ES.5 Comparison of Total and Net Change from 1989 TCR in Annualized 

Present Value Costs ($Millions, 2007$) 

PWSs State Total PWSs State Total

1989 TCR - Total $ 185 0.9$ $ 186 $ 178 $ 0.9 $ 179

RTCR - Total $ 199 1.1$ $ 200 $ 192 $ 1.3 $ 193

RTCR - Net Change $ 1 4 0.1$ $ 1 4 $ 1 4 $ 0.4 $ 1 4

RTCR - Percent Change 8% 16% 8% 8% 48% 8%

Alternative Option - Total $ 214 1.2$ $ 216 $ 209 $ 1.5 $ 210

Alternative Option - Net Change $ 2 9 0.3$ $ 3 0 $ 3 1 $ 0.6 $ 3 2

Alternative Option - Percent Change 16% 34% 16% 17% 69% 18%

3% Discount Rate 7% Discount Rate

Source: RTCR cost model. 

Notes: 

1) Detail may not add due to independent rounding. 

2) Annualized costs for the state are greater using the 7% than 3% discount rate for the RTCR and Alternative 

option. This occurs because the costs under the RTCR and Alternative option are frontloaded in the 25-year time 

period due to the all-monthly sampling requirement (which doesn’t occur under the 1989 TCR). Discounting a 

given stream using 3% and 7% will always result in a higher present value using 3%; annualization of an 

identical value (any value) using 3% and 7% would result in a higher value under 7%. Depending on how costs 

accrue over the period, and how long the period is, one effect will be stronger than the other. Generally, the 

discounting effect is stronger, resulting in the pattern commonly seen where the 3% annualized amount is 

greater than the 7% one. However, in cases like the Alternative option where the costs accrue faster early in the 

time period, the annualization effect can more than compensate for the discounting effect, resulting in a higher 

annualized value under 7% compared to 3%. 

ES.6 Projected Impacts on Household Costs 

The household cost analysis considers the impact that the costs incurred by CWSs have 

on the households they serve. This analysis considers the potential increase in a household’s 

annual water bill if a CWS passed the entire cost increase resulting from the rule on to their 

customers. This analysis is a tool to gauge potential impacts and should not be construed as a 

precise estimate of potential changes to household water bills. State costs and costs to TNCWSs 

and NTNCWSs are not included in this analysis since their costs are not typically passed through 

directly to households. Exhibit ES.6 presents the mean expected increases in annual household 

costs for all CWSs, including those systems that do not have to take corrective action. Exhibit 

ES.6 also presents the same information for CWSs that must take corrective action. Household 

costs tend to decrease as system size increases, due mainly to the economies of scale for the 

corrective actions. 

The first section of Exhibit ES.6 presents net costs per household under the RTCR and 

Alternative option for all rule components spread across all CWSs. In this scenario, comparison 

to the 1989 TCR shows a cost savings for households in the largest size category. For those 

households that are expected to see a cost increase, the average annual water bill would be 

expected to increase by less than ten cents on average. 

While the average increase in annual household water bills to implement the RTCR is 

less than a dollar, customers served by a small CWS that have to take corrective actions as a 

result of the rule would incur slightly larger increases in their water bills. The subsequent 

sections of the exhibit present net costs per household for three different subsets of CWSs 

(CWSs that perform assessments but no corrective actions, CWSs that do perform corrective 
Economic Analysis for the Final RTCR ES-21 September 2012

actions, and CWSs that do not perform assessments or corrective actions). As shown in the 

second section of Exhibit ES.6, approximately 67% of households are served by CWSs that 

would perform assessments but would not perform corrective actions (because no sanitary 

defects are found). The 9% of households belonging to CWSs that would perform corrective 

actions would experience an increase in annual net household costs of less than $1 on average for 

CWSs serving >4,100 people to approximately $26 for CWSs serving 100 people or fewer. 

The final section of Exhibit ES.6 presents the 24% of households belonging to CWSs that 

would not perform assessments or corrective actions. Households of this category would 

experience an increase in cost savings when compared to those performing corrective actions, 

and a decrease in cost savings when compared to those performing assessments but no corrective 

actions. This decrease in costs savings is because no PN costs are associated with systems not 

performing assessments. Overall, the main driver of additional household costs under the RTCR 

is whether or not additional corrective actions are performed. 
Economic Analysis for the Final RTCR ES-22 September 2012

Exhibit ES.6 Summary of Net Annual Per-Household Costs for the RTCR (2007$)

RTCR Net

RTCR Net Cost per 

Household

Alternative 

Option Net

Alternative 

Option Net 

Cost per 

Household RTCR Net

RTCR Net 

Cost per 

Household

Alternative 

Option Net

Alternative 

Option Net 

Cost per 

Household

A B C D=C/A E F=E/B G H=G/A I J=I/B

≤100 307,243 307,243 $ 111,694 $ 0.364 $ 225,693 $ 0.735 $ 207,140 0.674$ $ 348,782 $ 1.135

101-500 1,589,510 1,589,510 $ 371,004 $ 0.233 $ 464,207 $ 0.292 $ 471,664 0.297$ $ 598,244 $ 0.376

501-1,000 1,624,853 1,624,853 $ 46,687 $ 0.029 $ 87,294 $ 0.054 $ 96,473 0.059$ $ 148,274 $ 0.091

1,001-4,100 7,816,592 7,816,592 $ 371,294 $ 0.048 $ 371,294 $ 0.048 $ 418,935 0.054$ $ 418,935 $ 0.054

4,101-33,000 27,997,647 27,997,647 $ 2,385,056 $ 2,385,056 0.085 $ $ 2,083,266 0.085 $ 0.074$ 2,083,266 $ $ 0.074

33,001-96,000 21,933,438 21,933,438 $ 1,532,410 $ 1,532,410 0.070 $ $ 1,273,202 0.070 $ 0.058$ 1,273,202 $ $ 0.058

96,001-500,000 26,770,609 26,770,609 $ 1,479,280 $ 1,479,280 0.055 $ $ 1,214,316 0.055 $ 0.045$ 1,214,316 $ $ 0.045

500,001-1 Million 9,764,979 9,764,979 $ 157,138 $ 0.016 $ 157,138 $ 0.016 $ 125,671 0.013$ $ 125,671 $ 0.013

> 1 Million 16,309,853 16,309,853 $ (2,223) $ (0.000) $ (2,223) $ (0.000) $ (1,479) (0.000)$ $ (1,479) $ (0.000)

Total 114,114,724 114,114,724 $ 6,452,342 $ 6,700,151 0.057 $ $ 5,889,190 0.059 $ 0.052$ 6,209,211 $ $ 0.054

≤100 125,340 124,920 $ (185,923) $ (1.483) $ (149,283) $ (1.195) $ (125,037) (0.998)$ $ (75,885) $ (0.607)

101-500 460,577 464,568 $ (137,193) $ (0.298) $ (103,168) $ (0.222) $ (82,657) (0.179)$ $ (40,057) $ (0.086)

501-1,000 394,643 401,009 $ (133,453) $ (0.338) $ (123,890) $ (0.309) $ (111,147) (0.282)$ $ (98,598) $ (0.246)

1,001-4,100 2,341,578 2,341,578 $ (262,222) $ (0.112) $ (262,222) $ (0.112) $ (213,247) (0.091)$ $ (213,247) $ (0.091)

4,101-33,000 24,827,588 24,827,588 $ (195,108) $ (0.008) $ (195,108) $ (0.008) $ (76,420) (0.003)$ $ (76,420) $ (0.003)

33,001-96,000 19,232,570 19,232,570 $ (173,238) $ (0.009) $ (173,238) $ (0.009) $ (142,573) (0.007)$ $ (142,573) $ (0.007)

96,001-500,000 23,912,325 23,912,325 $ (146,682) $ (0.006) $ (146,682) $ (0.006) $ (131,967) (0.006)$ $ (131,967) $ (0.006)

500,001-1 Million 5,524,188 5,524,188 $ (40,160) $ (0.007) $ (40,160) $ (0.007) $ (36,993) (0.007)$ $ (36,993) $ (0.007)

> 1 Million - - $ - $ - $ - $ - $ - $ - $ - $ - 

Total 76,818,809 76,828,746 $ (1,273,980) $ (1,193,752) (0.017) $ $ (0.016) $ (920,040) (0.012)$ $ (815,739) $ (0.011)

≤100 13,927 13,880 $ 365,576 $ 26.250 $ 388,703 $ 28.004 $ 330,235 23.712$ $ 353,002 $ 25.432

101-500 51,175 51,619 $ 516,102 $ 10.085 $ 508,146 $ 9.844 $ 452,342 8.839$ $ 450,070 $ 8.719

501-1,000 43,849 44,557 $ 178,205 $ 4.064 $ 181,189 $ 4.066 $ 155,596 3.548$ $ 158,538 $ 3.558

1,001-4,100 260,175 260,175 $ 590,719 $ 2.270 $ 590,719 $ 2.270 $ 512,568 1.970$ $ 512,568 $ 1.970

4,101-33,000 3,170,059 3,170,059 $ 2,605,551 $ 2,605,551 0.822 $ $ 2,198,499 0.822 $ 0.694$ 2,198,499 $ $ 0.694

33,001-96,000 2,700,868 2,700,868 $ 1,709,801 $ 1,709,801 0.633 $ $ 1,424,758 0.633 $ 0.528$ 1,424,758 $ $ 0.528

96,001-500,000 2,858,284 2,858,284 $ 1,625,742 $ 1,625,742 0.569 $ $ 1,346,704 0.569 $ 0.471$ 1,346,704 $ $ 0.471

500,001-1 Million 613,799 613,799 $ 195,076 $ 0.318 $ 195,076 $ 0.318 $ 161,185 0.263$ $ 161,185 $ 0.263

> 1 Million - - -$ $ - -$ -$ -$ -$ -$ -$ 

Total 9,712,136 9,713,240 $ 7,786,773 $ 7,804,928 0.802 $ $ 6,581,888 0.804 $ 0.678$ 6,605,324 $ $ 0.680

≤100 167,976 168,442 (67,959) $ (0.405) (13,728) $ (0.081) 1,943 0.012$ 71,665 $ 0.425

101-500 1,077,758 1,073,324 (7,905) $ (0.007) 59,230 $ 0.055 101,979 0.095$ 188,231 $ 0.175

501-1,000 1,186,361 1,179,288 1,936 $ 0.002 29,995 $ 0.025 52,024 0.044$ 88,334 $ 0.075

1,001-4,100 5,214,839 5,214,839 42,797 $ 0.008 42,797 $ 0.008 119,614 0.023$ 119,614 $ 0.023

4,101-33,000 - - - $ - - -$ - -$ - -$ 

33,001-96,000 - - - $ - - -$ - -$ - -$ 

96,001-500,000 - - - $ - - -$ - -$ - -$ 

500,001-1 Million 3,626,992 3,626,992 - $ - - -$ - -$ - -$ 

> 1 Million 16,309,853 16,309,853 - $ - - -$ - -$ - -$ 

Total 27,583,779 27,572,738 $ (31,132) $ (0.001) $ 118,294 $ 0.004 $ 275,560 0.010$ $ 467,844 $ 0.017

Number of 

Households 

(Alternative Option)

Community Water Systems (CWSs) not performing Level 1/Level 2 Assessments, or Corrective Actions

Number of 

Households 

(RTCR)

All Community Water Systems (CWSs)

Community Water Systems (CWSs) performing Level 1/Level 2 Assessments (and no Corrective Actions)

Community Water Systems (CWSs) performing Corrective Actions

7% Discount Rate

PWS Size

(Population

Served)

3% Discount Rate

Sources: (C), (E), (G), (I) Exhibit 7.28. 

ES.7 Comparison of Benefits and Costs, and Regulatory Options of the RTCR 

As required by the SDWA, EPA has determined that the benefits of the RTCR justify the 

costs. In making this determination, EPA considered quantified and non-quantified benefits and 

costs as well as the other components of the HRRCA outlined in section 1412 (b)(3)(C) of the 

SDWA. 

Additionally, EPA used several other techniques to compare benefits and costs including 

a break-even analysis and a cost effectiveness analysis. The break-even analysis (see Chapter 9 

of the RTCR EA) was conducted using two example pathogens responsible for some (unknown) 

proportion of waterborne illness in the United States. The analysis shows that a relatively small 

number of cases (based on STEC O157 or Salmonella) would need to be avoided for the rule to 

break-even with the best estimates of net costs. 
Economic Analysis for the Final RTCR ES-23 September 2012

Under the RTCR, approximately two deaths would need to be avoided annually using a 

3% discount rate based on consideration of the bacterial pathogen STEC O157. Alternatively, 

approximately 3,000 or 8,000 non-fatal cases, using the enhanced or traditional benefits 

valuations approaches,5respectively, would need to be avoided to break even with the RTCR 

costs. As expected based on its costs, the Alternative option would require that a higher number 

of cases be avoided annually for that option to break even (between 100% and 113% more than 

the RTCR under the enhanced and traditional approaches, respectively). 

As Exhibit ES.8 shows, approximately 2 deaths would need to be avoided annually from 

a Salmonella infection for the rule to break even. The estimated number of non-fatal Salmonella

cases that would need to be avoided to break even is approximately 10,000 or 68,000 cases under 

the enhanced and traditional benefits valuations approaches, respectively. As expected based on 

its costs, the Alternative option would require that a higher number of Salmonella cases be 

avoided annually for that option to break even (approximately 110% more than the RTCR under 

either the enhanced or traditional approaches). 

As the discussion presented in Chapter 2 of this EA describes, disease and deaths are 

attributable to drinking water contamination across the country. The CDC estimates that there are 

73,000 cases of illness each year in the U.S. due to STEC O157 (Mead et al., 1999). The CDC 

has found that 15% of outbreak cases of STEC O157 are waterborne (Rangel et al., 2005); if that 

rate applies as well to endemic cases, then approximately 11,000 cases would be due to 

waterborne exposure to STEC O157 and could be mitigated. Based on that assumption, up to 

11,000 cases annually may be avoided by measures that mitigate pathways of contamination into 

PWSs for just this one potential contaminant. That amount of reduction in terms of STEC O157 

would be enough for the rule to break even based on either the enhanced or traditional cost of 

illness approaches. If more than one contaminant was reduced or prevented from occurring in 

PWSs, the rule would be that much more likely to break even. Avoided illness and death from 

secondary transmission of infection could also be significant. Additionally, fewer cases would 

need to be avoided if all the benefits of the rule as described in chapter 6 were included in the 

analysis. If increased assessments and corrective actions result in a level of knowledge of the 

system that enables earlier mitigation of potential pathways of contamination, then additional 

illnesses or deaths may be avoided beyond those suggested by the decrease in acute events that 

the model predicts. 

Chapter 9 of the RTCR EA has a complete discussion of the break-even analysis and how 

costs per case were calculated. 

 

5 Both traditional and enhanced COI approaches count the value of the direct medical costs and of time lost that 

would been spent working for a wage, but differ in their assessment of the value of time lost that would be spent in 

nonmarket work (e.g. housework, yardwork, and raising children) and leisure (e.g. recreation, family time, and 

sleep). They also differ in their valuation of (other) disutility, which encompasses a range of factors of well-being, 

including both inconvenience and any pain and suffering. A complete discussion of the traditional and enhanced 

COI approaches can be found in Appendix E. 
Economic Analysis for the Final RTCR ES-24 September 2012

Exhibit ES.7 Estimated Annual Breakeven Threshold for Avoided Cases of STEC 

O157 

Non-fatal

cases only

Fatal 

cases

only1

Non-fatal

cases only

Fatal 

cases

only1

3% 8,000 1.6 17,000 3.4

7% 8,000 1.6 18,000 3.6

3% 3,000 1.6 6,000 3.4

7% 3,000 1.6 6,000 3.6

RTCR

COI

Methodology

Discount 

Rate

Alternative Option

Traditional

COI

Enhanced COI

1 Calculations for fatal cases include the non-fatal COI component for the underlying 

illness prior to death. 

Notes: 

1) The number of cases needed to reach break-even threshold calculated by dividing 

the net change in costs for the RTCR (Exhibit 9.11) by the average estimated value 

of avoided cases (Exhibit 9.18). Threshold estimates based on a weighted average 

of the cost of “all cases” that includes both fatal and non-fatal cases is shown in 

Appendix E. STEC O157 is only an example of a pathogenic endpoint that could 

have been used for this analysis. Use of additional pathogenic contaminants in 

addition to this single endpoint would result in lower threshold values. Detail may 

not add due to independent rounding. 

2) The break-even threshold is higher using a 7% discount rate than a 3% discount 

rate under the Alternative option. This result is consistent with the annualized costs 

of the Alternative option being higher using the 7% discount rate, which is caused 

by the frontloading of costs in the period of analysis, as explained further in Chapter 

7 of the EA. 
Economic Analysis for the Final RTCR ES-25 September 2012

Exhibit ES.8 Estimated Annual Breakeven Threshold for Avoided Cases of 

Salmonella 

Non-fatal

cases only

Fatal 

cases

only1

Non-fatal

cases only

Fatal 

cases

only1

3% 68,000 1.6 141,000 3.4

7% 68,000 1.6 151,000 3.6

3% 10,000 1.6 21,000 3.4

7% 10,000 1.6 23,000 3.6

COI

Methodology

Discount 

Rate

RTCR Alternative Option

Traditional

COI

Enhanced COI

1Note: Calculations for fatal cases include the non-fatal COI component for the 

underlying illness prior to death. 

Notes: 

1) The number of cases needed to reach break-even threshold calculated by dividing 

the net change in costs for the RTCR (Exhibit 9.11) by the average estimated value 

of avoided cases (Exhibit 9.19). Threshold estimates based on a weighted average of 

the cost of “all cases” that includes both fatal and non-fatal cases is shown in 

Appendix E. Salmonella is only an example of a pathogenic endpoint that could have 

been used for this analysis. Use of additional pathogenic contaminants in addition to 

this single endpoint would result in lower threshold values. Detail may not add due to 

independent rounding. 

2) The break-even threshold is higher using a 7% discount rate than a 3% discount rate 

under the Alternative option. This result is consistent with the annualized costs of the 

Alternative option being higher using the 7% discount rate, which is caused by the 

frontloading of costs in the period of analysis, as explained further in Chapter 7 of the 

EA.
Economic Analysis for the Final RTCR ES-26 September 2012

Cost effectiveness is another way of examining the benefits and costs of the rule. ES.9 

shows the cost of the rule per corrective action implemented. The cost effectiveness analysis, as 

with the net benefits, is limited because EPA was able to only partially quantify and monetize the 

benefits of the RTCR. The RTCR achieves the lowest cost per corrective action implemented 

among the options considered. 

Exhibit ES.9 Total Net Annual Cost Per Corrective Action Implemented under the 

RTCR and Alternative Option, Annualized Using 3% and 7% Discount Rates 

($Millions, $2007) 

Regulatory Option 3% Discount Rate 7% Discount Rate

RTCR - Net Change $ 14.3 $ 14.2

RTCR - Incremental Number of Corrective Actions (L1 & L2) 616 594

RTCR - Cost Effectiveness Analysis1 $ 0.02 $ 0.02

Alternative Option - Net Change $ 29.6 $ 31.7

Alternative Option - Incremental Number of Corrective Actions (L1 & L2) 808 819

Alternative Option - Cost Effectiveness Analysis1

$ 0.04 $ 0.04

Notes: 

1CEA = (Net Change)/(Incremental Number of corrective actions). 

2Detailed cost information is provided in Appendix C.

EPA also considered the net cost effectiveness of the RTCR as compared to the 

Alternative option to determine the additional benefit associated with that portion of cost for the 

Alternative option that exceeds the cost of the RTCR. Exhibit ES.9 shows that in terms of net 

rule cost for all PWSs, the RTCR has a far lower unit cost per unit benefit than the Alternative 

option. EPA further considered the group of 60,200 TNCWSs using GW and serving ≤100 

people, which is the largest subset of systems by size and type, and is expected to bear the 

highest burden under the RTCR. Exhibit ES.10 shows that in terms of net rule cost, the cost 

effectiveness of the RTCR far exceeds that of the Alternative option using either a 3% or 7% 

discount rate. The two net cost analyses (ES.9 and ES.10) together indicate that the RTCR is 

significantly more cost effective than the Alternative option for the most burdened subset of 

systems and for all the PWSs together. Additional information about this analysis and other 

methods used to compare benefits and costs can be found in Chapter 9 of the RTCR EA. 
Economic Analysis for the Final RTCR ES-27 September 2012

Exhibit ES.10 Annualized Net Change in Costs Per Corrective Action (CA) 

Implemented for All PWSs under the RTCR and Alternative Option ($Millions, 

2007$) 

Regulatory Option 3% Discount Rate 7% Discount Rate

RTCR - Net Change $ 14.30 $ 14.17

RTCR - Incremental Number of Corrective Actions (L1 & L2)1 615.82 593.71

RTCR - Incremental Cost per Corrective Action ($) $ 0.02 $ 0.02

Alternative Option - Net Change (over RTCR)2 $ 15.29 $ 17.52

Alternative Option - Incremental Number of Corrective Actions (L1 & L2) (over RTCR)2

 192.23 224.93

Alternative Option - Incremental Cost per Corrective Action ($) $ 0.08 $ 0.08

Notes: 

1

Exhibit includes the number of corrective actions predicted by the RTCR occurrence model to be implemented in 

addition to those implemented under the 1989 TCR. 

2

Add net values for Alternative option to net values for RTCR to calculate total net values of Alternative option over 

the 1989 TCR. 

3Detailed cost information is provided in Appendix C.

Exhibit ES.11 Annualized Net Change in Costs per CA Implemented for TNCWSs 

(Serving <100 people) under the RTCR and Alternative Option ($Millions, 2007$) 

Regulatory Option 3% Discount Rate 7% Discount Rate

RTCR - Net Change $ 5.3 $ 5.3

RTCR - Incremental Corrective Actions (L1 & L2)1 287 275

RTCR - Incremental Cost per Corrective Action ($) $ 0.02 $ 0.02

Alternative Option - Net Change (over RTCR)2 $ 9.4 $ 10.8

Alternative Option - Incremental Corrective Actions (L1 & L2) (over RTCR)2

132 155

Alternative Option - Incremental Cost per Corrective Action ($) $ 0.07 $ 0.07

Notes: 

1Derived by dividing incremental rule costs applicable to TNCWS <100 by the incremental number of corrective 

actions to be implemented under the RTCR (relative to the 1989 TCR) and the Alternative option (relative to the 

RTCR) by TNCWSs using GW. 

2

Add net values for Alternative option to net values for the RTCR to calculate total net values of Alternative option 

over the 1989 TCR. 

3Detailed cost information is provided in Appendix C.

ES.8 Conclusion 

The RTCR aims to further reduce occurrence of TC and E. coli (and any waterborne 

pathogens that may co-occur) beyond the reductions achieved under the 1989 TCR. EPA’s goal 

is to increase public health protection from potential fecal contamination and/or waterborne 

pathogen exposure, while continuing to pursue the objectives of the 1989 TCR. Although EPA's 

analysis of the RTCR has determined that its annual costs are most likely below the threshold 

stated in Executive Order 12866 of $100 million, EPA has chosen to publish a complete EA for 

this rule. 

EPA has developed the final RTCR to be consistent with the majority of the AIP 

recommendations, with consideration of the comments received on the proposed rule, because it 

will not allow for backsliding from current levels of protection of public health and will likely 
Economic Analysis for the Final RTCR ES-28 September 2012

reduce risk from waterborne disease further while costing relatively little on a net basis. This 

conclusion is consistent with the conclusion of the TCRDSAC regarding the likely impact of the 

rule provisions. As required by the SDWA, EPA has determined that the benefits of the RTCR 

justify the costs. In making this determination, EPA considered quantified and non-quantified 

benefits and costs as well as the other components of the HRRCA outlined in section 1412 

(b)(3)(C) of the SDWA. 

As shown in the uncertainty analysis presented in Chapter 6 (section 6.4), reducing repeat 

samples and additional samples both have the potential to increase risk for some PWSs (see also 

sections III.C and III.D of the RTCR preamble for discussions on the additional routine sample 

and repeat sample provisions respectively). However, this increase in risk is expected to be more 

than offset by potential decreases in risk from increased routine monitoring and the addition of 

the assessments and corrective action provisions that find and fix problems indicated by 

monitoring. That is, based on the analyses presented in this EA, EPA concludes that the effect of 

the corrective actions outweighs that of reduced sampling; both the RTCR and the Alternative 

option are expected to result in a net decrease in risk as compared to the 1989 TCR. Although the 

Alternative option decreases risk to a greater degree than the RTCR, this additional reduction is 

achieved at a higher cost, both in absolute terms and in terms of cost-effectiveness. The 

estimated net cost of the RTCR is not only small relative to the 1989 TCR (approximately $14 

million annually using either a 3% or 7% discount rate), but it is also small compared to net cost 

increase of the Alternative option relative to the 1989 TCR (approximately $30–$32 million 

using a 3% and 7% discount rate, respectively). This cost differential is especially important 

considering the potential concentration of impacts on the smallest TNCWSs and the potential 

frontloading of costs during the first few years of implementation under the Alternative option. 

In addition, no backsliding in overall risk is predicted. 

The analyses performed as part of this EA support the collective judgment and consensus 

of the TCRDSAC that the RTCR requirements provide for effective and efficient revisions to 

1989 TCR regulatory requirements. 
Economic Analysis for the Final RTCR 1-1 September 2012

1 Introduction 

This economic analysis (EA) presents the evaluation of the benefits and costs of the 

Revised Total Coliform Rule (RTCR). The analysis is performed in compliance with Executive 

Order 12866, Regulatory Planning and Review (58 FR 51735), which requires the United States 

Environmental Protection Agency (EPA) to estimate the economic impact of rules that have an 

annual effect on the economy of over $100 million and make that analysis available to the public 

in conjunction with publication of the final rule. Although EPA's analysis of the RTCR has 

determined that its annual costs are most likely below this threshold, EPA has chosen to publish 

a complete EA for this rule.

EPA developed the RTCR in collaboration with states, other interested stakeholders, and 

the Total Coliform Rule/Distribution System Advisory Committee (TCRDSAC). In July 2003, as 

part of the Agency’s Six Year Review of existing national primary drinking water regulations, 

EPA published its intent to revise the 1989 Total Coliform Rule (TCR). The Agency’s primary 

reasons for revising the 1989 TCR are implementation-related issues. The RTCR offers a 

meaningful opportunity for greater public health protection against waterborne pathogens in the 

distribution systems of public water systems (PWSs) beyond the 1989 TCR. 

This chapter provides a summary of the RTCR in Section 1.1. Section 1.2 outlines the 

organization of this EA, and Section 1.3 provides information regarding supporting calculations 

and citations. 

1.1 Summary of the Revised Total Coliform Rule (RTCR) 

The RTCR applies to all community and noncommunity PWSs. The RTCR takes a 

proactive approach to protect public health, maintaining a maximum contaminant level goal 

(MCLG) and maximum contaminant level (MCL) for E. coli and using both E. coli and total 

coliform (TC) monitoring to establish a framework for PWSs to assess for sanitary defects and to 

correct them as appropriate. 

Like the requirements of the 1989 TCR, the requirements of the RTCR ensure that PWSs 

address the following objectives: 

 Evaluate the effectiveness of treatment; 

 Determine the integrity of the distribution system; and 

 Signal the possible presence of fecal contamination. 

To accomplish the above objectives, the RTCR uses TC as an indicator to start an 

evaluation process that, where necessary, requires the PWS to correct sanitary defects, defined in 

the RTCR as: 

A defect that could provide a pathway of entry for microbial contamination into the 

distribution system or that is indicative of a failure or imminent failure in a barrier that is 

already in place. 
Economic Analysis for the Final RTCR 1-2 September 2012

Under the RTCR, E. coli remains a regulated contaminant with an MCLG of zero and an 

MCL of zero. All fecal coliform provisions (including the MCLG and MCL) are removed in the 

RTCR. There is no longer an MCL for TC: instead, TC is used as an indicator as part of a 

coliform treatment technique. 

For all PWSs serving >4,100 people, monitoring requirements under the RTCR remain 

essentially unchanged from 1989 TCR requirements. However, PWSs serving ≤4,100 people 

may experience changes in their required monitoring schemes depending on specific size, type, 

and source water categorizations. Changes for these PWSs may be for routine, additional routine 

or repeat monitoring as summarized in Exhibit 1.1 below. 

Under the RTCR, PWSs must complete Level 1 or Level 2 assessments to identify the 

presence of “sanitary defects” and defects in distribution system coliform monitoring practices if 

sampling results in one of the following triggers listed below. 

Level 1 Assessment Triggers 

 For PWSs taking 40 or more samples per month, the PWS exceeds 5.0 percent TCpositive samples for the month; or 

 For PWSs taking fewer than 40 samples per month, the PWS has two or more TCpositive samples in the same month; or 

 Failure to take every required repeat sample after a single routine TC-positive 

sample. 

Level 2 Assessment Triggers 

 The PWS has an E. coli violation (See Section III.B.1.a of the RTCR preamble for a 

description of what constitutes an E. coli MCL violation.); or

 The PWS has a second Level 1 treatment trigger within a rolling 12-month period, 

unless the first Level 1 treatment trigger was based on exceeding the allowable 

number of TC+ samples, the state has determined a likely reason for the TC+ 

samples that caused the initial Level 1 treatment trigger, and the state establishes 

that the system has fully corrected the problem; 

 For PWSs with approved reduced annual monitoring, a Level 1 treatment technique 

trigger in two consecutive years. 
Economic Analysis for the Final RTCR 1-3 September 2012

Exhibit 1.1 RTCR Monitoring Frequency Requirements 

PWS Type Source Population Served Monitoring Requirements 

Routine Monitoring1

Noncommunity 

(NCWS)

Ground water ≤ 1,000 people Quarterly monitoring for TC2 

Additional requirements to qualify for reduced 

3 monitoring apply 

Community 

(CWS)

Ground water ≤ 1,000 people Monthly monitoring for TC

Additional requirements to qualify for reduced 

4 monitoring apply 

All

(CWS & NCWS)

Surface water All Same requirements as under 1989 TCR

(Monthly monitoring for TC)

Ground water >1,000 people Same requirements as under 1989 TCR

(Monthly monitoring for TC)

Additional Routine Monitoring

All

(CWS & NCWS)

Ground water ≤ 1,000 people Additional routine monitoring no longer 

required if monitoring monthly

Number of additional routine samples required 

reduced from five to three if monitoring 

quarterly or annually

Ground water 1,101–4,100 people Additional routine monitoring no longer 

required

Surface water ≤4,100 people Additional routine monitoring no longer 

required

Ground and 

surface water

>4,100 people Same requirements as under 1989 TCR

(Additional routine monitoring not required)

Repeat Monitoring

All

(CWS & NCWS)

Ground and 

surface water

≤1,000 people Number of repeat samples required reduced 

from four to three

Ground and 

surface water

>1,000 people Same requirements as under 1989 TCR

(Three repeat samples required)

1

Seasonal PWSs serving ≤ 1,000 people are required to sample monthly while in service but may qualify for reduced 

monitoring. 

2

 PWSs may be increased to monthly monitoring based on compliance with rule. Examples include system with Level 

2 assessment violation, an E. coli MCL violation, an RTCR treatment technique violation, and /or two monitoring 

violations in a rolling 12-month period. 

3 PWSs may qualify for annual monitoring based on compliance record, the existence of enhancements to water 

system barriers to contamination, and completion of an initial and recurring annual site visit conducted by the state or 

an annual voluntary Level 2 assessment by a party approved by the state. 

4 PWSs may qualify for quarterly monitoring based on compliance record and either the existence of enhancements 

to water system barriers to contamination or the completion of an annual site visit conducted by the state or an 

annual voluntary Level 2 assessment by a party approved by the state.
Economic Analysis for the Final RTCR 1-4 September 2012

The PWS shall be responsible for correcting sanitary defects found through either Level 1 

or Level 2 assessments as defined above by implementing appropriate corrective actions. Failure 

to complete a required assessment or take necessary corrective action constitutes a Treatment 

Technique violation under the RTCR. 

The RTCR requires public notification for three events that are tiered as follows: 

 Tier 1. E. coli MCL violation 

 Tier 2. Treatment technique violation 

 Tier 3. Routine monitoring and reporting violations 

The RTCR also provides the primacy agency with the discretion to reduce the monitoring 

frequency for well-operated ground water PWSs serving ≤1,000 people, if the PWS can 

demonstrate that it meets the criteria for reduced monitoring stipulated in the rule. The specific 

criteria to qualify for reduced monitoring are described in Chapter 3. 

Ground Water Rule (GWR) implementation began in December of 2009 prior to the 

transition from the 1989 TCR to the RTCR. Compliance with the GWR requirements, including 

sanitary surveys and site visits, can be used to help determine the level of monitoring required 

for ground water PWSs serving ≤1,000 people. 

1.2 Document Organization 

The remainder of this EA is organized into the following chapters: 

 Chapter 2 summarizes the technical, regulatory, and public health issues addressed 

by the RTCR. It also explains the statutory authority for the RTCR and the 

economic rationale for the regulatory approach. 

 Chapter 3 reviews various regulatory options that EPA considered during the 

development of the rule and presents the rationale for selecting the RTCR 

requirements. 

 Chapter 4 characterizes baseline conditions that exist (including PWS inventory, 

treatment, and water quality data) before PWSs make changes to meet the RTCR 

requirements. 

 Chapter 5 summarizes TC and EC occurrence analysis, providing a description of 

the occurrence model, the sources used, and the limitations or constraints to the 

analysis based on the nature of the data provided by those sources. 

 Chapter 6 presents the relative risk evaluation performed to estimate the potential 

benefits of the RTCR relative to the baseline and other regulatory options 

considered. 
Economic Analysis for the Final RTCR 1-5 September 2012

 Chapter 7 presents an estimate of the net costs of implementing the RTCR to 

industry, households, and states. The net costs of all regulatory options considered 

are compared. 

 Chapter 8 discusses distributional analyses performed to evaluate the effects of the 

rule on different segments of the population, and considers various executive orders 

and requirements, including the Regulatory Flexibility Act and Unfunded Mandates 

Reform Act. 

 Chapter 9 compares the benefits and costs of the RTCR to evaluate the potential 

net benefits and cost-effectiveness. The results are discussed and compared to other 

regulatory options considered.

 Chapter 10 includes a detailed list of references.

1.3 Calculations and Citations 

This EA involves detailed and complex analyses, and the following are provided to help 

the reader: 

 The detailed reference section provided in Chapter 10. 

 Appendices containing supporting spreadsheets and analyses: 

– Appendix A—Detailed Predictive Model Results 

– Appendix B—Graphs of Predicted Hit Rates Over Time

– Appendix C—Detailed Cost Model Results

– Appendix D—Detailed Compliance Forecast and Unit Costs Estimates 

– Appendix E—Supporting information for Value of Statistical Life and 

Cost of Illness estimates used in break-even analyses 

– Appendix F—Detailed analysis of potential uncertainty and variability in 

occurrence estimates 

– Appendix G—Evaluation of representativeness of Six Year Review data 

– Appendix H—Analysis of potential impacts of reduced repeat sampling 

– Appendix I—Supporting Information for Regulatory Flexibility Act 

Screening Analysis 

 Exhibits. Most tabular exhibits include a row that provides the formulas used to 

compute the contents of each column. 

 Sources for values used if they were not calculated within the exhibits. 
Economic Analysis for the Final RTCR 1-6 September 2012

 Supporting electronic file outputs (i.e., RTCR occurrence and cost model output). 

 Flowcharts that illustrate methodologies of analyses as well as RTCR requirements.
Economic Analysis for the Final RTCR 2-1 September 2012

2 Statement of Need for the Rule 

2.1 Introduction 

The United States Environmental Protection Agency (EPA) is revising the 1989 Total 

Coliform Rule (TCR) to better protect public health. EPA noticed its intent to revise the 1989 

TCR as part of its Six-Year Review determination published in 2003 (USEPA 2003b, 68 FR 

42907, July 18, 2003). In July 2007 EPA convened a Total Coliform Rule/Distribution System 

Federal Advisory Committee (TCRDSAC or advisory committee) charged with evaluating how 

well the objectives of the TCR are met and recommending possible revisions to the rule. The 

TCRDSAC completed its analysis and provided recommendations for revising the 1989 TCR in 

an Agreement in Principle (AIP) (USEPA, 2009, 74 FR 1683, January 13, 2009) that was signed 

by advisory committee members in September 2008. In July 2010, EPA proposed a rule that was 

consistent with the recommendations in the AIP (see Chapter 3 of this economic analysis (EA) 

for more details on the TCRDSAC). The final RTCR provisions were created by also taking into 

consideration comments received on the RTCR proposal. 

The RTCR maintains and strengthens the objectives of the 1989 TCR. The objectives are: 

(1) to evaluate the effectiveness of treatment, (2) to determine the integrity of the distribution 

system, and (3) to signal the possible presence of fecal contamination. The RTCR better 

addresses these objectives by requiring systems that may be vulnerable to fecal contamination 

(as indicated by their monitoring results) to do an assessment, to identify whether any sanitary 

defect(s) is (are) present, and to correct the defects. Therefore, greater public health protection is 

anticipated under the RTCR compared to the 1989 TCR because of its more preventive approach 

to identifying and fixing problems that affect or may affect public health (see Chapter 3 of this 

EA for more details on the provisions of the RTCR). 

This chapter summarizes the technical, regulatory, and public health issues addressed by 

the final rule. It also explains the statutory authority for the final RTCR and the economic 

rationale for choosing a regulatory approach rather than non-regulatory options. 

2.1.1 Description of the Issue 

EPA is required to review each existing national primary drinking water regulation 

(NPDWR) every six years. In 2003, EPA completed its review of the 1989 TCR and 68 

NPDWRs for chemicals that were established prior to 1997. The purpose of the review was to 

identify current health risk assessments, changes in technology, and other factors that would 

provide a health or technological basis to support a regulatory revision that will maintain or 

improve public health protection. In the 2003 announcement of the completion of the Six Year 

Review, EPA provided public notice of its intent to revise the 1989 TCR (USEPA 2003b, 68 FR 

42907, July 18, 2003). Implementation-related issues are the primary reason for EPA’s decision 

to revise the 1989 TCR. Since promulgation of the 1989 TCR, EPA has received comments from 

a number of stakeholders suggesting modifications to reduce the burden of implementing the 

1989 TCR. These comments included, among others, suggestions to modify the 1989 TCR’s 

monitoring requirements (e.g., with regards to sampling locations and repeat samples) (USEPA 

2002b, 67 FR 19030, April 17, 2002 and USEPA 2003b, 68 FR 42907, July 18, 2003). 
Economic Analysis for the Final RTCR 2-2 September 2012

The 1989 TCR was promulgated to decrease the risk of waterborne illness. Among all 

rules promulgated for preventing waterborne illness, only the 1989 TCR applies to all PWSs, so 

the rule is an essential component of the multiple barrier approach in public health protection 

against endemic and epidemic disease. However, improvements to the 1989 TCR construct and 

requirements can better protect public health as shown in the following discussions. 

In recent years, violation rates under the 1989 TCR have remained relatively steady (see 

Chapter 4, Exhibit 4.11 of this EA). EPA believes that this is reflective of a steady state among 

PWSs complying with the 1989 TCR, suggesting the possibility that improvements likely to 

occur under the 1989 TCR have largely been achieved. Potential exposure to waterborne 

pathogens continues to be a health risk. Within the United States, disease is caused by a 

relatively small variety of bacterial, viral, and parasitic protozoan pathogens in drinking water. 

Nevertheless, the number of potential waterborne pathogens and the number of potential 

waterborne illnesses are significant. Humans can be exposed via fecal-oral, inhalation or dermal 

exposure, with fecal-oral exposure being the most significant and prevalent pathway. 

The 1989 TCR established a maximum contaminant level goal (MCLG) and a maximum 

contaminant level (MCL) for total coliforms (TC) (including fecal coliforms (FC) and E. coli).

Under the 1989 TCR, a TC MCL violation required public notification. However, many of the 

organisms detected by TC and FC methods are not of fecal origin and do not have any direct 

public health implication. Information has also become available since promulgation of the 1989 

TCR that indicates that measurement of FC sometimes detects organisms that may not have any 

connection to fecal contamination (Edberg et al., 2000). Attributing greater public health 

significance to the presence of TC or FC could result in public confusion. On the other hand, 

EPA continues to believe that E. coli is a meaningful indicator of fecal contamination and of the 

potential presence of associated pathogens (see Section 2.2.4.1 of this chapter). 

The RTCR aims to maintain and strengthen the objectives of the 1989 TCR more 

effectively and efficiently. E. coli remains a regulated contaminant with a defined MCLG and 

MCL while TC (including FC) no longer has an MCLG and an MCL. Instead, the final RTCR 

uses TC as an indicator as part of a coliform treatment technique. The treatment technique uses 

both TC and E. coli monitoring results to start an evaluation process that, where necessary, will 

require the PWS to conduct assessments and corrective actions. The final rule also takes into 

account the capacity of small systems (especially for PWSs serving 1,000 or fewer people) and 

primacy agencies to effectively implement the final rule requirements. 

Modeling results show that the assessment and corrective action provisions of the RTCR 

will result in a decrease in E. coli occurrence (see Exhibits 5.16–5.21) which is anticipated to 

lead to a decrease in the potential exposure of the public to fecal contamination and its associated 

pathogens. In general, this decrease in fecal contamination should reduce the potential risk to 

human health of PWS customers. Thus, any reduction in E. coli occurrence is considered a 

benefit of the RTCR. Also, since fecal contamination can contain waterborne pathogens 

including bacteria, viruses, and parasitic protozoa, in general a reduction in fecal contamination 

should also reduce the potential risk from these other contaminants. 
Economic Analysis for the Final RTCR 2-3 September 2012

2.2 Public Health Concerns, Fecal Contamination, and Waterborne Pathogens 

2.2.1 Rule Objectives and Public Health Concerns 

The RTCR aims to increase public health protection through a reduction of potential 

pathways of entry for fecal contamination into the distribution system. Since these potential 

pathways represent vulnerabilities in the distribution system whereby fecal contamination and/or 

waterborne pathogens, including bacteria, viruses, and parasitic protozoa can enter the system, 

the reduction of these pathways in general should lead to reduced exposure and associated risk 

from these contaminants. Waterborne pathogens that can be associated with fecal contamination 

may cause a variety of illnesses, including acute gastrointestinal illness (AGI) with diarrhea, 

abdominal discomfort, nausea, vomiting, and other symptoms. Most AGI cases are of short 

duration and result in mild illness. Consuming water contaminated with waterborne pathogens 

can also result in acute illnesses such as hepatitis, hemolytic uremic syndrome (kidney failure), 

and bloody diarrhea; milder, acute illnesses such as conjunctivitis; and severe chronic illnesses 

such as diabetes and dilated cardiomyopathy. Other examples of potential chronic diseases 

resulting from infection by a waterborne agent include irritable bowel syndrome, hypertension, 

and reactive arthritis; chronic illnesses are generally costly to treat.6

Sensitive subpopulations are at greater risk from waterborne disease than the general 

population. These sensitive subpopulations include children (especially the very young); the 

elderly; the malnourished; pregnant women; chronically ill patients (e.g., those with diabetes or 

cystic fibrosis); and a broad category of those with compromised immune systems, such as 

Acquired Immunodeficiency Syndrome (AIDS) patients, those with autoimmune disorders (e.g., 

rheumatoid arthritis, lupus erythematosus, and multiple sclerosis), organ transplant recipients, 

and those receiving chemotherapy (Rose, 1997). Sensitive subpopulations represent almost 20 

percent of the population in the United States (Gerba et al., 1996). The severity and duration of 

illness is often greater in sensitive subpopulations than in healthy individuals, and may 

occasionally result in death. 

When humans are exposed to and infected by an enteric pathogen (pathogens that most 

commonly occur in the gut of humans and other animals), the pathogen becomes capable of 

reproducing in the gastrointestinal tract. As a result, healthy humans shed pathogens in their 

feces for a period ranging from days to weeks. This shedding of pathogens often occurs in the 

absence of any signs of clinical illness. Regardless of whether a pathogen causes clinical illness 

in the person who sheds it in his or her feces, the pathogen being shed may infect other people 

directly by person-to-person spread, contact with contaminated surfaces, and other means which 

are referred to as secondary spread. As a result, waterborne pathogens that are initially 

waterborne may subsequently infect other people through a variety of routes (WHO, 2004). 

Waterborne pathogens include pathogens of both fecal and non-fecal origin. Non-fecal 

pathogens are found in the soil and soil water interface and include Legionella, Naegleria fowleri

 

6

 Lifetime costs associated with a new case of diabetes, for example, assuming an average illness duration of 30 

years, are estimated at $255,833 using a three percent discount rate and $161,967 using a seven percent discount rate 

(year 2007 dollars). For dilated cardiomyopathy, the lifetime (21-year average) cost is $68,870 (seven percent 

discount rate, year 2007 dollars). 
Economic Analysis for the Final RTCR 2-4 September 2012

and probably Helicobacter pylori, or are components of the distribution system environment and 

can include Mycobacterium avium complex (MAC). Examples of common fecal bacterial 

pathogens include pathogenic E. coli, Salmonella, Shigella, and Campylobacter jejuni. Some 

waterborne bacterial pathogens cause disease by rapid growth and dissemination (e.g., 

Salmonella) while others primarily cause disease via toxin production (e.g., Shigella, E. coli 

O157, Campylobacter jejuni). Campylobacter jejuni, E. coli, and Salmonella have a host range 

that includes both animals and humans; Shigella is associated only with humans (Geldreich, 

1996). Unlike viruses, bacteria are able to reproduce outside of the host. 

Because a positive TC assay is an indicator of ambient water entry into or growth within 

the distribution system, it represents an indication of potential for both fecal and non-fecal 

contamination. Because E. coli originates in the gut of warm-blooded animals, it is an indication 

of fecal contamination. Together, the TC/E. coli indicator system can be used in monitoring to 

identify the potential for fecal contamination. Since fecal contamination can contain waterborne 

pathogens including bacteria, viruses, and parasitic protozoa, in general a reduction in fecal 

contamination should also reduce the potential risk from these other contaminants. 

The group of bacteria known as E. coli contains both pathogenic and non-pathogenic 

isolates. The methods approved by EPA to assay for E. coli do not identify most of the 

pathogenic E. coli strains. The most dangerous E. coli bacteria contain the gene for producing 

shiga-toxins. E. coli O157:H7 is the most widespread shiga-toxin producing E. coli but at least 

81 serotypes have been identified (Prager et al., 2005). Release of toxins in the body can result in 

kidney failure, shock and death in otherwise healthy individuals, especially small children. 

Typically, kidney failure occurs in 2–7 percent of illnesses. Death or end-stage renal disease 

occurs in about 12 percent of patients four years after diarrhea-associated kidney failure (Garg et 

al., 2003). Twenty five percent of kidney failure survivors demonstrate long-term renal 

consequences (Garg et al., 2003). For patients with moderate and severe gastroenteritis caused by 

E. coli, long-term study shows that they have an increased risk of irritable bowel syndrome, 

hypertension and reduced kidney function (Garg et al., 2005). 

The Centers for Disease Control and Prevention (CDC) indicates that drinking water is 

responsible for a portion of the 73,000 illnesses each year from E. coli O157:H7 (Mead et al., 

1999). The CDC estimates that about 15 percent of all reported E. coli O157:H7 cases are due to 

water contamination (Rangel et al., 2005). E. coli O157:H7 is the primary cause of hemolytic 

uremic syndrome (HUS) in the United States (Rangel et al., 2005). Active surveillance by CDC 

shows that 6.3 percent of E. coli O157:H7 cases progress to HUS (Griffin and Tauxe, 1991; 

Gould et al., 2009) and about 12 percent of HUS cases result in death within four years (Garg et 

al., 2003). About 4 to 15 percent of STEC O157 cases are transmitted within households by 

secondary transmission (Parry and Salmon, 1998).

Ground water outbreaks due to E. coli O157:H7 are prominent because of the fatal 

outcomes associated with those outbreaks. In Walkerton, Ontario, 6 individuals died and 27 

developed kidney failure from ground water contaminated with E. coli O157:H7 (and 

Campylobacter jejuni) (Health Canada, 2000). The outbreak coincided with a reduction in 

chlorination treatment coincident with a large fecal contamination event. In Washington County, 

NY, two individuals (including an otherwise healthy two year old child) died from E. coli 

O157:H7 contamination of a county fair water supply system. (The fairground’s water supply 
Economic Analysis for the Final RTCR 2-5 September 2012

system was not recognized as a PWS because it was used for less than 60 days each year.) Four 

individuals died in Cabool, MO due to E. coli O157:H7 (Swerdlow et al., 1992) in an outbreak 

that was likely due to source water contamination. 

Although manure is often considered to be the source of shiga-toxin producing E. coli, 

these bacteria have also been isolated from municipal sewage (Holler et al., 1999). E. coli 

O157:H7 was found to survive on a pasture surface for almost 4 months. About 4–15 percent of 

cases are acquired via secondary transmission (Parry and Salmon, 1998). In addition to the shigatoxin producing E. coli, there are a substantial number of other E. coli bacteria that are 

pathogenic, mostly through production of other toxins. Little data are available on the hazard 

associated with waterborne transmission for most of the pathogenic E. coli other than E. coli 

O157:H7. 

As the result of a seven-year-long study of individuals infected or ill during the 

Walkerton, Ontario waterborne disease outbreak due to E. coli O157:H7 and Campylobacter 

jejuni, researchers noted an increased incidence in chronic disease sequellae. Within a few years 

after the outbreak, irritable bowel syndrome, hypertension, reactive arthritis and reduced kidney 

function increased 33–38 percent (Clark et al., 2008). 

Shigella bacteria are distinct because they are often associated with bloody diarrhea 

(bacillary dysentery). The enterohemorraghic E. coli bacteria acquired the capability to produce 

toxins by exchanging plasmids with Shigella (Murray et al., 2007). Thus, Shigella often also 

causes kidney failure and chronic kidney disease. Shigella contamination only results from 

human fecal contamination and thus it is probably less common than E. coli contamination, 

which has both human and animal sources. 

Campylobacter bacteria (like Salmonella) are very common contaminants of food and 

water, and result in a large number of illnesses. Campylobacter is commonly associated with 

animal manure, especially cow and chicken manure. More deaths may be associated with 

Campylobacter and Salmonella than with viruses. Uniquely, Campylobacter is often associated 

with Guillain-Barre paralysis that can last for weeks or months. About one paralysis case occurs 

for every 1,000 cases of campylobacteriosis (Altekruse et al., 1999). About 20 percent of 

paralysis patients are left with some disability and approximately 5 percent die. 

Campylobacterosis is also associated with Reiter syndrome (reactive arthritis). Approximately 1 

percent of patients with camplybacterosis have arthritis onset in one or more joints (especially 

the knee) in the 7 to 10 days after diarrheal onset (Altekruse et al., 1999). Arcobacter (now a 

separate genus from Campylobacter) was responsible for a ground water outbreak at a camp in 

Coeur d'Alene, Idaho (McMillan, 1996). 

Salmonella causes typhoid fever, once a common and dangerous waterborne disease. 

Typhoid is no longer a problem in the United States, and in recent years, Salmonella has become 

increasingly less common as a common source outbreak agent while campylobacterosis

outbreaks have correspondingly increased. The reasons for this change are unclear. Seven deaths 

that occurred due to Salmonella contamination in a ground water PWS in Gideon, Missouri were 

due to bird entry into a storage tank (Angulo et al., 1997). Salmonella resulted in a very large 

outbreak in a ground water utility in Riverside, California during the 1960s (16,000 illnesses, 70 

hospitalizations and 3 deaths) prior to the promulgation of the 1989 TCR (Boring et al., 1971). A 
Economic Analysis for the Final RTCR 2-6 September 2012

2008 waterborne outbreak in Alamosa, Colorado was due to Salmonella. Salmonella-positive 

samples were collected from the distribution system but no E. coli was identified in other 

distribution samples collected on the same day (CDPHE, 2009). 

Legionella are opportunistic bacterial pathogens that colonize water distributions 

systems. An estimated 8,000–18,000 cases of Legionnaires disease and Pontiac fever occur in the 

U.S. each year due to Legionella (CDC, 2011). Twenty-one of 48 known species are able to 

infect humans. 

Helicobacter pylori is often associated with ground water (Hegarty et al.,1999; RolleKampzczyk et al., 2004) and is known to cause gastric ulcers. However, Helicobacter is not 

culturable and so occurrence data are fairly uncertain. Improved hygiene and water treatment 

have together reduced the number of ulcers caused by this organism over the last few decades 

but it is impossible to quantify that decrease. 

Most of the waterborne bacterial pathogens cause gastrointestinal illness, but some can 

cause other severe illnesses as well. For example, Legionella causes Legionnaires Disease, a 

form of pneumonia that has a fatality rate of about 15 percent. It can also cause Pontiac Fever, 

which is a milder respiratory infection form of Legionnaires Disease. Several strains of E. coli 

can cause severe disease, including kidney failure. Some bacterial pathogens are opportunistic 

(i.e., they are only infectious in the presence of another, preexisting condition or weakness). 

Opportunistic pathogens usually cause illness only in immunocompromised persons or in other 

sensitive subpopulations, such as the very young or the elderly. Other pathogens, such as 

Salmonella, Shigella, and Campylobacter jejuni, are not entirely opportunistic but result in 

certain diseases with greater frequency and severity in immunocompromised persons (Framm 

and Soave, 1997). 

Examples of common viral pathogens include norovirus and the enteroviruses 

(coxsackievirus, echovirus, poliovirus, enterovirus 70 and 71). Viruses can cause a spectrum of 

mild to severe clinical illness, including paralytic disease and death. There is considerable 

information that Type 1 diabetes may be associated with enterovirus infection, including 

infection with coxsackievirus and echoviruses (Maria et al., 2005; Vreugdenhil et al., 2000). 

Dilated cardiomyopathy can follow myocarditis caused by echovirus and other enterovirus 

infection. 

Mild enteroviral illness includes nonspecific febrile illness, respiratory illness, 

photophobia or sensitivity, stiff neck, and gastrointestinal illness. Aseptic meningitis may or may 

not require a doctor’s visit, but more severe illnesses such as viral encephalitis, myocarditis, and 

non-polio flaccid paralysis are likely to require hospitalization. Most likely to be hospitalized are 

infants less than 3 months old with non-specific febrile illnesses that require treatment to rule out 

and expectantly treat serious bacterial illness. Dilated cardiomyopathy can follow myocarditis 

caused by echovirus and other enterovirus infection. 

The health effects of norovirus illness include acute onset of nausea, vomiting, abdominal 

cramps and diarrhea. Vomiting is more prevalent among children. However, many adults also 

experience vomiting, as well as diarrhea. Constitutional symptoms (e.g., headache, fever, chills, 

and myalgia) are frequently reported. Although rare, severe dehydration caused by norovirus 
Economic Analysis for the Final RTCR 2-7 September 2012

gastroenteritis can be fatal, with this outcome occurring among susceptible persons (e.g., older 

persons with debilitating health conditions). No long-term sequelae of norovirus infection have 

been reported (CDC, 2001a). Duration of illness is typically 12–60 hours.

Hepatitis A (HAV) virus is the only waterborne virus that is reportable to CDC. About 

28,000 HAV cases are reported to CDC each year; however, that number is expected to decline 

with time because children are currently vaccinated for HAV in high risk states, and newer 

recommendations are for increased vaccination coverage. Mead et al. (1999) estimate about 

83,000 HAV cases each year (nearly three times the number of cases reported yearly to CDC), 

with a hospitalization rate of 13 percent and a mortality rate of 0.3 percent. Because HAV is 

more severe as an adult disease, an aging U.S. population may have greater disease burden. 

Hepatitis E (HEV) virus is another fecal oral virus that is potentially waterborne. 

Serology and case histories of individual patients indicate that HEV is established as endemic 

within the United States (Tsang et al., 2000). However, the data suggest that only one or a few 

percent of the population has been infected. Unlike HAV, no waterborne outbreaks of HEV have 

occurred in the United Sates, although they have occurred in China and Somalia. The disease is 

severe, with up to 20 percent mortality among pregnant women in developing countries. 

The adenoviruses are a large group of viruses that produce diverse symptoms. Two 

adenovirus serotypes, adenovirus 40 and 41, produce primarily enteric symptoms, but several 

other adenoviruses are also capable of producing such symptoms. Additionally, some 

adenoviruses cause conjunctivitis. Most significantly, adenoviruses caused a fatal outcome in 

otherwise healthy young males in military settings (CDC, 2001b). All adenoviruses, no matter 

the infection site and characteristic illness, are shed copiously through the gut. Thus, the 

adenoviruses are fecal-oral viruses (Carter, 2005) potentially transmissible via water to infection 

sites in the gut or, for the respiratory adenoviruses, in the lung, via waterborne aerosol drops. 

Most children are exposed to astroviruses at an early age. Astrovirus is commonly 

acquired in child care settings and causes mild disease in children. However, a small percentage 

of exposed children may suffer more significant health effects and may require in-patient care. 

The disease burden in older children and adult populations is underestimated because the disease 

is mild (Carter, 2005). Astroviruses are shed in stool in large numbers. In France, prospective 

epidemiology studies have implicated water as a route of astrovirus infection (Gofti-Laroche, et 

al., 2003). 

The CDC has determined that the incidence of rotavirus diarrhea can reach 0.30 

episodes/child/year by age two, with a cumulative incidence approaching 0.80 episodes/child by 

age five (Glass et al., 1996). Hospitalizations for rotavirus diarrhea are most common in children 

6 months to 3 years of age (Parashar et al., 1998), while self-limiting norovirus infections are 

prevalent in school-age children (LeBaron et al., 1990). Although deaths from infectious diarrhea 

have generally declined among U.S. children since 1965 because of re-hydration therapy, 

newborn children, especially infants born prematurely, remain at risk of death from severe 

diarrheal illness (Kilgore et al., 1995). Common strain rotaviruses typically affect young 

children, particularly those less than 3 years old, but other strains (G1, G2 and G9) have been 

found to be common in adults and the elderly in nursing homes, and found to be responsible for 

more severe illness in children (Griffin et al., 2000). In 2006, the U.S. Food and Drug 
Economic Analysis for the Final RTCR 2-8 September 2012

Administration (FDA) approved a new pentavalent vaccine for rotavirus (Vesikari et al., 2006) in 

children. The vaccine protects against the most common rotaviruses now found in the U.S. 

(serotypes G1, G2, G3, G4, and G9) but does not protect against all rotaviruses. 

Reovirus is commonly found co-occurring with the enteroviruses in PWS wells. Carducci 

et al. (2002) found that in some cases enterovirus detection was limited because reovirus 

reproduction was so highly favored. Reovirus is more closely related to rotavirus and thus has 

some similar characteristics. Reovirus is now recognized as a human pathogen in children (Tyler 

et al., 2004). 

Cryptosporidium is of particular concern to EPA because, unlike pathogens such as 

viruses and bacteria, Cryptosporidium oocysts are resistant to inactivation by many common 

disinfection methods. Since the oocysts are especially resistant to chlorine disinfection, simply 

increasing existing chlorination dosage levels or contact time above those most commonly 

practiced in the United States is not effective. Emerging disinfectant-resistant pathogens, such as 

Microsporidia, Cyclospora, and Toxoplasma, are also a concern for similar reasons. 

Cryptosporidiosis is a protozoal infection that usually causes 7 to14 days of diarrhea, 

possibly accompanied by low-grade fever, nausea, and abdominal cramps in individuals with 

healthy immune systems (Juranek, 1998). It is caused by the ingestion of infectious 

Cryptosporidium oocysts, which are readily carried in water. The most common source of 

oocysts in water is the feces of infected hosts (Perz et al.,1998; Rose, 1997). Although 

cryptosporidiosis often occurs through ingestion of contaminated food or water, it may also 

result from direct or indirect contact with infected people or animals (Casemore, 1990; Juranek, 

1998; Rose, 1997). Infected humans and other animals excrete oocysts, which can then be 

transmitted to others. Cryptosporidiosis can also cause non-gastrointestinal symptoms, such as 

eye and joint pain, headaches, dizziness, and fatigue (Hunter et al., 2004). There is no treatment 

that can eliminate a Cryptosporidium infection, and only a few antiparasite or antimicrobial 

agents have shown even a slight ability to reduce a patient’s parasite load (Guerrant, 1997). 

 In some occurrences, cryptosporidiosis can be fatal, particularly among subpopulations 

such as AIDS patients, the elderly with other underlying illnesses, and other immunocompromised individuals. In a Cryptosporidium outbreak in Milwaukee in 1994, which had an 

estimated 403,000 cases of illness (Kramer et al., 1996), 54 people died who had 

cryptosporidiosis listed on their death certificate. Of those 54 people, 46 also had AIDS listed as 

an underlying cause of death (Hoxie et al., 1997). 

Giardiasis is a protozoal infection that usually causes diarrhea, possibly accompanied by 

fever, nausea and abdominal cramps in individuals with healthy immune systems. It is caused by 

ingestion of Giardia cysts. 

In 2003, two 5-year-old boys living in the same water service area near Phoenix, AZ died 

in the same week from Primary Amoebic Meningioencephalitis (PAM) (Marciano-Cabral et al., 

2003). Both boys lived in homes supplied by untreated PWS wells. Atypically, the wells in that 

area provide water at elevated temperatures as a result of the elevated geothermal gradient in the 

subsurface. Seventeen samples taken from the boys homes were positive for Naegleria fowleri, 

and N. fowleri was also responsible for the boys’ deaths from PAM. It is likely that the elevated 
Economic Analysis for the Final RTCR 2-9 September 2012

ground water temperature provided a suitable habitat for N. fowleri colonization and growth 

either in the aquifer, the well, the distribution system, or the household plumbing. 

2.2.2 Total Coliforms as Indicators of Treatment Effectiveness and Integrity of the 

Distribution System 

TC is a group of closely related bacteria that, with a few exceptions, are not harmful to 

humans. Many bacteria in the TC group are soil bacteria but some, such as E. coli, originate in 

the gut of warm-blooded animals. Coliform bacteria may be transported to surface water by 

runoff or to ground water by infiltration. TCs are common in ambient water and may be injured 

by environmental stresses such as lack of nutrients, and water treatment, such as chlorine 

disinfection, in a manner similar to most bacterial pathogens and many viral enteric pathogens 

(including fecal pathogens). EPA considers TC to be a useful indicator of a potential pathway 

through which fecal contamination can enter the distribution system. The absence (versus the 

presence) of TC in the distribution system indicates a reduced likelihood that fecal contamination 

and/or waterborne pathogens are occurring in the distribution system. 

Under the 1989 TCR, each TC-positive sample is assayed for either FC or E. coli. Fecal 

coliform bacteria are a subgroup of TC that traditionally has been associated with fecal 

contamination. Since the promulgation of the TCR, more information and understanding of the 

suitability of FC and E. coli as indicators have become available. Study has shown that the FC

assay is imprecise and too often captures bacteria that do not originate in the human or mammal 

gut (Edberg et al., 2000). On the other hand, E. coli is a more restricted group of coliform 

bacteria that almost always originate in the human or animal gut (Edberg et al., 2000). Thus, E. 

coli is a better indicator of fecal contamination than FC. 

2.2.3 Sanitary Defects 

As part of the RTCR, TC is used as an indicator to start an evaluation process that, where 

necessary, will require the PWS to correct sanitary defects, which are defined as “a defect that 

could provide a pathway of entry for microbial contamination into the distribution system or that 

is indicative of a failure or imminent failure in a barrier that is already in place.” “Sanitary 

defect” is a term specific to the TCR assessment and correction provisions. Sanitary defects are 

not intended to be linked directly to the “significant deficiencies” under the SWTR and GWR, 

although some problems could meet either definition. The RTCR is not intended to limit the 

existing authorities of primacy agencies under other regulations. Primacy agencies may allow for 

integrated assessments meeting the requirements of multiple rules, where appropriate (see 

Chapter 3 of this EA for more details on the provisions of the RTCR). 

2.2.4 Occurrence of Fecal Contamination and/or Waterborne Pathogens 

2.2.4.1 Presence of Fecal Contamination 

Fecal contamination is a very general term that includes all of the organisms found in 

feces, both pathogenic and nonpathogenic. Fecal contamination can occur in drinking water both 

through use of contaminated source water as well as direct intrusion into the drinking water 

distribution system. Biofilms in distribution systems may harbor waterborne pathogens and 

accumulate enteric viruses and parasitic protozoa (Skraber et al., 2005; Helmi et al., 2008). 
Economic Analysis for the Final RTCR 2-10 September 2012

Waterborne pathogens harbored and accumulated in biofilms may have originally entered the 

distribution system as fecal contamination from humans or animals. 

EPA believes that E. coli is a meaningful indicator for fecal contamination and the 

potential presence of associated pathogen occurrence. However, co-occurrence of indicators and 

waterborne pathogens is difficult to measure. The analytical methods approved by EPA to assay 

for E. coli do not specifically identify most of the pathogenic E. coli strains. There are at least 

700 recognized E. coli strains. About 10 percent of the recognized E. coli strains are pathogenic 

to humans (Feng, 1995; Hussein, 2007; Kaper et al., 2004). Because EPA-approved standard 

methods for E. coli do not typically identify the presence of the pathogenic E. coli strains, an E. 

coli-positive monitoring result is an indicator of fecal contamination but is not necessarily a 

definitive measure of waterborne pathogen occurrence. Specialized assays and methods must be 

used to identify waterborne pathogens, including pathogenic E. coli. These specialized assays 

and methods are generally considered too costly and time consuming to be effective for routine 

monitoring of drinking water distribution systems. 

One notable exception is the data reported by Cooley et al. (2007), which showed high 

concentrations of pathogenic E. coli strains in samples containing high concentrations of fecal 

indicator E. coli. These data are from streams and other poor quality surface waters surrounding 

California spinach fields associated with the recent E. coli O157:H7 foodborne outbreak. Data 

equivalent to these are not available from drinking water samples collected under the 1989 TCR. 

2.2.4.2 Waterborne Disease Outbreaks 

The CDC defines a waterborne disease outbreak as occurring when at least two persons 

experience a similar illness, or one person is ill with amoebic meningioencephalitis, after the 

ingestion of drinking water or following exposure to water used for recreational purposes, in 

cases where the epidemiologic evidence implicates water as the probable source of the illness 

(Kramer et al., 1996). The CDC maintains a database on waterborne disease outbreaks in the 

United States. The database is based upon responses to a voluntary and confidential survey form 

that is completed by state and local public health officials. 

The National Research Council strongly suggests that the number of identified and 

reported outbreaks in the CDC database for surface and ground waters represents only a small 

percentage of the actual number of waterborne disease outbreaks (NRC, 1997; Bennett et al., 

1987, Hopkins et al.,1985 for Colorado data). Underreporting occurs because most waterborne 

outbreaks in community water systems are not recognized until a sizable proportion of the 

population is ill (Perz et al., 1998; Craun, 1996), perhaps 1 to 2 percent of the population (Craun, 

1996). 

EPA drinking water regulations are designed to protect against endemic waterborne 

disease and to minimize waterborne outbreaks. Endemic waterborne disease may be defined as 

any waterborne disease not associated with an outbreak. 
Economic Analysis for the Final RTCR 2-11 September 2012

2.3 Statutory Authority for Promulgating the Rule 

As mentioned previously, SDWA requires EPA to review and revise, as appropriate, each 

existing NPDWR at least once every six years (SDWA section 1412(b)(9), 42 U.S.C. § 300g1(b)(9)). Section 1412(b)(9) of SDWA states: 

The Administrator shall, not less often than every 6 years, review and revise, as 

appropriate, each national primary drinking water regulation promulgated under this title. 

Any revision of a national primary drinking water regulation shall be promulgated in 

accordance with this section, except that each revision shall maintain, or provide for 

greater, protection of the health of persons. 

In 2003, EPA completed its review of the 1989 TCR and 68 NPDWRs for chemicals that 

were established prior to 1997 (USEPA 2002b, 67 FR 19030, April 17, 2002). In the Six-Year 

Review determination published in July 2003, EPA stated its intent to revise the 1989 TCR 

(USEPA 2003b, 68 FR 42907, July 18, 2003). 

2.4 Economic Rationale 

As a revision to an existing regulation, the primary goal of the RTCR is to achieve the 

objectives of the 1989 TCR more effectively and efficiently, taking into account the changes in 

regulatory framework for implementing the SDWA over the past 20 years and experience with 

the 1989 TCR since promulgation. In this context, the overall economic rationale behind the 

promulgation of the RTCR is the same as the rationale for the promulgation of the 1989 TCR. 

This section addresses the economic rationale for choosing a regulatory approach under the 

RTCR (and 1989 TCR) rather than non-regulatory options. 

An economic rationale for the rule is required by Executive Order 12866, Regulatory 

Planning and Review (58 FR 51735, October 1993), which states: 

“[E]ach agency shall identify the problem that it intends to address (including, where

applicable, the failures of the private markets or public institutions that warrant new 

agency action) as well as assess the significance of that problem.” (Section 1, b(1))

In addition, Office of Management and Budget (OMB) guidance, dated January 11, 1996, 

states that “in order to establish the need for the proposed action, the analysis should discuss 

whether the problem constitutes a significant market failure” (OMB, 1996). 

In a perfectly competitive market, prices and quantities are determined solely by the 

aggregated decisions of buyers and sellers. Such a market occurs when many producers of a 

product are selling to many buyers, and where both producers and consumers have perfect 

information on the characteristics and prices of each firm’s products. Barriers to entry in the 

industry cannot exist, and individual buyers and sellers must be “price takers” (i.e., their 

individual decisions cannot affect the price). Several properties of the public water supply do not 

satisfy the conditions for a perfectly competitive market and thus lead to market failures that 

require regulation. 
Economic Analysis for the Final RTCR 2-12 September 2012

Many PWSs are natural monopolies. A natural monopoly exists when it is impossible for 

more than one firm in each area to recover the costs of production and survive. There are high 

fixed costs associated with reservoirs and wells, transmission and distribution systems, treatment 

plants, and other facilities. For other potential suppliers to enter the market, they would have to 

provide the same extensive infrastructure to realize similar economies of scale and be 

competitive. A splitting of the market with increased fixed costs (e.g., two supplier networks in a 

single market) usually makes this situation unprofitable. The result is a market suitable for a 

single supplier and hostile to alternative suppliers. In such natural monopolies, suppliers have 

fewer incentives for providing quality services or maintaining competitive prices. In these 

situations, governments often intervene to help protect the public interest. 

For example, because PWSs are legal, as well as natural, monopolies, they are often 

subject to price controls, if not outright public ownership. While customers may demand 

improvements in water quality, the regulatory structure may not facilitate the transmission of that 

demand to the water supplier or allow the supplier to raise its price to recover the cost of the 

improvements. If consumers do not believe that their drinking water is safe enough, they cannot 

simply switch to another water utility. Other options for obtaining safe drinking water (e.g., 

buying bottled water or installing point of use filtration) most often represent a higher water cost 

to consumers than the purchase from PWSs. Therefore, the water supplier may have little 

incentive to improve water quality. 

The public may also not understand the health and safety issues associated with poor 

drinking water quality. Understanding the health risks posed by trace quantities of drinking water 

contaminants involves analysis and synthesis of complex toxicological and health sciences data. 

Therefore, the public may not be aware of the risks it faces. EPA has implemented a Consumer 

Confidence Reports (CCR) Rule (USEPA, 1998b, 63 FR 44512, August 1998) that makes water 

quality information more easily available to consumers. This rule requires CWSs to publish an 

annual report on local drinking water quality. Consumers, however, still have to analyze this 

information for its health risk implications. Furthermore, even if informed consumers are able to 

engage PWSs in a dialogue about health issues, the transaction costs of such interaction 

(measured in personal time and monetary outlays) present another significant impediment to 

consumer expression of risk reduction preferences. 

SDWA regulations are intended to provide a level of protection from exposure to 

drinking water contaminants. The regulations set minimum performance requirements to protect 

consumers from exposure to contaminants. SDWA regulations are not intended to restructure 

market mechanisms or to establish competition in supply; rather, they establish the level of 

service to be provided that best reflects public preference for safety. The federal regulations 

reduce the high information and transaction costs by acting on behalf of consumers in balancing 

risk reduction and the social costs of achieving this risk reduction. 
Economic Analysis for the Final RTCR 3-1 September 2012

3 Consideration of Regulatory Options 

3.1 Introduction 

This chapter describes the regulatory options considered during the development of the 

Revised Total Coliform Rule (RTCR) and evaluated as part of this economic analysis (EA). 

3.2 Total Coliform Rule/Distribution System Advisory Committee 

In the July 2003 NPDWR review decision, EPA provided public notice of its intent to 

revise the 1989 TCR. In 2007, EPA decided to establish a committee under the Federal Advisory 

Committee Act (FACA) called the Total Coliform Rule/Distribution System Advisory 

Committee (TCRDSAC) (USEPA, 2007a). The advisory committee was charged with 

developing an Agreement in Principle (AIP) 7 with recommendations for the revision of the 1989 

TCR. The advisory committee was to also provide EPA with recommendations needed to 

understand and address possible public health impacts from potential degradation of drinking 

water quality in distribution systems. Specifically, the major objectives of the advisory 

committee were to provide advice and recommendations on: 

 Revisions to the 1989 TCR that would improve implementation while maintaining 

or improving public health protection and distribution system water quality. 

Examples of the issues the TCRDSAC considered include: the 1989 TCR 

monitoring framework, sanitary survey provisions, definition of maximum 

contaminant level (MCL) violations and potential follow-up corrective actions, and 

public notification of violations. 

 What data should be collected, research conducted, and/or risk management 

strategies evaluated to better project distribution system contaminant occurrence 

and associated public health risks in the distribution systems. This was intended to 

“initiate a process for addressing cross connection control and backflow prevention 

requirements and consider additional distribution system requirements related to 

significant health risks” as recommended by the M/DBP Federal Advisory 

Committee. 

EPA held a series of 13 meetings of the advisory committee between July 2007 and 

September 2008. The 15 committee members, along with other stakeholders, discussed options 

for revising the 1989 TCR and began the process of developing the RTCR by discussing the 

purpose, efficacy and applicability of the 1989 TCR, as well as data collection and research 

needed to better understand potential distribution system risks. The advisory committee formed a 

Technical Work Group (TWG) to provide data analysis and information to inform the advisory 

committee’s discussions. The advisory committee also discussed the relevant provisions of the 

Ground Water Rule (GWR) and discussed the extent to which other rules contribute to the 

objectives of the 1989 TCR. All advisory committee members signed the AIP in September 

2008. All of the recommendations of the AIP, on which all the members of the committee 

 

7

 Under the proposed rule, the preferred regulatory option was called Agreement in Principle (AIP). Under the final 

rule, the preferred regulatory option is called the RTCR. 
agreed, are found in the signed AIP (USEPA 2009, 74 FR 1683, January 13, 2009). The AIP and 

details about the advisory committee can be found at EPA’s website at: 

http://water.epa.gov/lawsregs/rulesregs/sdwa/tcr/regulation_revisions_tcrdsac.cfm. 

3.3 Regulatory Options Considered 

EPA evaluated three regulatory options as part of the development of the RTCR—the 

1989 TCR, the RTCR, and the Alternative option. The following discussion provides an 

overview of the three regulatory options considered followed by a detailed table comparing 

specific regulatory components. A detailed evaluation and comparison of the benefits and costs 

of each of the three regulatory options for the RTCR is found in later chapters of this EA. 

Baseline Option: 1989 Total Coliform Rule 

The baseline option for the EA is the 1989 TCR as written, with adjustments made to 

reflect the requirements of the GWR that PWSs must comply with beginning December 1, 2009. 

Analysis of this option is primarily based on data collected under the 1989 TCR, as described in 

Chapter 4 (Baseline Conditions) of this EA. 

The 1989 TCR requires public water systems (PWSs) to monitor routinely for total 

coliforms (TC) and fecal coliforms (FC) or E. coli. Monitoring requirements are based on system 

type, population served by the PWS and source water type. Each PWS must sample according to 

a written sample siting plan. Plans are subject to state review and revision. 

The 1989 TCR specifies a maximum contaminant level goal (MCLG) of zero for TC 

(including FC and E. coli) as well as an MCL where compliance is based on the presence or 

absence of TC and/or FC or E. coli in the samples. A PWS is required to take repeat samples 

following a total coliform-positive (TC+) sample and to test the TC+ sample for E. coli. A 

monthly MCL violation is triggered if: (1) a PWS collecting fewer than 40 samples per month 

has >1 TC+ sample per month; or (2) a PWS collecting at least 40 samples per month has >5.0% 

TC+ samples per month. An acute MCL violation is triggered if any PWS has any fecal 

coliform- or E. coli -positive (FC+ / EC+) repeat sample or has a FC+ or EC+ routine sample 

followed by a TC+ repeat sample. A PWS must demonstrate compliance with the MCL for TC

each month it serves water to the public (or each calendar month that sampling occurs for PWSs 

on reduced monitoring). MCL violations must be reported to the state no later than the end of the 

next business day after the PWS learns of the violation. The public must also be notified 

depending on the severity of the MCL violation (within 30 days for monthly MCL violations and 

within 24 hours for acute MCL violations). 

RTCR 

The RTCR is designed to trigger PWSs that exceed specified levels of TC/E. coli in their 

finished water to do an assessment, to identify whether sanitary defects are present, and to 

correct such defects accordingly. EPA believes that the RTCR is an improvement over the 1989 

TCR framework because it takes a more preventive approach to identifying and fixing problems 

with public health implications. Under the RTCR, EPA establishes an MCLG of zero for E. coli, 

an MCL for E. coli based on TC and E. coli monitoring results, and a coliform treatment 

technique for protection against potential fecal contamination. 

Economic Analysis for the Final RTCR 3-2 September 2012
Economic Analysis for the Final RTCR 3-3 September 2012

On July 14, 2010, EPA proposed a RTCR that had the same elements and effect as the 

recommendations in the advisory committee AIP (USEPA 2010b, 75 FR 40926, July 14, 2010). 

The final RTCR was developed based on the proposed rule and the comments received on it. The 

RTCR maintains the 1989 TCR requirement for all PWSs to monitor for TC and E. coli 

according to a sample siting plan and schedule specific to the PWS. PWSs are required to take 

repeat samples and to test for E. coli following a TC+ sample. 

Under the RTCR, the PWS monitoring frequencies take into account the unique 

characteristics of various PWS types and sizes. Small, well-operated PWSs using ground water 

may be able to reduce monitoring frequencies by meeting specific criteria, thus reducing their 

monitoring and reporting burden. Criteria for reduced monitoring includes monitoring results 

that reflect a clean compliance history for a minimum of 12 months as well as preventive 

practices designed to continue to maintain the integrity of the distribution system. 

The RTCR requires PWSs to complete either Level 1 or Level 2 assessments following 

certain triggers (see Exhibit 3.1). The purpose of Level 1 and 2 assessments is to identify the 

presence of sanitary defects and deficiencies in distribution system coliform monitoring 

practices. The minimum elements of both Level 1 and 2 assessments include review and 

identification of: 

 Atypical events that may affect distributed water quality or indicate that distributed 

water quality was impaired; 

 Changes in distribution system maintenance and operation that may affect 

distributed water quality (including water storage); 

 Source and treatment considerations that bear on distributed water quality, where 

appropriate (e.g., whether a ground water system is disinfected) 

 Existing water quality monitoring data; and 

 Inadequacies in sample sites, sampling protocol, and sample processing. 

A Level 1 assessment (completed by the PWS) consists of a simple examination of the 

system and relevant operational practices. The PWS must complete the assessment form and 

submit it to the state for review within 30 days after determination that the PWS has exceeded 

the Level 1 trigger. The completed assessment form must include assessments conducted, all 

sanitary defects identified (or indicate if no sanitary defects were found), corrective actions 

completed, and a timetable for any corrective actions not already completed. Upon completion 

and submission of the assessment form by the PWS, the state will determine if the PWS has 

identified a likely cause for the Level 1 trigger and determine whether the PWS has corrected the 

problem, or has included a schedule acceptable to the state for correcting the problem. Whether 

or not the system has identified any sanitary defects or a likely cause for the Level 1 trigger, the 

state may determine whether or not the Level 1 assessment is sufficient, and if it is not the state 

must discuss its concerns with the system. The state may require revisions to the assessment after 

the consultation. If the state requires revision after consultation, the PWS must submit a revised 

assessment form to the state on an agreed-upon schedule not to exceed 30 days from the date of 

consultation. Upon completion and submission of the assessment form by the PWS, the state 
Economic Analysis for the Final RTCR 3-4 September 2012

must determine if the PWS has identified a likely cause for the Level 1 trigger and, if so, 

establish that the PWS has corrected the problem, or has included a schedule acceptable to the 

state for correcting the problem. 

The Level 2 assessment must be conducted either by the state, a third party approved by 

the state, or the PWS where the PWS has the staff or management with the required certification 

or qualifications specified by the state. A Level 2 assessment is a more detailed examination of 

the system’s monitoring and operational practices than a Level 1 assessment. As with the Level 1 

assessment, the completed assessment form for a Level 2 assessment must also be submitted to 

the state for review within 30 days after determination that the PWS has exceeded the Level 2 

trigger. The PWS must also indicate in the completed assessment form the sanitary defects 

detected (or indicate if no sanitary defects were found), corrective actions completed, and a 

timetable for any corrective actions not already completed. Upon completion and submission of 

the assessment form by the PWS, the state will determine if the PWS has identified a likely cause 

for the Level 2 trigger and determine whether the PWS has corrected the problem, or has 

included a schedule acceptable to the state for correcting the problem. Whether or not the system 

has identified any sanitary defects or a likely cause for the Level 2 trigger, the state may 

determine whether or not the Level 2 assessment is sufficient, and if it is not the state must 

discuss its concerns with the system. The state may require revisions to the assessment after the 

consultation. If the state requires revision after consultation, the PWS must submit a revised 

assessment form to the state on an agreed-upon schedule not to exceed 30 days from the date of 

consultation. Upon completion and submission of the assessment form by the PWS, the state 

must determine if the PWS has identified a likely cause for the Level 2 trigger and, if so, 

establish that the PWS has corrected the problem, or has included a schedule acceptable to the 

state for correcting the problem. 

The RTCR requires PWSs to correct sanitary defects found through either a Level 1 or 

Level 2 assessment. The 1989 TCR does not require PWSs that have TC MCL violations to 

perform corrective actions. For corrections that are not completed by the time the PWS submits 

the completed assessment form to the state, the PWS must complete the corrective action(s) on a 

schedule determined by the state in consultation with the PWS. The PWS must notify the state 

when each scheduled corrective action is completed. 

The RTCR specifies violations corresponding to different degrees of potential public 

health concern and public notification. A violation of an E. coli MCL occurs when: 

 A routine sample is TC+ and one of its associated repeat samples is EC+; or 

 A routine sample is EC+ and one of its associated repeat samples is TC+ or EC+; or 

 A system fails to test for E. coli when any repeat sample is TC+; or 

 A system fails to take all required repeat samples following a routine sample that is 

EC+. 

An E. coli MCL violation requires a Tier 1 public notification. A coliform treatment 

technique violation occurs when the PWS exceeds a treatment technique trigger (see Exhibit 3.1) 

and then fails to conduct the required assessment or corrective action within the required 
Economic Analysis for the Final RTCR 3-5 September 2012

timeframes. A coliform treatment technique violation requires a Tier 2 public notification. If the 

system does conduct the assessment and satisfies the requirements of the coliform treatment 

technique (including corrective action when a sanitary defect is identified), no public notification 

is required. A monitoring violation occurs when a PWS fails (1) to take every required routine or 

additional routine sample in a compliance period, or (2) to analyze for E. coli following a TC+ 

sample. A reporting violation occurs when (1) a PWS properly conducts monitoring or an 

assessment but fails to submit a monitoring report or a completed assessment form, or (2) a PWS 

fails to notify the state following an EC+ sample. Both monitoring violations and reporting 

violations require a Tier 3 public notification, but community water systems can use their annual 

consumer confidence report to complete the notification. 

The provisions of the RTCR consider the implication and linkages to other rules 

promulgated by EPA under SDWA (e.g., GWR, Surface Water Treatment Rules (SWTRs), and 

the Disinfectant/ Disinfection Byproduct (DBP) Rules (USEPA, 1998c)). Compliance activities 

for other rules, such as the sanitary survey, are used under the RTCR as criteria to assess the 

integrity of the PWS and to implement the reduced monitoring provisions in a cost-effective 

manner. By January 2015 ground water PWSs will have completed at least one round of the 

sanitary survey component of the GWR. Therefore, sanitary survey findings can be used by 

states in the determination of the monitoring frequency. 

Alternative Option: All PWSs Initially Sample for TC/EC on Monthly Basis 

The third option is the Alternative option which parallels the RTCR in most ways but 

includes variations of some of the provisions that were discussed by the advisory committee 

before consensus was reached on the RTCR. Under the Alternative option, at the compliance 

date, all PWSs would be required to sample monthly for an initial period until they meet the 

eligibility criteria for reduced monitoring. This more stringent approach differs from the RTCR. 

Under the RTCR PWSs are allowed to continue to monitor at their current frequencies (with an 

additional annual site visit / voluntary Level 2 assessment for PWSs wishing to remain on annual 

monitoring) until they are triggered into an increased sampling frequency. Under the Alternative 

option, however, no PWSs would be allowed to reduce monitoring to an annual basis. EPA 

defined the Alternative option this way and included it in the economic analysis to assess the 

relative impacts of a more stringent rule and to better understand the balance between costs and 

public health protection. 

3.3.1 Comparative Summary of Regulatory Options 

Exhibit 3.1 below summarizes the components of each regulatory option considered for 

the RTCR. 
Economic Analysis for the Final RTCR 3-6 September 2012

Exhibit 3.1 Comparison of RTCR Regulatory Options 

Element 1989 TCR RTCR Alternative option

Rule construct  MCLG of zero for TC (including 

FC and EC).

 TC monthly MCL based on the 

number/percent of TC+ samples 

in a month.

 FC/EC acute MCL based on 

FC+/EC+ samples.

 Public Notification required for 

MCL violations, including the TC 

monthly MCL violation based only 

on TC occurrence.

 No MCLG/MCL for TC, FC no longer used.

 EC MCLG of zero, and an EC MCL and a coliform treatment 

technique based on TC and/or EC results.

 Assessment (and corrective action if necessary) required if 

PWS has a coliform treatment technique trigger.

 Public Notification not required for only TC occurrence.

Same as RTCR.

Transition to the 

New Rule

N/A  PWSs continue on their 1989 TCR monitoring schedule 

provided they meet criteria. 

 Noncommunity Water Systems (NCWSs) on quarterly/annual 

monitoring remain on that schedule unless/until they have an 

event that triggers increased monitoring. 

 Community Water Systems (CWSs) on reduced monitoring 

remain on that schedule unless/until they have an event that 

triggers return to routine monitoring.

 Monitoring schedules will be evaluated during the “special 

monitoring evaluation” conducted by the state as part of the

periodic sanitary survey to determine if the monitoring 

frequency is appropriate. The first such evaluation must be 

conducted during the first scheduled sanitary survey after the 

effective date of the rule; a system may remain on its 1989 

TCR monitoring schedule until this time unless it is triggered 

into more frequent monitoring. 

No transition. PWSs 

start new requirements 

as soon as the rule is 

effective.
Economic Analysis for the Final RTCR 3-7 September 2012

Element 1989 TCR RTCR Alternative option

Routine 

Monitoring 

 1 sample per quarter for NCWS 

≤1,000 Ground Water (GW).

 1 sample per month for NCWS 

≤1,000 Surface Water (SW) and 

all CWS ≤1,000.

 For all PWS >1,000, the number 

of samples per month is based 

on population served and 

specified in the rule.

 1 sample per month for seasonal NCWS ≤1,000 (GW)8 with 

criteria to qualify for reduced monitoring. Seasonal systems 

must also demonstrate completion of a state-approved startup procedure.

 For all others, same as 1989 TCR, with more explicit criteria 

to qualify for reduced monitoring (see “Reduced Monitoring” in 

this exhibit).

A minimum frequency 

of monthly monitoring 

for all PWSs. 

Reduced 

Monitoring

 NCWS ≤1,000 (GW) can reduce 

to 1 sample per year if system is 

free of sanitary defects.

 CWS ≤1,000 (GW) can reduce to 

1 sample per quarter if no history 

of TC contamination, no sanitary 

defects, and protected GW 

source.

 No other systems are eligible for 

reduced monitoring.

 NCWS ≤ 1,000 (GW)—same as in 1989 TCR, but more 

criteria to qualify and remain on reduced annual monitoring. 

o Most recent sanitary survey shows that system is free of 

sanitary defects,9has a protected water source, and meets 

approved construction standards;

o Clean compliance history for a minimum of 12 months;

o Level 2 assessment by party approved by state within the 

last 12 months and correction of all identified sanitary 

defects. System must also have an annual site visit every 

year thereafter to remain on annual monitoring. 

 Seasonal NCWS ≤ 1,000 (GW) can be eligible for reduced 

monitoring by having an approved sample site plan that 

designates the time period for monitoring based on sitespecific considerations (e.g., during periods of highest 

demand or highest vulnerability to contamination). The 

system must collect compliance samples during this time. 

o For reduced quarterly monitoring the seasonal system must 

have a sanitary survey or site visit or Level 2 assessment 

within last 12 months; a protected water source; a clean 

 NCWS ≤ 1,000 (GW) 

(including seasonal 

systems)—reduced 

quarterly monitoring 

(criteria same as 

RTCR). Reduced 

annual monitoring is 

not allowed. 

 CWS ≤ 1,000 

(GW)—same as 

RTCR.

 No other systems 

are eligible for 

reduced monitoring.

 

8 A seasonal system is a non-community water system that is not operated as a public water system on a year-round basis and starts up and shuts down the system 

at the beginning and end of each operating season (§141.851 of the RTCR). 

9 The RTCR defines a sanitary defect as “a defect that could provide a pathway of entry for microbial contamination into the distribution system or that is 

indicative of a failure or imminent failure in a barrier that is already in place”
Economic Analysis for the Final RTCR 3-8 September 2012

Element 1989 TCR RTCR Alternative option

compliance history for a minimum of 12 months, and be 

free of sanitary defects. 

o To reduce to 1 sample per year, the seasonal system must 

meet the criteria specified above for quarterly monitoring 

and have in place or adopt one or more additional 

enhancements to barriers to contamination (cross 

connection control, certified operator, meet disinfection 

criteria, maintenance of at least 4-log removal or 

inactivation of viruses, other equivalent enhancements).

 CWS ≤ 1,000 (GW)—same as in 1989 TCR, but more criteria 

to qualify and remain on reduced quarterly monitoring.

o State certified operator;

o Most recent sanitary survey shows that system is free of 

sanitary defects (or has an approved plan and schedule to 

correct them), has a protected water source, and meets 

approved construction standards;

o Clean compliance history for a minimum of 12 months;

o Meets at least one of the following criteria: annual site visit 

by the state or a voluntary Level 2 assessment by a party 

approved by the state or meeting criteria established by the 

state; cross connection control; meet disinfection criteria; 

maintenance of at least 4-log removal or inactivation of 

viruses; other equivalent enhancements to water systems 

as approved by the state.

 No other systems are eligible for reduced monitoring.

Increased 

Monitoring

(NCWS) and 

Return to Routine 

Monitoring (CWS)

 N/A (none specified)—NCWS.

 N/A (none specified)—CWS 

 NCWS ≤ 1,000 (GW only) increases from quarterly or annual 

monitoring to monthly monitoring if one of the following 

occurs: 

o Triggered Level 2 assessment or a 2nd Level 1 assessment 

in 12 months;

o EC MCL violation;

o Treatment technique violation;

o Two monitoring violations within 12 months if on quarterly 

Same as RTCR with 

the exception that 

reduced annual 

monitoring is not 

allowed under this 

option.
Economic Analysis for the Final RTCR 3-9 September 2012

Element 1989 TCR RTCR Alternative option

monitoring; or

o One monitoring violation and one Level 1 assessment 

within 12 months if on quarterly monitoring.

 NCWS ≤ 1,000 (GW only) increases from quarterly 

monitoring to monthly monitoring if it has one monitoring 

violation and one Level 1 assessment within 12 months.

 NCWS ≤ 1,000 (GW only) increases from annual monitoring 

to quarterly monitoring if it has one monitoring violation.

 CWS ≤ 1,000 (GW only) on quarterly monitoring return to 

monthly monitoring based on the first four criteria that trigger 

a NCWS ≤ 1,000 (GW only) to increased its monitoring to 

monthly, as listed above.

Return to 

Reduced 

Monitoring (After 

Being Triggered 

to Increased 

Monitoring)

N/A  NCWS ≤ 1,000 (GW) must meet the following criteria to return 

to routine quarterly monitoring after being triggered to 

increased monitoring:

o Within the last 12 months, system must have completed a 

sanitary survey or a site visit by the state or a voluntary 

Level 2 assessment, must be free of sanitary defects, and 

must have a protected water source; and

o Clean compliance history for a minimum of 12 months.

 NCWS ≤ 1,000 (GW) must meet the following criteria to return 

to reduced annual monitoring in addition to meeting the 

criteria for returning to routine quarterly monitoring:

o An annual site visit by the state or a voluntary Level 2 

assessment and correction of all identified sanitary defects; 

and 

o Adoption of one or more additional enhancements to the 

water system barriers to contamination (cross connection 

control, certified operator, meet disinfection criteria, 

maintenance of at least 4-log removal or inactivation of 

viruses, other equivalent enhancements).

 CWS ≤ 1,000 (GW) must meet the same criteria for qualifying 

for reduced quarterly monitoring. 

Same as RTCR with 

the exception that 

reduced annual 

monitoring is not 

allowed under this 

option. 
Economic Analysis for the Final RTCR 3-10 September 2012

Element 1989 TCR RTCR Alternative option

Repeat 

Monitoring

 PWS serving >1,000 people must 

take 3 repeat samples after a 

TC+ sample. 

 PWS serving ≤1,000 must take 4 

repeat samples after a TC+ 

sample.

o For ground water systems, 1 

sample can be a source 

water sample to comply with 

the GWR.

 All PWSs must take 3 repeat samples after a TC+ sample.

o PWS ≤ 1,000, the number of repeat samples is reduced 

from 4 samples to 3.

 GW PWS must still take an additional source sample to 

comply with the GWR. 

 For GW PWS ≤ 1,000, a single sample can meet both the 

triggered source water requirements of the GWR and the 

repeat sample requirements of the RTCR, but only if the state

approves the use of the single sample to meet both rule 

requirements and the use of EC as the fecal indicator.

Same as RTCR.

Additional 

Routine 

Monitoring

PWS taking <5 routine samples per 

month (PWS serving ≤ 4,100) must 

take at least 5 routine samples the 

month after a TC+ sample.

 For PWS taking samples less than monthly, the number of 

samples required after a TC+ is reduced from 5 to 3.

 For PWS taking at least 1 sample per month, the additional 

routine sample requirement is eliminated (they take their 

usual number of samples the following month).

Same as RTCR.

Sample Siting 

Plan

 Sampling must occur at sites 

representative of water quality in 

the distribution system.

 Sample siting plans are subject to 

state review/ revision.

 Special purpose samples are not 

used for determining compliance.

 Take at least one repeat sample 

within 5 connections up- and 

downstream of the TC+ site.

Same as 1989 TCR except:

 Specifically allows for dedicated sampling stations.

 Provides more flexibility for systems in determining the

locations for taking repeat samples. For systems that want to 

establish repeat sampling locations other than the within-fiveconnections-upstream-and-downstream of the TC-positive 

sample, the system must submit the sample siting plan for 

review and the state may modify the sampling locations as 

needed.

 States may allow entry point sampling at ground water 

systems if the overall plan remains representative of water 

quality in the distribution system.

Same as RTCR.

Assessment N/A—none required under the 

1989 TCR.

 The PWS must conduct a Level 1 (self-assessment) if it 

exceeds any of the following triggers:

o For systems taking ≥40 samples per month, the PWS 

Same as RTCR.
Economic Analysis for the Final RTCR 3-11 September 2012

Element 1989 TCR RTCR Alternative option

exceeds 5.0% TC+ samples for the month; or

o For systems taking <40 samples per month, the PWS has ≥

2 TC+ samples for the month; or

o The PWS fails to take every required repeat sample after 

any single routine TC+ sample.

 The PWS must ensure that a Level 2 assessment is 

conducted either by the state or a state-approved 3rd party 

(including qualified PWS employee) if it exceeds any of the 

following triggers:

o The PWS has an E. coli MCL violation.

o The PWS has a second Level 1 trigger within a rolling 12-

month period, or in 2 consecutive years for systems on 

annual monitoring.

 Assessment results and description of corrective action taken 

will be submitted to the state within 30 days.

Corrective Action N/A—none required under the 

1989 TCR.

 System must correct all sanitary defects found in the 

assessment.

 State must be satisfied with the assessment.

 For corrections not completed by the time the assessment 

form is submitted, the systems must be in compliance with a 

state determined schedule and must notify the state when 

completed.

Same as RTCR.
Economic Analysis for the Final RTCR 3-12 September 2012

Element 1989 TCR RTCR Alternative option

Violations and 

Public 

Notification 

 EC/FC MCL violation—acute 

violation, Tier 1 Public 

Notification.

 Monthly TC MCL violation—Tier 

2 Public Notification. 

 Monitoring or reporting 

violation—Tier 3 Public 

Notification. 

 PWS must notify state regarding 

single EC+/FC+ result.

 EC MCL violation—Tier 1 Public Notification. Failure to take 

repeat samples following an EC+ is also an EC MCL violation.

 Monthly TC MCL violation is dropped—conditions that trigger 

a monthly TC MCL violation under the TCR trigger

assessment and corrective action instead.

 Coliform treatment technique violation occurs when a PWS 

fails to conduct required assessment and corrective action—

Tier 2 Public Notification.

 Monitoring and reporting violations will be tracked separately 

—Tier 3 Public Notification.

Same as RTCR.
Economic Analysis for the Final RTCR 3-13 September 2012

3.4 Final Rule Requirements 

Based on the recommendations in the AIP, as well as the comments received on the 

proposed RTCR during the public comment period, EPA selected the RTCR as the preferred 

regulatory option. The RTCR was developed by the EPA with the primary goal of achieving the 

objectives of the 1989 TCR more effectively and efficiently, taking into account the changes in 

regulatory framework for implementing the SDWA over the past 20 years and experience with 

the TCR since it was promulgated in 1989. Additional discussion supporting the selection of the 

RTCR as the preferred regulatory option in terms of benefits and costs is provided in Chapters 6 

(benefits), 7 (costs), and 9 (benefits and costs). For a detailed discussion of the requirements of 

the RTCR, see section III of the RTCR preamble and subpart Y of 40 CFR part 141.
Economic Analysis for the Final RTCR 4-1 September 2012

4 Baseline Conditions 

4.1 Introduction 

A primary step in the development of the economic analysis (EA) for the Revised Total 

Coliform Rule (RTCR) was to estimate the baseline conditions. The U.S. Environmental 

Protection Agency (EPA) used available data to develop an occurrence and predictive model for 

public water systems (PWSs) serving 4,100 people or fewer based primarily on the 2005 SixYear Review 2 data to predict total coliform (TC) and E. coli occurrence, Level 1 and Level 2 

assessment triggers, corrective actions, and violations, both in the baseline and over time. EPA 

developed another, simpler, predictive model for PWSs serving more than 4,100 people based 

primarily on the 2005 Safe Drinking Water Information System/Federal Version (SDWIS/FED) 

violation data (USEPA, 2005) that predicts triggers, assessments, corrective actions, and 

violations both in the baseline and over time, but not TC and E. coli occurrence. Because five 

years of Ground Water Rule (GWR) implementation prior to the effective date of the RTCR are 

expected to cause changes to ground water systems, the baseline conditions that EPA developed 

for the EA account for the effects of the GWR, as described in this chapter and Chapter 5. The 

remainder of this chapter describes the data sources used to develop the baselines and how the 

data were used. The resulting estimate of baseline conditions serves as a reference point for 

understanding net impacts of the RTCR, as discussed in Chapters 6, 7, and 9 of this EA. 

4.1.1 Background and Purpose 

The baseline analysis is a characterization of the water industry and its current operations 

in effect before systems make changes to meet requirements of the RTCR. This chapter presents 

estimates of the number of systems, the population affected, water quality measures, and 

subpopulations affected. The data collected for this profile serves as the baseline in the RTCR 

EA. The development of the baseline analysis consisted of the following steps: 

 Compilation of a profile of water systems—identifying and collecting information 

on all PWSs. 

 Characterization of current monitoring requirements, including testing 

requirements, sample siting plans, routine and repeat sampling requirements, and 

sanitary surveys. 

 Characterization of current PWS compliance information, including acute and 

monthly maximum contaminant level (MCL) violations, triggered monitoring, and 

public notification reporting. 

4.1.2 Chapter Organization 

The remainder of this document is organized into four general sections: 

 Section 4.2 describes general information on data sources. 

 Section 4.3 describes the baseline conditions. 
Economic Analysis for the Final RTCR 4-2 September 2012

 Section 4.4 estimates baseline impact on sensitive populations. 

 Section 4.5 presents a summary of assumptions used to develop baseline estimates, 

associated uncertainty and variability, and potential impacts on the results of the 

RTCR EA. 

4.2 Data Sources 

Several primary data sources were used for the EA to characterize the RTCR baseline to 

create system and population baselines, including the SDWIS/FED (USEPA, 2007b), the 2005 

Six-Year Review of National Primary Drinking Water Regulations (Six-Year Review 2), the 

GWR EA, and the U.S. Census. Each of these data sources is further explained in Sections 4.2.1–

4.2.3 below. 

4.2.1 Background on SDWIS/FED Data 

SDWIS/FED10 is EPA’s national regulatory compliance database for the drinking water 

program and is the main source of PWS inventory and violation data for the RTCR baseline. 

SDWIS/FED contains information on each of the approximately 155,000 active PWSs as 

reported by primacy agencies,11 EPA Regions, and EPA headquarters personnel. SDWIS/FED 

does not include sample results, but does include identification of MCL violations and 

monitoring and reporting violations (both routine and repeat, and minor and major).12 It also 

contains information to characterize the U.S. inventory of PWSs, namely: system name and 

location; retail population served; source water type (i.e., ground water (GW), surface water 

(SW), or ground water under the direct influence of surface water (GWUDI)); whether or not 

systems disinfect the water; and PWS type, as described below. 

 

10 Further information on SDWIS/FED can be found on EPA’s website: 

http://www.epa.gov/safewater/databases/sdwis/index.html. 

11 States and Indian Tribes are given primary enforcement responsibility (primacy) for regulations pertaining to 

PWSs in their State/jurisdiction if they meet certain requirements specified under the primacy regulations at 

40CFR142, Subpart B. 

12 Under the 1989 Total Coliform Rule, violation categories are defined as follows (category names in bold). A nonacute (monthly) MCL violation occurs when >1 routine and/or repeat sample are total coliform-positive (TC+) for 

PWSs that take fewer than 40 samples monthly, or greater than 5.0% of monthly samples are TC+ for PWSs that 

take at least 40 samples. An acute MCL violation is triggered if a PWS has a fecal coliform-positive (FC+) or E. 

coli-positive repeat sample following a TC+ or has a FC+/EC+ routine sample followed by a TC+ repeat sample. A 

monitoring violation occurs when a PWS 1) does not satisfy the sample siting plan requirement; 2) does not sample 

in accordance with its required schedule; 3) does not analyze a TC+ routine sample for FC or E. coli; 4) does not 

collect repeat samples within 24 hours and analyze for TC following a routine TC+; or 5) does not test repeat 

samples that are TC+ for FC or E. coli. If a PWS fails to conduct some of the required routine samples in a 

compliance period, the PWS incurs a minor routine monitoring violation. Equivalently, a PWS that fails to 

conduct some or all of its required repeat samples following a TC+ routine sample incurs a minor repeat 

monitoring violation or a major repeat monitoring violation, respectively. Reporting violations occur when a 

PWS does not report to the state or to the public according to the schedule for each violation type. For acute MCL 

violations, a PWS must report to the state by end of day and to the public within 24 hours (by posting, hand delivery, 

or mass media subject to primacy agency approval). For monthly MCL violations, a PWS must report to the state by 

end of next day, and to the public within 30 days by mail, hand delivery, or other methods approved by the primacy 

agency. For monitoring violations, a PWS must notify the public with 1 year in accordance with general public 

notification requirements approved by the primacy agency. 
Economic Analysis for the Final RTCR 4-3 September 2012

EPA defines a PWS as a system that provides water for human consumption through 

pipes or other constructed conveyances if such a system has at least 15 service connections or 

regularly serves an average of at least 25 individuals per day for at least 60 days per year. PWSs 

are categorized as follows: 

 Community water systems (CWS) are PWSs that supply water to the same 

population year-round. 

 Noncommunity water systems (NCWS) are PWSs that supply water to a varying 

population or one that is served less than year-round. They are sub-categorized as 

follows: 

– Nontransient noncommunity water systems (NTNCWS) are PWSs that are 

not CWSs and that regularly supply water to at least 25 of the same people 

at least six months per year, for example, schools. 

– Transient noncommunity water systems (TNCWS) are NCWSs that 

provide water in places such as gas stations or campgrounds where people 

do not remain for long periods of time. 

Additionally, PWS are analyzed in this EA according to categories defined by the number 

of people they serve. The following nine categories of populations served by PWSs are used 

throughout this document: 

 ≤100

101–500

501–1,000

1,001–4,100 

4,101–33,000 

33,001–96,000 

96,001–500,000 

501,001–1 Million 

Over 1 Million 

















These population categories are mostly consistent with those analyzed for other rules and 

consider the distinctions in cost and system operation that are meaningful when considering the 

economic effects of rule requirements. In particular, under the 1989 TCR, PWSs serving more 

than 1,000 people all test for TC monthly; PWSs serving fewer than 1,000 people may monitor 

quarterly or even annually and (assuming that they collect fewer than 5 samples per month) must 

have a sanitary survey every 5 years. The 33,000 threshold is significant as it corresponds with 

sampling requirements (at least 40 samples per month are taken) that affects how compliance 

with the rule is calculated. (PWSs serving >33,000 persons must take 40 or more samples in a 

month, and may trigger an MCL violation based on the percentage of total coliform-positive 

(TC+) samples, in this case, >5.0 percent.) Finally, the size category thresholds of 1,000; 4,100; 

33,000; and 96,000 are consistent with the size categories used in the 1989 TCR to determine the 

monitoring regimen. 
Economic Analysis for the Final RTCR 4-4 September 2012

4.2.1.1 Data Used from SDWIS/FED 

To create the system and population baseline, EPA obtained the most current PWS 

inventory data by downloading data from the 4th quarter of 2007 from SDWIS/FED (USEPA, 

2007b). These data represented all current, active PWSs and the population served by these 

systems at the time of the download. This information comprises the PWS inventory baseline for 

this EA, and is summarized in Section 4.3. 

EPA also used MCL violations data from SDWIS/FED to validate model predictions for 

systems serving ≤4,100 people as described in Section 5.3.3.2, and to predict E. coli (acute) 

MCL violations (1989 TCR, RTCR, and Alternative option), TC (non-acute or monthly) MCL 

violations (1989 TCR) and Level 1 and Level 2 assessment triggers (RTCR and Alternative 

option) for systems serving more than 4,100 people, as described in Section 4.3.4.2. 

4.2.1.2 Data Cleaning 

Data obtained from SDWIS/FED comprised PWS inventory data for the 4th quarter of 

2007 and violations data from 3rd quarter 2005. The 4th quarter inventory data included the 

number of each type of PWS and the retail population served by each system for all active 

PWSs, and was used from SDWIS/FED without manipulation for the purpose of this analysis. 

For the SDWIS/FED violations dataset, EPA excluded some data representing OH, tribes, and 

territories as described in Section 4.3.4.2. The data set taken from the 2005 Six-Year Review 2 

database was cleaned as described in Section 4.2.2 of this EA. 

4.2.1.3 Representativeness and Quality of SDWIS/FED Data 

As noted above, SDWIS/FED is the source of PWS inventory data, and includes 

information on all of the approximately 155,000 PWSs to the extent that such data was entered 

by primacy agencies, EPA Regions, and EPA headquarters personnel. In 1998, EPA began a 

major effort to assess the quality of the drinking water data in SDWIS, including performance of 

a data quality assessment that has been published triennially since 2002. The most recent report 

from this periodic assessment, the 2006 Drinking Water Data Reliability Analysis and Action 

Plan (2006 report) (USEPA, 2008a), evaluated data for 2002–2004 and found the PWS inventory 

data quality to be high (87 percent) and the 1989 TCR violations data quality to be moderately 

high (81 percent). For the PWS inventory data used in this analysis, EPA found specifically that: 

“...The overall data quality of the eight inventory (water system identification) 

parameters assessed was 87%. In other words, 87% of PWSs from data verification (DV)

13 states between 2002 and 2004 had consistent data for all eight inventory data elements 

between their state files and SDWIS/FED database, or 13% of PWSs had at least one data 

element reported with a discrepancy. The highest discrepancy rate was for the 

administrative contact address element.” 

 

13 EPA routinely evaluates state programs by conducting DV audits, which evaluate the accuracy of a state’s 

decisions regarding PWS compliance with SDWA regulations and the accuracy with which inventory and 

compliance data is reported (entered or uploaded into) SDWIS/FED. 
Economic Analysis for the Final RTCR 4-5 September 2012

The report’s assessment indicates a high degree of completeness and accuracy in 

inventory data submitted by states to SDWIS/FED, and suggests that the information is largely 

representative of the PWSs in the United States. Although the RTCR EA uses inventory data 

from 2007, the assessment above applies to the most recent period analyzed in this report (2002–

2004). EPA believes that the inventory data from SDWIS/FED in 2007 is also likely to be 

representative of the approximately 155,000 PWSs and that there is low uncertainty in the data 

with respect to numbers of systems, source water type, size classification, and disinfection 

status.14

For the 1989 TCR MCL violations data, the overall data quality estimate was 81 percent, 

based on a rating of 84 percent for completeness of data and 97 percent accuracy of the data in 

SDWIS/FED as compared to data observed in states’ databases during the verification process.15

As described in the report, the 84 percent completeness assessment indicates that for 

approximately 16 percent of those systems found by EPA to have 1989 TCR MCL violations, 

states did not report the data in SDWIS/FED. Additionally, data completeness for monitoring 

and reporting violations as a whole for all Safe Drinking Water Act (SDWA) rules in 

SDWIS/FED is low at 29 percent, although this metric specific to the 1989 TCR is not provided 

in the report. Low compliance with monitoring and reporting may occur if systems would rather 

incur a Monitoring/Reporting violation rather than risk an MCL violation by sampling. These 

factors together suggest that violation rates would likely be higher if systems were fully in 

compliance with monitoring and reporting requirements, and if states were fully reporting those 

results to SDWIS/FED. Despite this potential downward bias in the MCL violations data, the 

Total Coliform Rule Distribution System Advisory Committee (TCRDSAC) was still able to 

note systematic trends in the data (across time and among PWS types and sizes) and informed its 

decisions and recommendations based on key observations: 

 Most systems with violations were NCWSs. 

 Lower violation rates were observed among larger systems. 

 Higher violation rates were observed among GW systems than SW systems. 

 Lower violation rates were observed among disinfecting GW systems than other 

GW systems. 

 

14 In particular, in the 2006 report the disinfection status (disinfecting, nondisinfecting, or status unknown) inventory 

item was assessed at 99.3%, indicating that less than 1% of systems from DV states analyzed between 2002 and 

2004 had a discrepancy in this information between State files and SDWIS/FED. For the purpose of the RTCR EA, 

systems with status listed as “unknown” were included in the nondisinfecting group.

15 The Overall Data Quality Estimate in SDWIS/FED measures how many noncompliance determinations are 

correctly reported in SDWIS/FED among all noncompliance determinations (that are either violations or falsepositive violations). This quantity is estimated based on the violations confirmed by EPA and correctly reported to 

SDWIS/FED out of all violations found by EPA or in the state files and SDWIS/FED. When the false positive rate is 

0%, this measure is the product of Completeness and Accuracy. The False Positive rate of the violation data in 

SDWIS/FED describes how much of the reported violation data in SDWIS are, in fact, false violations, expressed as 

a percentage. Further description can be found in the 2006 Drinking Water Data Reliability Analysis and Action 

Plan (2006 report) (USEPA, 2008a). 
Economic Analysis for the Final RTCR 4-6 September 2012

An additional concern with the representativeness of the violations data in SDWIS/FED 

that would not be accounted for in the data quality estimate from the 2006 report is the potential 

bias introduced by oversampling. In a recent paper by (Bennear et al., 2009), the authors attempt 

to determine how often oversampling is an effort to “sample out” of a potential violation versus 

just over compliance—taking additional samples to increase the PWS’s diagnostic power is 

assessing the quality of the water. The authors suggested that strategic oversampling was 

occurring in the one state included in their analysis16 and suggested that some systems were 

reducing their probability of incurring monthly violations (on the basis of TC positives as a 

percent of total monthly samples taken) by increasing the total number of samples taken. 

Although the study was not broad enough in scope to warrant adjusting the data used from 

SDWIS/FED, the issue is included in the discussion of net benefits in Chapter 9 of this EA. 

4.2.2 Background on 2005 Six-Year Review 2 Data 

Through an information collection request (USEPA, 2006b), EPA requested that states 

voluntarily submit monitoring data (sample results) that were collected between January 1998 

and December 2005 that were available electronically for specified chemical, radiological, and 

microbiological contaminants. This request included data collected in compliance with the 1989 

TCR regarding the presence/absence of TC, E. coli, and/or fecal coliforms (FC) and any 

disinfection data collected at 1989 TCR monitoring sites. (SW systems are required to monitor 

for the presence of a disinfectant residual when collecting coliform samples in the distribution 

system.) 

These data are an important component in supporting EPA’s second Six-Year Review of 

national primary drinking water regulations (NPDWRs). EPA encouraged each primacy agency 

to submit its contaminant occurrence information because these data directly contribute to EPA’s 

understanding of national contaminant occurrence, populations exposed to regulated 

contaminants, and exposure reductions associated with the current regulations. 

EPA requested the 1989 TCR monitoring results with the intent of conducting analyses 

and developing models to assess the potential impacts of changes to the rule. Models of the 

occurrence of TC and E. coli were developed using the 1989 TCR data to assess revisions to 

monitoring requirements and compliance decisions for different types of PWSs as suggested by 

the stakeholders during the TCRDSAC process, described further in Chapter 3 of this EA. 

For the RTCR EA, EPA used the 2005 Six Year Review data to develop the key 

parameters used in the RTCR predictive model to forecast water quality (in terms of TC and E. 

coli occurrence) under the 1989 TCR, the RTCR, and the Alternative option. Additionally, 2005 

Six Year Review data was used to inform EPA’s assumptions regarding the proportion of GW 

systems serving 1,000 or fewer people that sample monthly, quarterly, or annually (presented in 

Exhibit 4.4). 

 

16 Bennear et al. found that violations in the state of Massachusetts may have been approximately 30% greater had 

the oversampling not taken place. 
Economic Analysis for the Final RTCR 4-7 September 2012

4.2.2.1 2005 Six-Year Review 2 Data Used 

As described in the Total Coliform Rule Compliance Monitoring Data Quality and 

Completion Report (USEPA, 2010e) (Data Quality Report) prepared during the TCRDSAC 

process prior to this EA, the 2005 Six-Year Review 2 data is based on coliform monitoring data 

voluntarily provided to EPA by 37 primacy agencies (35 states and 2 tribes). The data consist of 

over nine million TCR records collected between 1998 and 2005. The data elements include the 

following: 

 PWS information—system type, population, source water type. 

 Sampling types—routine, repeat, special, unknown. 

 Sampling locations—entry point to the distribution system, distribution system, and 

for repeat samples, original location, downstream, upstream, and other. 

 Methods—for testing for TC and E. coli.

 Monitoring results—presence/absence for TC, FC, and E. coli.

EPA prepared a tool that states using the SDWIS/State database system could use to 

easily extract data from their databases and submit it to EPA. The data extraction tool was a 

query that collected the data elements requested in the letter to the states. The states that used this 

extraction tool are categorized as Tier 1 states. States submitting data in formats not compatible 

with the EPA extraction tool are categorized as Tier 2 states. States that submitted incomplete or 

problematic data are categorized as Tier 3, and states that did not provide data are categorized as 

Tier 4 (e.g., California and Pennsylvania). The complete lists of states included in each of the 

Tiers 1–4 are provided in the Data Quality Report. 

EPA used 2005 data exclusively in developing this EA. This decision was made for 

several reasons: 

 The 2005 data, being the most recent in the Six-Year Review, were judged to be 

more representative of present conditions than the less recent data, especially in 

terms of the percent of TC records that were positive. 

 There were fewer data in the years before 2005, especially 2001 and earlier, and 

therefore data in earlier years were judged to be too sparse to be comparable with 

the 2005 data. The difference in the base of PWSs studied year-to-year might have 

introduced an unknown bias. 

 As noted earlier, the 2005 data had more records than other years, and enough to 

represent the full spectrum of PWSs within states that provided the data. 

 Using only a single year of data was beneficial in that it simplified the analysis to 

include a fairly static set of PWSs, and did not require interpretation of the meaning 

of differences in occurrence data observed across multiple years. Understanding 

these types of differences would involve analysis of changing environmental 
Economic Analysis for the Final RTCR 4-8 September 2012

factors, program participation and administration factors, and possibly other factors 

before the data could be used as a baseline in the model. Additionally, a full year 

(and not less) of observed data was required for consistency with the basic unit of 

time in occurrence estimates, which is one year; and a period of 12 consecutive 

months is assumed to capture seasonal variation normally experienced in water 

quality. 

 A single year of data would allow for use of a single database to store all the data 

for easier analysis. 

4.2.2.2 Data Cleaning of 2005 Six-Year Review 2 Data 

The Data Quality Report (USEPA, 2010e) describes how TCR monitoring data were 

obtained, evaluated, and modified where necessary to make the database internally consistent 

and usable for analysis. Exhibit 2.1 in the Data Quality Report provides a complete list of states 

or territories that submitted data and a description of the use of these data. 

To determine whether a PWS’s sampling data were complete in the 2005 Six-Year 

Review 2 dataset, a representative month for a system was defined as having at least 50 percent 

of the number of samples expected based on the size of system and 1989 TCR requirements. 

Using this 50 percent criterion, months that were not representative of a PWS were excluded; 

this cleaning resulted in a decrease of only 2 percent of submitted data, and is unlikely to have 

skewed occurrence results, as shown by Exhibits 3.1 and 3.2, respectively, of the Data Quality 

Report. EPA determined that a 50 percent criterion systematically eliminated systems that were 

only reporting positive results or otherwise not reporting many of its samples, while retaining 

data for systems that had increased from one size category to the next (and were therefore 

expected to have, for example, 15 samples per month instead of 10). The TCRDSAC agreed with 

this approach, which is explained further in Section 3.2 of the Data Quality Report. 

4.2.2.3 Representativeness of 2005 Six-Year Review 2 Data 

In the course of cleaning the 2005 Six-Year Review 2 data, EPA examined data from the 

10 largest PWSs in each state and found, by matching with SDWIS inventory information, that 

many larger systems were not included in the data submitted by the states. For the largest 

systems that are represented in the 2005 Six-Year Review 2 data, EPA also compared the 

expected number of samples based on population served (i.e., the 1989 TCR requires a system 

serving a million people to sample 300 times per month) to the number of samples in the actual 

data to evaluate completeness. In some cases it was found that only data from the state laboratory 

were included. Since many large PWSs have their own laboratory and do not use the state 

laboratories, data for these large systems were not available. In many cases, states handled large 

PWSs with negative samples in a special way, and those data were not captured by the data 

extraction tool. The end result was that large PWSs had a lower percentage of samples included 

in the data than did smaller systems; therefore, data for systems serving more than 4,100 were 

not used from this database. Instead, as described in Section 4.3.4.2, EPA used SDWIS/FED 

violations data to model changes in the number of corrective actions to be implemented and the 

net change in costs under the RTCR (i.e., incremental costs over the 1989 TCR) for PWSs 

serving greater than 4,100 people. 
Economic Analysis for the Final RTCR 4-9 September 2012

Based on the number of smaller PWSs (serving fewer than 4,101 people) in states whose 

data were excluded for data quality/quantity issues or for non-submittal of data, approximately 

39 percent of systems were excluded from the analysis. Specifically, the following states or 

territories submitted data but were excluded because of issues with the quality or quantity of data 

submitted: AL, American Somoa, DC, ME, MD, NJ, SC, SD, TN, and the Navajo Nation. 

Additionally, the following states/territories did not submit data: CA, Guam, HI, LA, MA, MS, 

Northern Mariana Islands, PA, Puerto Rico, TX, Virgin Islands, and WA. The remaining 70 

percent of PWSs’ data were used to simulate occurrence of TC and E. coli under the 1989 TCR, 

the RTCR and the Alternative option and to develop parameters for use in the RTCR predictive 

model, described in Chapter 5 of this EA. 

Although approximately 61 percent of the systems are represented in the analysis, only an 

estimated 32 percent of the population served by PWSs is represented due to the omission of 

some large population states (i.e., CA, PA, and TX).17 However, since EPA is not predicting 

changes in occurrence for the largest systems (i.e., the majority of the population is served by 

very large CWSs) the underrepresentation of population served in the data is not expected to 

have a significant impact on the analyses performed. 

4.2.3 Background on Other Data and Information Used 

SDWIS/FED data and 2005 Six-Year Review 2 data represent the largest portion of 

information used for the RTCR baseline analysis. In addition, EPA incorporated information 

from the GWR, the U.S. Census, and the 1989 TCR to develop assumptions for the model. EPA 

also relied upon the knowledge and experience of stakeholders representing industry, states, 

small systems, and the public to inform the process throughout development of the RTCR. 

4.2.3.1 1989 TCR 

Under the 1989 TCR, PWSs experienced reduced occurrence of fecal indicator 

contamination after the effective date as a result of increased sampling, reporting, and to some 

degree corrective actions. In recent years under the 1989 TCR, the occurrence of fecal indicators 

has reached a steady state, as reflected in SDWIS/FED violation data (see Section 4.3.4.2 for 

discussion). Additional reductions in occurrence are expected prior to RTCR implementation that 

reflect water quality improvements due to implementation of the GWR. Because the water 

quality data used in this analysis is the Six-Year Review 2 data for 2005, adjustments are made 

to the 2005 data in the modeling to reflect this GWR impact. Further reductions in occurrence of 

fecal indicators under the RTCR can then be properly modeled based on more focused 

assessments and corrective actions in response to TC+ or E. coli-positive (EC+) samples. 

4.2.3.2 GWR data 

The GWR was promulgated to address microbial contamination of ground water sources 

used to supply drinking water and, specifically, to address the concern about potential adverse 

health risks that may be associated with fecal contamination. Before the GWR was promulgated, 

 

17 As described further in the Data Quality Report, submission of the data was voluntary; CA, PA, and TX did not 

submit data. 
Economic Analysis for the Final RTCR 4-10 September 2012

there were no federal regulations to require filtration or disinfection of ground water sources to 

remove microbial contaminants. The GWR requirements include sanitary surveys, triggered 

monitoring in response to TCR samples testing positive for contaminant indicators, source water 

monitoring for indicators of fecal contamination such as E. coli,

18 and corrective actions that may 

include disinfection. 

Both the GWR and the RTCR seek to decrease the level of fecal contamination in 

drinking water. Since the RTCR applies to all PWSs including systems that use ground water 

sources, the implementation of the GWR (requiring compliance beginning December 1, 2009) in 

advance of the RTCR is expected to modify the TCR baseline (see Sections 4.3.1–4.3.2) taken 

from the 2007 SDWIS/FED (4th quarter) and 2005 Six Year Review data (see Sections 4.2.1 and 

4.2.2 for discussion of SDWIS/FED and 2005 Six Year Review data, respectively). The number 

of disinfecting and nondisinfecting public ground water systems prior to the start of GWR 

implementation (based on 4th quarter 2007 SDWIS/FED data) is 54,469 and 85,999, respectively. 

By October 2012 when the GWR is fully implemented, EPA predicts that the number of systems 

disinfecting will have increased from the 2007 4th quarter baseline. The RTCR occurrence model 

incorporates the estimated change in the number of systems with disinfection into this EA 

baseline (Section 5.3.1). 

The RTCR occurrence model (described in further detail in Section 5.3 of this EA) 

accounts for GWR implementation in the following ways: 

 The baseline number of disinfecting systems in the 4th quarter 2007 data of 

SDWIS/FED will be increased to account for the additional systems that are 

estimated to begin disinfecting under the GWR. 

 Sanitary surveys, as required by the GWR, will be phased in for applicable PWSs in 

the model (over five years for systems on a five year sanitary survey cycle; and over 

three years for systems on a three year cycle), resulting in reduced occurrence for 

these systems indefinitely to represent that systems are correcting deficiencies 

identified in the survey. Further detail on this component of the model is provided 

in Chapter 5 of this EA. 

 GWR compliance monitoring will be incorporated with an additional decrease in 

probability of occurrence to represent anticipated efforts by systems to identify and 

correct problems. 

 The baseline estimates will account for the decreased levels of TC occurrence and 

fecal contamination achieved under the GWR. This decrease will be reflected in 

model output for the following RTCR rule components: 

– Repeat monitoring 

– Additional routine monitoring 

– Triggers for level 1 and 2 assessments 

 

18 Standridge, J. (2008) discusses the use of E. coli as an indicator of drinking water quality. 
Economic Analysis for the Final RTCR 4-11 September 2012

– Corrective actions 

– Public notification 

 Under the GWR, if a PWS experiences a TC+ while conducting TCR monitoring, 

the system must sample the source water for the presence of a fecal indicator (E. 

coli, enterococci, or coliphage, as determined by the state). GW systems that have a 

positive initial fecal indicator sample from the source are required to take five 

repeat fecal indicator samples if they are not required by the state to take corrective 

action. Under the RTCR, PWSs having less than 4-log treatment and serving 1,000 

people or fewer would only be required to take 3 repeat samples. To meet GWR 

requirements, these systems would need to take one additional sample at the source. 

 Under the RTCR, PWSs having less than 4-log treatment and serving 1,000 people 

or fewer would be required to take 3 repeat samples after a TC+ routine sample as 

opposed to the 4 repeat samples required under the 1989 TCR. To meet GWR 

requirements, these systems would need to take one additional sample (i.e., a fourth 

repeat sample) at the source. Under the RTCR, the PWS may, with written state 

approval, take one of its repeat RTCR samples at the location required for triggered 

source water monitoring under the GWR if the PWS demonstrates that the repeat 

sample sites in the sample siting plan remain representative of water quality in the 

distribution system. 

4.2.3.3 U.S. Census Data 

The baseline analysis incorporates data from the U.S. Census that are publically available 

and include surveys of the U.S. population, economics, industry, and geography. Census 2000 

data were used in the baseline analyses to estimate the sensitive subpopulations in the U.S. who 

may be more susceptible to illness as a result of poor drinking water quality, as explained in 

Section 4.4 of this EA. Additionally, the Census 2008 Annual Social and Economic Supplement 

was used in the estimates of household size as described in Section 4.3.3. 

4.3 Baseline Profile

The RTCR applies to all PWSs, regardless of their size, water source (GW or SW), or 

type (CWS, NTNCWS, or TNCWS). This section estimates the baseline number of PWSs and 

the size of the population subject to the RTCR in each of these subcategories. EPA used 4th

quarter 2007 data from SDWIS to develop this inventory baseline because at the time when the 

TCRDSAC began discussing the RTCR and its analysis, 2007 data were the most recent 

inventory data available. As described in Section 4.2, the best available occurrence data for 

smaller PWSs were collected in 2005. For larger systems (serving >4,100 people) as Section 

4.3.4.2 describes, EPA used SDWIS/FED violations data for modeling benefits and costs for 

PWSs serving more than 4,100 people because the 2005 Six-Year Review 2 dataset (containing 

sampling data) for larger systems was not as robust. Third quarter 2005 SDWIS/FED data is used 

for the violation baseline since EPA compiles violation data in the 3rd quarter every year (as 

opposed to the 4th quarter freeze used for annual compilation inventory data) and was the most 

recently available data at the time that this analysis was begun. Use of the 2005 data was deemed 
Economic Analysis for the Final RTCR 4-12 September 2012

to be equivalent to an average of multiple years due to the steady numbers of violations seen in 

the data over the past several years. 

The baseline described in the following sections is used as a reference point for informing 

net costs and benefits as described in Chapters 6 and 7 of this EA. 

4.3.1 Pre-GWR Baseline 

Estimates of the number of GW systems subject to the RTCR are presented in Exhibit 4.1 

below. These numbers reflect SDWIS/FED inventory from the fourth quarter of 2007, prior to 

implementation of the GWR. Ground water system inventories indicate disinfection status as 

disinfecting or unreported; since reporting is voluntary, the status of a system that did not report 

disinfection is actually unknown, although EPA assumes in this EA that the system is not 

disinfecting. The number of disinfecting PWSs includes those achieving less than 4-log 

disinfection, which matches the categorization of systems used to estimate the underlying 

distributions of occurrence of TC and E. coli modeled, as described in Chapter 5. 

Exhibit 4.2 presents the number of SW systems subject to the RTCR, also derived from 

the SDWIS/FED database. GWR implementation does not affect the disinfection status of SW 

systems. 

Exhibit 4.3 presents the population associated with each PWS category of system size 

and type prior to incorporating the effects of the GWR into the model; this is the pre-GWR 

baseline affected population. After incorporating GWR effects, some systems shift into the 

disinfecting category and some of the population shifts accordingly. 

Lastly, Exhibit 4.4 presents the distribution of PWSs by frequency of sampling—

monthly, quarterly, or annually—under the 1989 TCR for those systems that qualify for reduced 

monitoring (all other systems are required to sample monthly). This is the baseline distribution of 

sampling frequencies used for analyses in this EA. This distribution was derived as part of the 

work done by the Technical Workgroup (TWG) supporting the TCRDSAC, and validated by the 

Association of State Drinking Water Administrators (ASDWA). Workgroup members analyzed 

2005 Six Year Review and other readily available state data to derive the estimates shown in 

Exhibit 4.4. 
Economic Analysis for the Final RTCR 4-13 September 2012

Exhibit 4.1 Pre-GWR Baseline Number of GW Systems 

Disinfecting Non-Disinfecting Disinfecting Non-Disinfecting Disinfecting Non-Disinfecting 

<100 6,132 5,806 2,907 5,919 13,558 46,642

101-500 9,260 4,632 2,753 3,860 5,341 13,934

501-1,000 3,502 965 868 850 673 1,290

1,001-4,100 5,405 1,038 542 270 269 348

4,101-33,000 2,798 358 56 14 27 40

33,001-96,000 307 28 2 - - 2

96,001-500,000 62 1 - - - 1

500,001-1 Million 4 - - - - 1

> 1 Million 3 - - - - -

Total 27,473 12,828 7,128 10,913 19,868 62,258

Combined Total 

CWS NTNCWS TNCWS

40,301 18,041

Source: Data extracted from SDWIS/FED PWS Inventory, 2007 4th Quarter Data based on listed disinfection status.

PWSs listed as "unknown” disinfection status in SDWIS/FED are counted as non-disinfecting.

82,126

Number of GW PWSs (Pre-GWR)

PWS Size

Exhibit 4.2 Baseline Number of SW Systems 

CWS NTNCWS TNCWS

<100 1,170 250 1,339

101-500 2,150 253 497

501-1,000 1,173 88 88

1,001-4,100 2,938 72 67

4,101-33,000 3,164 22 18

33,001-96,000 720 2 -

96,001-500,000 308 1 -

500,001-1 Million 31 - -

> 1 Million 17 - 1

Total 11,671 688 2,010

PWS Size Number of SW PWSs

Source: Data extracted from SDWIS/FED PWS Inventory, 2007 4th Quarter 

Data. SW count includes GWUDI systems. 

 

 
Economic Analysis for the Final RTCR 4-14 September 2012

Exhibit 4.3 Pre-GWR Baseline Population Served by GW Systems 

Disinfecting Non-Disinfecting Disinfecting Non-Disinfecting Disinfecting Non-Disinfecting 

<100 387,558 342,243 168,482 326,342 645,949 2,139,529

101-500 2,375,507 1,085,555 708,424 948,500 1,231,077 3,005,703

501-1,000 2,570,662 703,562 630,071 600,643 516,707 956,781

1,001-4,100 11,307,740 2,074,139 991,971 456,985 449,757 599,171

4,101-33,000 29,346,057 3,627,365 418,368 122,865 194,136 353,290

33,001-96,000 15,587,186 1,527,861 89,405 - - 119,700

96,001-500,000 9,935,500 107,323 - - - 100,000

500,001-1 Million 2,670,841 - - - - 725,000

> 1 Million 4,389,948 - - - - -

Total 78,570,999 9,468,048 3,006,721 2,455,335 3,037,626 7,999,174

Combined Total 

CWS NTNCWS TNCWS

88,039,047 5,462,056

Source: Data extracted from SDWIS/FED PWS Inventory, 2007 4th Quarter Data based on listed disinfection status.

Populations for PWSs listed as “unknown” disinfection status in SDWIS/FED are counted as non-disinfecting.

11,036,800

PWS Size

Population Served by GW PWSs (Pre-GWR)
Economic Analysis for the Final RTCR 4-15 September 2012

Exhibit 4.4 Percent Distribution of GW System Monitoring Frequencies by PWS 

Size and Type for 1989 TCR 

Size

 Number of 

Systems Monthly Quarterly Annual

≤100 6,132 86.6% 13.4% 0.0%

101-1000 12,762 88.5% 11.5% 0.0%

1001-4100 5,405 100.0% 0.0% 0.0%

≤100 5,806 86.6% 13.4% 0.0%

101-1000 5,597 88.6% 11.4% 0.0%

1001-4100 1,038 100.0% 0.0% 0.0%

≤100 2,904 19.3% 64.7% 16.0%

101-1000 3,621 18.5% 66.7% 14.7%

1001-4100 542 100.0% 0.0% 0.0%

≤100 5,913 19.3% 64.7% 16.0%

101-1000 4,710 18.5% 66.7% 14.8%

1001-4100 270 100.0% 0.0% 0.0%

≤100 13,558 4.8% 62.9% 32.3%

101-1000 6,014 7.9% 66.9% 25.2%

1001-4100 269 100.0% 0.0% 0.0%

≤100 46,642 4.8% 62.9% 32.3%

101-1000 15,224 7.8% 66.8% 25.3%

1001-4100 348 100.0% 0.0% 0.0%

Transient, Noncommunity Water Systems (TNCWSs), Non-Disinfecting

Source: Based on EPA and TWG analysis of 2005 Six-Year data and individual state 

statutes during the TCRDSAC and review by ASDWA. 

Note: All other system sizes and types are required to sample monthly. 

Community Water Systems (CWSs), Disinfecting

Community Water Systems (CWSs), Non-Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Non-Disinfecting

Transient, Noncommunity Water Systems (TNCWSs), Disinfecting

4.3.2 Post-GWR Baseline 

PWSs must comply with requirements of the GWR beginning December 1, 2009, which 

will be approximately five years prior to the effective date of the RTCR. To account for the 

impact of the GWR on baseline occurrence for those PWSs using a GW source, EPA performed 

a number of adjustments to the 2005 data prior to its use in this EA. 

Using 2007 SDWIS inventory data (as explained in Section 4.3.1) as a pre-GWR 

inventory baseline, EPA applied probabilities of Psample and Pwell

19 to determine the probability of 

a positive sample for a fecal indicator in nondisinfecting PWSs. A fraction of those systems with 

 

19 The term “Pwell” refers to the probability that a randomly selected well across the United States will ever test 

positive in its source water for a virus or indicator species, such as TC; “Psample” is the probability that given a 

contaminated well, a random sample at the well will test positive for a virus or indicator. The GWR EA (November 

2006) (USEPA, 2006a), and in particular the Baseline Chapter of that document, provides a detailed explanation of 

the analysis used to generate these Pwell and Psample estimates. 
Economic Analysis for the Final RTCR 4-16 September 2012

a positive sample is expected to move to a disinfecting status in the five years prior to RTCR 

implementation. This modification ensured that systems in the analysis that disinfect drew from 

the probability distribution for TC+ and EC+ for disinfecting systems, which is different from 

the distribution for those that do not disinfect. The model continues to apply Pwell and Psample

throughout the RTCR period of analysis (the 25 years following promulgation). The application 

of this model parameter, as it is applied in the context of other aspects of the predictive 

occurrence model, is explained in further detail in Chapter 5 of this EA. Exhibit 4.5 shows the 

baseline inventory of GW systems by disinfection status in model year 5, which is the year 

immediately prior to the effective date of the RTCR. The estimates in Exhibit 4.5 of 

nondisinfecting PWSs include a number of systems that selected a corrective action other than 

converting to a disinfecting system in response to fecal contamination at the source. 

As explained in Chapter 5 of this EA, a number of PWSs will undertake sanitary surveys 

(for all GW systems) and compliance monitoring (for disinfecting GW systems) prior to 

implementation of the RTCR; although the costs are not considered in this EA (they were 

considered in the GWR EA), the systems are assigned a reduced occurrence, which is reflected 

in the RTCR baseline. The predictive model incorporates the contribution of sanitary survey 

results to the qualification of systems for reduced monitoring by assuming a 10 percent reduction 

in the number of systems finding a TC+, which is applied to a portion of systems each year and 

retained throughout the period of analysis. For NCWSs, the reduction is applied to one-fifth of 

systems per year for the five years of GWR implementation prior to the RTCR effective date; for 

CWSs, it is applied to one-third of systems in each of the first three years of the GWR 

implementation period. Similarly, the system incorporates the effect of compliance monitoring 

by disinfecting GW systems by applying an additional 10 percent reduction for systems that are 

disinfecting as of the RTCR effective date, and additionally to those determined in the model to 

select disinfection as a corrective action; the compliance monitoring reduction in occurrence is 

assumed to apply in all remaining years of the analysis once a system qualifies for the reduction. 

As described in Section 5.3.2.2 of this EA, model output was generated for a 30-year 

period to encompass 5 years of the effects of GWR implementation and 25 years of the effects of 

RTCR implementation. Chapter 5 presents this output for the 30-year period. For the purpose of 

the benefit-cost analysis, years 3 through 27 of this period are included in the calculations and 

presented in the results shown in Chapter 6 (Benefits Analysis), Chapter 7 (Cost Analysis), and 

Chapter 9 (Comparison of Benefits and Costs). Initially in the modeled period, all systems under 

the 1989 TCR and the RTCR are assumed to sample based on the sampling regimen applicable 

to their system type, size, type of water source, and whether or not the system disinfects (Exhibit 

4.4).20 Under the Alternative option, all systems are assumed to sample monthly for the first five 

years after the RTCR effective date. Following an assessment period as described in Section 

5.3.2.2, monitoring frequencies are adjusted from the baseline for GW systems serving fewer 

than 1,000 people. All other systems remain on monthly monitoring. 

The estimates for distribution of PWSs across the M/Q/A monitoring schedules as 

adjusted from the baseline distribution are presented in Chapter 5 for the 1989 TCR, RTCR, and 

Alternative option (Exhibits 5.9a–5.9c). 

 

20 Based on EPA and TWG analysis of Six-Year data and individual state statutes during the TCRDSAC and review 

by ASDWA. 
Economic Analysis for the Final RTCR 4-17 September 2012

Exhibit 4.5 Baseline Number of GW Systems Post-Implementation of the GWR 

(Model Year 5) 

Disinfecting Non-Disinfecting Disinfecting Non-Disinfecting Disinfecting Non-Disinfecting 

≤100 6,190 5,748 2,938 5,888 13,753 46,447

101 - 500 9,311 4,581 2,776 3,837 5,451 13,824

501-1,000 3,512 955 873 845 684 1,279

1,001-4,100 5,422 1,021 547 265 274 343

4,101-33,000 2,798 358 56 14 27 40

33,001-96,000 307 28 2 - - 2

96,001-500,000 62 1 - - - 1

500,001-1 Million 4 - - - - 1

> 1 Million 3 - - - - -

Total 27,610 12,691 7,191 10,850 20,189 61,937

Combined Total 

PWS Size

Number of GW PWSs (Post-GWR)

CWS NTNCWS TNCWS

40,301 18,041 82,126

Source: Estimates calculated based on the proportion of PWSs changing disinfection status, which is an output from the predictive occurrence 

model, as described in Chapter 5 of this EA.

4.3.3 Baseline Population Served 

PWS population characteristics are important to this analysis for determining the number 

of people, both prior to and following implementation of the GWR, for which risk changes under 

each component of the RTCR, as discussed in Chapter 6 of this EA. These population estimates 

are based on SDWIS/FED 2007 4th quarter data as described in Section 4.2.1, and stratified by 

PWS size, type, whether the system disinfects or not and whether the system uses GW or SW 

sources. The estimates represent the number of systems which disinfect water and their 

populations served; both estimates are adjusted upward based on predicted impacts of the GWR 

in the five years prior to the effective date of RTCR requirements, as shown in Exhibits 4.6 and 

4.7 below. (See Exhibits 4.1 and 4.3 for PWS counts and population served by disinfection status 

prior to effects of GWR.) 
Economic Analysis for the Final RTCR 4-18 September 2012

Exhibit 4.6 Baseline Population Served by GW Systems Post-Implementation of 

the GWR (Model Year 5) 

Disinfecting Non-Disinfecting Disinfecting Non-Disinfecting Disinfecting Non-Disinfecting 

≤100 390,986 338,815 170,177 324,647 654,897 2,130,581

101 - 500 2,387,462 1,073,600 713,960 942,964 1,254,805 2,981,975

501-1,000 2,578,316 695,908 633,744 596,970 524,599 948,889

1,001-4,100 11,341,403 2,040,476 999,913 449,043 458,242 590,686

4,101-33,000 29,346,057 3,627,365 418,368 122,865 194,136 353,290

33,001-96,000 15,587,186 1,527,861 89,405 - - 119,700

96,001-500,000 9,935,500 107,323 - - - 100,000

500,001-1 Million 2,670,841 - - - - 725,000

> 1 Million 4,389,948 - - - - -

Total 78,627,698 9,411,349 3,025,567 2,436,489 3,086,679 7,950,121

Combined Total 

PWS Size

Population Served by Post-GWR PWSs

CWS NTNCWS TNCWS

88,039,047 5,462,056 11,036,800

Note:

Estimates calculated based on the proportion of PWSs changing disinfection status, which is an output from the predictive 

occurrence model, as described in Chapter 5 of this EA. 

Exhibit 4.7 Baseline Population Served by SW Systems 

CWS NTNCWS TNCWS

<100 56,740 13,297 57,454

101-500 608,084 68,083 116,529

501-1,000 885,400 67,958 70,147

1,001-4,100 6,628,597 140,168 143,347

4,101-33,000 38,700,554 174,408 147,423

33,001-96,000 39,034,554 121,446 -

96,001-500,000 58,489,936 203,000 -

500,001-1 Million 22,327,506 - -

> 1 Million 37,363,275 2,000,000 - 

Total 204,094,646 788,360 2,534,900

PWS Size Population Served by SW PWSs

Source: Data extracted from SDWIS/FED PWS Inventory, 2007 4th Quarter Data. 

Population figures for SW systems include GWUDI systems.

Number of Households Served 

Because PWS costs are often passed onto customers in the form of water rate increases, 

the RTCR EA also includes analyses to assess the impact of the rule provisions at a household 

level. The number of households served by CWSs expected to be subject to the RTCR is 

estimated by dividing the population for each PWS size category (Exhibits 4.6 and 4.7 above) by 

the average number of people per household, which was estimated as 2.56 for the year 2007 
Economic Analysis for the Final RTCR 4-19 September 2012

(U.S. Census Bureau, 2008). Exhibit 4.8 below shows the number of households served by 

ground water and surface water systems, respectively. 

Exhibit 4.8 Household Baseline 

SW CWSs

Disinfecting Non-Disinfecting Disinfecting

<100 151,390 133,689 22,164

101-500 927,932 424,045 237,533

501-1,000 1,004,165 274,829 345,859

1,001-4,100 4,417,086 810,211 2,589,296

4,101-33,000 11,463,304 1,416,939 15,117,404

33,001-96,000 6,088,745 596,821 15,247,873

96,001-500,000 3,881,055 41,923 22,847,631

500,001-1 Million 1,043,297 - 8,721,682

> 1 Million 1,714,823 14,595,029 - 

Total 30,691,796 3,698,456 79,724,471

GW CWSs

Number of Households

PWS Size

Sources: U.S. Census Bureau, Current Population Survey, 2008 Annual Social and 

Economic Supplement; SDWIS/FED PWS Inventory, 2007 4th Quarter Data.

4.3.4 Baseline Water Quality 

The following sections provide an overview of summary statistics relating to baseline 

water quality. The source data from which these summary statistics are derived form the basis of 

further analysis in the RTCR occurrence and risk assessment models as described in later 

chapters of the EA. 

4.3.4.1 Percent of TC and EC-Positive Samples Based on 2005 Six-Year Review 2 Data 

Exhibit 4.9 below shows the percent of TC+ and EC+, samples based on PWS type and 

size. As described in Section 4.2.2.2, the 2005 Six-Year Review 2 data was cleaned using a 

criterion that a given system-month of data should include a minimum of 50 percent of the 

expected number of samples based on the system’s population served and water system category. 

The “TC+ samples” column was calculated by taking the total number of routine TC+ 

samples and dividing by the number of routine TC samples. For small PWSs, additional routine 

TC samples in the month following a TC+ were included in the denominator. To calculate the 

EC+ rate, the total number of EC+ samples was divided by the total number of TC- samples21

plus the number of TC+ samples that were tested for E. coli. This EC+ computation did not 

include additional routine samples taken in the month following a TC+ because a significant 

 

21 EPA assumes that a PWS will not test for EC if the TC assay is negative. 
Economic Analysis for the Final RTCR 4-20 September 2012

number of PWSs did not provide data on EC+ or E. coli-negative samples, and some systems 

tested for FC and not E. coli. 
Economic Analysis for the Final RTCR 4-21 September 2012

Exhibit 4.9 Total Coliform and E. coli Percent Positive by System Size and Type 

PWS

Type

Source

Water

Population

Served

 TC

(# Samples) 

 TC

(+ Samples) 

TC

(% Positive)

EC

(# Samples) 1

 EC

(+ Samples) 

EC

(% Positive)2

≤100 93,105 2,479 2.66% 1,172 72 0.08%

101 - 500 125,490 2,500 1.99% 1,639 61 0.05%

501-1,000 48,265 736 1.52% 483 20 0.04%

1,001-4,100 110,391 1,176 1.07% 732 21 0.02%

4,101-33,000 183,721 877 0.48% 458 22 0.01%

33,001-100,000 96,361 214 0.22% 44 2 0.00%

>100,000 64,965 289 0.44% 34 1 0.00%

Total GW 722,298 8,271 1.15% 4,562 199 0.03%

≤100 6,735 95 1.41% 64 6 0.09%

101 - 500 19,716 227 1.15% 159 10 0.05%

501-1,000 12,828 90 0.70% 70 7 0.05%

1,001-4,100 55,310 314 0.57% 233 17 0.03%

4,101-33,000 175,758 525 0.30% 399 41 0.02%

33,001-100,000 112,894 157 0.14% 106 5 0.00%

>100,000 112,143 235 0.21% 99 2 0.00%

Total SW 495,384 1,643 0.33% 1,130 88 0.02%

GW & SW Total CWS 1,217,682 9,914 0.81% 5,692 287 0.02%

≤100 163,730 7,820 4.78% 5,820 316 0.20%

101 - 500 52,891 2,418 4.57% 1,869 99 0.19%

501-1,000 6,952 299 4.30% 217 4 0.06%

>1,000 7,062 143 2.02% 85 2 0.03%

Total GW 230,635 10,680 4.63% 7,991 421 0.18%

≤100 6,723 150 2.23% 141 17 0.25%

101 - 500 2,854 75 2.63% 69 13 0.46%

501-1,000 523 19 3.63% 19 - 0.00%

>1,000 988 6 0.61% 37 - 0.00%

Total SW 11,088 250 2.25% 266 30 0.27%

GW & SW Total TNCWS 241,723 10,930 4.52% 8,257 451 0.19%

≤100 46,505 1,476 3.17% 1,061 34 0.07%

101 - 500 33,084 893 2.70% 628 19 0.06%

501-1,000 9,531 166 1.74% 103 2 0.02%

>1,000 13,138 177 1.35% 103 5 0.04%

Total GW 102,258 2,712 2.65% 1,895 60 0.06%

≤100 1,668 32 1.92% 30 4 0.24%

101 - 500 2,304 9 0.39% 9 2 0.09%

501-1,000 932 6 0.64% 5 - 0.00%

>1,000 1,316 1 0.08% 1 - 0.00%

Total SW 6,220 48 0.77% 45 6 0.10%

GW & SW Total NTNCWS 108,478 2,760 2.54% 1,940 66 0.06%

S W

TNCWS

GW

S W

Source: Derived using 2005 Six-Year Review 2 Data, which was filtered by including a month of data for a given system (system-month) 

only if it represented at least 50% of the expected number of samples for a month based on the system’s size. The Total Coliform Rule 

Compliance Monitoring Data Quality and Completion Report (USEPA, 2010e) includes a detailed description of this data cleaning 

process.

Notes: 

1) Number of samples that were specifically tested for E. coli . The denominator of the E. coli percent positive calculation includes this 

number plus the number of total coliform negative samples (TC #samples – TC +samples).

2) Percent EC+ was calculated as (# EC+ samples)/(# EC samples).

NTNCWS

GW

S W

CWS

GW
Economic Analysis for the Final RTCR 4-22 September 2012

4.3.4.2 Violation Levels Based on SDWIS/FED Data 

Non-acute violations are triggered under the 1989 TCR by water quality violations. They 

are defined as >1 routine or repeat monitoring sample testing positive for TC in a given 

compliance period (month, quarter, or year) for PWSs serving fewer than 33,001 people, or by 

>5.0 percent of samples being positive for systems taking >40 samples per month (typically 

those systems serving greater than 33,000 people). Acute violations are triggered when any PWS 

has a repeat sample with an EC+ or FC-positive (FC+) or has an FC+ or EC+ routine sample 

followed by a TC+ repeat sample in a given month. 

Exhibit 4.10 below presents an assessment of water quality prior to the RTCR 

promulgation in terms of the number of acute and non-acute violations incurred by PWSs. The 

number of violations from this data is directly input into the cost model for PWSs serving more 

than 4,100 people to derive estimates of the number of assessments and corrective actions that 

will be undertaken under the RTCR. As noted in Exhibit 4.10, the data used is from 2005 3rd

quarter. Exhibit 4.11 presents the seven years of PWS violation data22 evaluated by the TWG. 

Appendix G presents further detail on this assessment, including queries used in SDWIS/FED 

and the resulting datasets downloaded. 

In addition to the acute and non-acute system violation data, Exhibit 4.11 also presents 

data on the numbers of PWSs with monitoring and reporting violations (minor and major for 

routine and repeat monitoring and reporting). Although PWS monitoring and reporting violation 

data is not used directly in the quantitative analyses performed for the EA, the TCRDSAC did 

consider the data in its deliberations on the impact of the regulation. In particular, the TCRDSAC 

determined that the revisions to the RTCR may significantly reduce the high numbers of 

monitoring and reporting violations by: a) reducing the numbers of additional routine and repeat 

samples required; b) providing more flexibility in development of sampling site plans; and c) 

adding consequences for missed monitoring (possible triggering to increased monitoring for 

missed samples). 

The data verification process was used to review individual states’ data in comparison to 

SDWIS/FED data and to compare violations rates across states. This process revealed many 

differences between states in their implementation of the 1989 TCR, and allowed EPA to 

identify and review outliers in the national database. Specifically, EPA did not include violation 

data from Ohio, U.S. territories, or tribal PWSs in the summaries presented in Exhibits 4.10 and 

4.11. Review of the data verification information revealed that Ohio’s broad interpretation of 

what constitutes a violation led to abnormally high violation counts compared (on average) to 

other states. For U.S. territories and tribal systems, it was established that unique environmental 

factors and operating conditions contribute to abnormally high TC+ results and associated 

violations. Thus, inclusion of these results would skew the national averages used for analysis, 

and were therefore excluded. 

 

22 Exhibit 4.11 presents PWS counts (PWSs with at least one violation during the year) to be consistent with the 

metric evaluated by the TCRDSAC TWG. Exhibit 4.10 presents total violation counts, which are used as inputs to 

the predictive modeling for the EA. 
Economic Analysis for the Final RTCR 4-23 September 2012

Exhibit 4.10 Baseline Number of 1989 TCR Violations by System Size and Type 

(2005) 

Non-Acute Acute Non-Acute Acute

A B C D E F

CWSs

≤100 905 52 16 3 11,709 1,133

101-500 809 34 50 7 13,508 2,067

501-1,000 203 13 16 3 4,299 1,112

1,001-3,300 272 8 55 7 5,490 2,406

3,301-10,000 171 8 75 3 2,628 2,015

10,001-50,000 125 8 78 4 1,247 1,752

50,001-100,000 11 2 5 4 147 362

100,001-250,000 1 1 3 1

250,001-500,000 - - - -

500,001-1 Million - - 1 -

> 1 Million - - - - 3 15

Total CWSs 2,497 126 299 32 39,092 11,168

NTNCWSs

≤100 514 34 7 2 8,392 249

101-500 346 20 4 - 6,294 246

501-1,000 57 6 2 - 1,622 87

1,001-3,300 58 4 - - 726 66

3,301-10,000 9 2 1 - 102 23

10,001-50,000 1 - - - 11 4

50,001-100,000 - - - - - 1

100,001-250,000 - - - - -

250,001-500,000 - - - - -

500,001-1 Million - - - - -

> 1 Million - - - - - -

Total NTNCWSs 985 66 14 2 17,147 677

TNCWSs

≤100 2,665 278 19 5 58,396 1,334

101-500 833 76 11 1 18,184 492

501-1,000 133 11 4 - 1,868 85

1,001-3,300 58 2 1 - 578 57

3,301-10,000 5 - 1 - 77 22

10,001-50,000 - - - - 11 3

50,001-100,000 - - - - 3 -

100,001-250,000 - - - -

250,001-500,000 - - - -

500,001-1 Million - - - -

> 1 Million - - - - - 1

Total TNCWSs 3,694 367 36 6 79,118 1,994

 1 -

 61 306

Number of Violations in 

GW PWSs

Number of Violations in 

SW PWSs

Total Number of 

GW PWSs 

(without OH & PR)

Total Number of 

SW PWSs 

(without OH & PR)

 1

Sources:

(A) - (D) Acute/Non-Acute Violations from SDWIS/FED annual data for period ending 3rd quarter 2001 – 2007 (only 2005 data is 

presented in this exhibit). OH, U.S. territories, tribal PWS data excluded.

(E), (F) 2007 4th Quarter SDWIS Data, Total Number of PWSs.
Economic Analysis for the Final RTCR 4-24 September 2012

Exhibit 4.11 Number of PWSs with Violations by System Type (2001–2007) 

2001 2002 2003 2004 2005 2006 2007

CWS 143 144 185 171 151 171 171

NTNCWS 51 53 70 58 65 68 45

TNCWS 261 278 322 351 349 361 295

All 455 475 577 580 565 600 511

CWS 2,074 2,110 2,204 2,314 2,196 2,095 1,996

NTNCWS 601 679 725 750 753 735 655

TNCWS 2,707 2,934 3,036 3,132 3,039 3,244 3,209

All 5,382 5,723 5,965 6,196 5,988 6,074 5,860

CWS 3,312 3,327 3,900 3,924 3,760 3,659 3,415

NTNCWS 1,503 1,561 1,676 1,679 1,588 1,468 1,377

TNCWS 10,360 10,531 11,230 11,043 10,426 10,630 10,389

All 15,175 15,419 16,806 16,646 15,774 15,757 15,181

CWS 1,218 1,257 1,389 1,445 1,302 1,285 1,244

NTNCWS 187 182 200 233 194 214 183

TNCWS 701 842 883 903 875 843 839

All 2,106 2,281 2,472 2,581 2,371 2,342 2,266

PWS Type

Year

Acute MCL Violations

Non-Acute MCL Violations

Major Monitoring and Reporting Violations (Routine and Repeat) 

Minor Monitoring and Reporting Violations (Routine and Repeat)

Note: PWSs counts are of systems that had at least one violation during the year.

Source: SDWIS/FED annual data for period ending 3rd quarter 2001 – 2007. OH, U.S. territories, tribal PWS 

data excluded. 

4.4 Sensitive Sub-Populations 

Under the 1996 Amendments to the Safe Drinking Water Act (SDWA) (PL 104-182), 

EPA must analyze health impacts of rulemaking on sensitive subpopulations. Sensitive 

populations include “infants, children, pregnant women, the elderly, individuals with a history of 

serious illness, and other subpopulations that are identified as likely to be at a greater risk of 

adverse health effects due to exposure to contaminants in drinking water than the general 

population.” (1996 Amendments to the Safe Drinking Water Act).

Exhibit 4.12 presents EPA’s estimates of the number of U.S. individuals who are at 

increased risk of developing more severe symptoms from illnesses caused by waterborne 

pathogens. Persons suffering from certain diseases and/or conditions are believed to be sensitive 

to microbes and chemicals in drinking water. These subgroups of the population include 

pregnant women, the very young, the elderly, and the immunocompromised. In total, these 

subgroups represent approximately 20 percent of the current population of the U.S. 
Economic Analysis for the Final RTCR 4-25 September 2012

Exhibit 4.12 Estimates of Sensitive Subpopulations in the United States 

Sensitive 

Population Individuals

Approximate 

Percent of 

U.S. 

Population1 Citation/Notes

Pregnant women and neonates

Pregnant Women 6,240,000 2.2 Vital and Health Statistics, CDC (Ventura et 

al., 2000)

Neonates (under one 

month)2 317,137 0.1 U.S. 2000 Census (US Census Bureau, 2001a)

Age-based sensitive populations

Children (<5 years 

old) 19,175,798 6.8 U.S. 2000 Census (US Census Bureau, 2001a)

Elderly (>65 years 

old) 34,991,753 12.4 U.S. 2000 Census (US Census Bureau, 2001a)

Compromised immune status

Bone marrow 

transplant Recipients 20,000 0.01

National Marrow Donor Program

http://.marrow.org/MEDIA/facts_figures.pdf

AIDS Patients 816,149 0.3 HIV/AIDS Surveillance Report, cases 

through 2001 (CDC, 2002)

Organ transplant 

recipients 23,143 0.01 U.S. Census Bureau, Statistical Abstract of the U.S., based on 1998 data (2001b)

Total 61,583,980 21.8

 1 Based on U.S. Census estimate (July 2000). 

2 1/12 of the 2000 census population for age <1 year. 

4.5 Summary of Baseline Assumptions 

In Section 4.2 (Data Sources), EPA discusses the representativeness and quality of the 

data used from the 2005 Six-Year Review 2 data and SDWIS/FED. An additional source of 

uncertainty is introduced into the baseline in the monitoring frequencies estimated for systems, 

shown in Exhibit 4.4. As described in that section, to arrive at this distribution EPA and the 

Technical Workgroup conducted an analysis of 2005 Six-Year Data and individual state statutes, 

and had the results validated by ASDWA during the TCRDSAC deliberations. 

Exhibit 4.13 below presents a summary of the assumptions made in developing the 

RTCR EA baseline. These assumptions may introduce uncertainty into the predictive model and 

its outcomes in terms of benefits and costs. However, all of the assumptions influencing the EA 

baseline (1989 TCR) do so in the same way as for the RTCR and Alternative option. Therefore, 

EPA does not expect the net results of the analyses presented in this EA to be significantly 

influenced by the uncertainty in the assumptions applied in developing the RTCR EA baseline. 
Economic Analysis for the Final RTCR 4-26 September 2012

Exhibit 4.13 Summary of Baseline Assumptions Influencing RTCR Estimates

Uncertainty 

Factor

Current 

Assumption

Section 

with Full 

Discussion

Contributes 

Variability, 

Uncertainty, 

or 

Constant?

Most Likely Effect on Benefits1 Most Likely Effect on Costs1

Underestimate Overestimate Unknown 

Impact Underestimate Overestimate Unknown Impact

Pre-GWR 

baseline 

distribution of 

systems 

across 

sampling 

frequency 

categories 

(M/Q/A)

Varies per 

system 

category as 

shown in Ex.

4.4

4.3.1 Variability,

Uncertainty

No No X No No X

Selection of 

2005 data from 

Six Year 

Review 2 for 

use as 

baseline 

Data are 

adequately 

representative 

of U.S. PWSs 

and of sufficient 

quality.2

4.2.2 Variability, 

Uncertainty

No No X No No X

Use of 

SDWIS/FED 

for inventory 

data (2007 Q3) 

and violations 

data (2001–

2007 Q3)

Data are 

adequately 

representative 

of U.S. PWSs 

and of sufficient 

quality.

4.2.1 Variability, 

Uncertainty

No No X No No X

Distribution of 

systems 

across 

sampling 

frequency 

categories 

(M/Q/A) 

following 

Varies per 

system 

category as 

shown in Ex. 

5.9a

5.3.2.2 Variability,

Uncertainty

No No X No No X
Economic Analysis for the Final RTCR 4-27 September 2012

Uncertainty 

Factor

Current 

Assumption

Section 

with Full 

Discussion

Contributes 

Variability, 

Uncertainty, 

or 

Constant?

Most Likely Effect on Benefits1 Most Likely Effect on Costs1

Underestimate Overestimate Unknown 

Impact Underestimate Overestimate Unknown Impact

implementation 

of GWR 

sanitary 

surveys prior 

to RTCR 

implementation

Pwell—the 

portion of GW 

Systems

having viral 

pathogens in 

their source 

waters 

(adopted from 

GWR EA)

21.58 percent 5.3.1 Constant, 

Uncertainty

No No X No No X

Psample—the 

probability that 

a random 

sample will test 

positive for 

viral pathogens 

given a 

contaminated 

source water 

(adopted from 

GWR EA)

Variable drawn 

from a beta 

distribution with 

a range of 

alpha and beta 

estimates 

having a 

median value of 

5.8 percent and 

an expected 

value of 12.4 

percent.

5.3.1 Variability,

Uncertainty

No No X No No X
Economic Analysis for the Final RTCR 4-28 September 2012

Uncertainty 

Factor

Current 

Assumption

Section 

with Full 

Discussion

Contributes 

Variability, 

Uncertainty, 

or 

Constant?

Most Likely Effect on Benefits1 Most Likely Effect on Costs1

Underestimate Overestimate Unknown 

Impact Underestimate Overestimate Unknown Impact

Reduced 

occurrence for 

sanitary 

surveys 

performed 

under the 

GWR

90 percent of 

baseline 

occurrence; 

applied to equal 

number of 

systems 

annually over 

the sanitary 

survey cycle 

(20 percent 

each year of 5 

years for 

CWSs; 33.3 

percent each 

year for 3 years 

for NCWSs)

5.3.1 Constant, 

Uncertainty

No No X No No X

Reduced 

occurrence for 

GWR 

compliance 

monitoring 

(applies to 

subset of GW 

Systems that 

disinfect).

90 percent of 

baseline 

occurrence

5.3.1 Constant, 

Uncertainty

No No X No No X

Percentage of 

nondisinfecting

GW Systems 

choosing 

disinfection 

corrective 

action vs. nondisinfection 

Range: High 

end is the 

percentage of 

CWS entry 

points 

employing 

disinfection by 

system size, 

5.3.1 Constant, 

Uncertainty

No No X No No X
Economic Analysis for the Final RTCR 4-29 September 2012

Uncertainty 

Factor

Current 

Assumption

Section 

with Full 

Discussion

Contributes 

Variability, 

Uncertainty, 

or 

Constant?

Most Likely Effect on Benefits1 Most Likely Effect on Costs1

Underestimate Overestimate Unknown 

Impact Underestimate Overestimate Unknown Impact

corrective 

action in 

response to 

source water 

quality issue 

(adopted from 

GWR)

low end 

assumed to be 

10 percent 

based on 

discussions 

with State 

representatives.

Population and 

sensitive sub 

population 

estimates

Varies by 

category

4.2.3.3 and 

4.4

Variability, 

Uncertainty

No No X No No X

Notes:

1) All baseline variables or factors were incorporated into the predictive model in the same way for the 1989 TCR (baseline option) and the other two regulatory options 

considered in this EA (RTCR and Alternative Option), therefore EPA expects that any under- or overestimation would affect the baseline and other options similarly, 

resulting in no net effect on the results of the analysis.

2) A complete discussion of the data cleaning and assumption used in preparing Six-Year Review data for use in the RTCR baseline is provided in the Total Coliform 

Rule Compliance Monitoring Data Quality and Completion Report (USEPA, 2010e).
Economic Analysis for the Final RTCR 5-1 September 2012 

5 Occurrence and Predictive Model 

5.1 Introduction 

Based on evaluation of the Safe Drinking Water Information System/Federal Version 

(SDWIS/FED) violation data, the U.S. Environmental Protection Agency (EPA) assumes that the 

national occurrence of total coliform (TC) and E. coli (EC) has reached a steady state in recent 

years under the 1989 Total Coliform Rule (TCR). Cycles of normal deterioration and 

repair/replacement appear to be occurring at the individual system level, while the numbers of 

violations at the national level remain relatively unchanged. Chapter 4 (Exhibit 4.11) presents the 

number of public water systems (PWSs) with TCR violations from 2001–2007, which shows that 

national violation rates have remained relatively steady. Revisions to the 1989 TCR would affect 

this steady state, likely resulting in a reduction of the underlying occurrence and associated 

violations. However, prior to the Revised Total Coliform Rule (RTCR) implementation, the 

Ground Water Rule (GWR), which became effective December 2009, would also have an effect 

on the steady state. This chapter explains the development of a model that both reproduces the 

steady-state occurrence conditions under the 1989 TCR and predicts the effects of both the 

RTCR and the GWR in further reducing occurrence from current estimated levels. 

The occurrence and predictive model developed for the RTCR was used for PWSs 

serving 4,100 people or fewer, and it has two components. Occurrence and predictive modeling 

focuses on PWSs serving ≤4,100 people because (a) there are adequate data to support 

development of the occurrence distributions that are needed for the predictive components of the 

model, (b) these systems are known to have higher occurrence levels than systems serving 

>4,100 people, and (c) these systems, in particular, are subject to changes in the monitoring 

requirements under the RTCR. The first component of the model characterizes how the presence 

or positive rates of TC and EC detections vary across the population of PWSs serving ≤4,100 

people in the U.S. These rates vary by the type of sample (routine or repeat), by analyte (TC or 

EC), by system type (community water system (CWS), nontransient noncommunity water 

system (NTNCWS), or transient noncommunity water systems (TNCWS)), and by system size. 

EPA determined from the Six-Year Review data23 that systems differ considerably with respect 

to the observed occurrence of TC and EC in both routine and repeat sampling. Some of this 

variability can be explained by the type, size, water source, and disinfection practices of the 

systems. However, even among systems having the same characteristics, some systems were 

found to rarely experience positive assays, while others often did experience positive assays. The 

second component of the model uses the TC and EC occurrence distributions, together with the 

various sampling and response requirements, to simulate a set of nationally-representative 

systems within the context of the three regulatory options (1989 TCR, RTCR, and Alternative 

option) to predict changes in TC and EC occurrence, triggers, assessments, corrective actions 

over time, and violations. The model generates estimates of reduced TC and EC occurrence 

based on requirements of the RTCR to perform assessments and corrective actions not explicitly 

required in the 1989 TCR. Additionally, the occurrence model takes into account reductions 

attributable to the implementation of the GWR.

 

23 A discussion of the use of data from the Six-Year Review of SDWA regulations is presented in Chapter 4 of this 

EA. 
Economic Analysis for the Final RTCR 5-2 September 2012 

The occurrence model produces outputs over a 30-year time horizon24 that include 

national estimates of TC and EC occurrence in PWSs across the U.S., and the resulting Level 1 

and Level 2 assessments25 and corrective actions performed. These outputs are used to 

characterize reduced exposure to the potential contamination under each regulatory option 

considered, as presented in Chapter 6 of this economic analysis (EA), and to estimate the net 

change in costs (i.e., incremental costs over the 1989 TCR) for PWSs across the U.S., as 

described in Chapter 7 of this EA. 

The two major components of the occurrence and predictive model used for systems 

serving ≤4,100 people are described in Sections 5.2 and 5.3 of this chapter.

For systems serving more than 4,100 people, EPA estimated violation and trigger rates 

using SDWIS/FED (USEPA, 2005) because the Six-Year Review data for PWSs serving more 

than 4,100 people were not as robust as the Six-Year Review data for systems serving 4,100 or 

fewer people. EPA did not quantify changes in violation or trigger rates for systems serving more 

than 4,100 people among the 1989 TCR, RTCR, and Alternative option for the following 

reasons: (1) limited Six-Year Review data to characterize these systems, (2) essentially 

unchanged monitoring requirements across the regulatory options for these systems, and (3) level 

of effort already occurring to implement the 1989 TCR. A complete description of the methods 

for developing the occurrence estimates as described above is found in the remaining sections of 

this chapter: 

 Section 5.2 describes development of occurrence models to describe the occurrence 

of TC and EC for systems serving less than or equal to 4,100 people. 

 Section 5.3 describes how the occurrence model developed for systems serving less 

than or equal to 4,100 people (Sections 5.3.1–5.3.2) is used to predict occurrence 

following assessments and corrective actions (5.3.3) and includes a comprehensive 

list of assumptions contributing to uncertainty, a sensitivity analysis, and a 

discussion of model validation (5.3.3.1–5.3.3.2). 

 Section 5.4 describes how outcomes were predicted for systems serving more than 

4,100 people. 

 

24 The occurrence model includes an additional 5 years prior to the promulgation of the RTCR monitoring to 

account for effects of the GWR after it is fully implemented, plus 25 years of RTCR analysis, for a total of 30 

modeled years. 

25 The RTCR and Alternative option require PWSs to complete either a Level 1 or Level 2 assessment following 

triggers specified in Exhibit 3.1 of this EA. The purpose of Level 1 and 2 assessments is to identify the presence of 

sanitary defects and deficiencies in distribution system coliform monitoring practices, similar to an annual 

inspection but more focused on determining the cause of a contamination event. In order to complete a Level 2 

assessment the PWS must perform a more detailed examination of the system than for a Level 1 assessment, 

including its monitoring and operational practices. 
Economic Analysis for the Final RTCR 5-3 September 2012 

5.2 Modeling of Current Total Coliform and E. coli Occurrence for Systems Serving 

≤4,100 People 

This section describes the development of parameters used to define variability across 

and within groups of similar PWSs with regard to occurrence of TC and EC. Details related to 

this section are provided in Appendix F to this EA. 

5.2.1 Distributional Model and Notation 

The Six-Year Review data demonstrate that, even among systems of similar size and 

type, there are some PWSs that rarely find routine samples to be TC-positive and others that 

often find TC-positive samples. For example, among the TNCWSs serving ≤101 people that are 

using nondisinfected ground water, 47 systems reported ten or more routine TC positives while 

assaying 40 or fewer samples during 2005. Among the same set of TNCWSs with nondisinfected 

ground water are 60 that assayed 20 or more routine samples, finding all of them TC-negative. 

Clearly, routine TC-positive rates vary considerably within this set of systems. Different 

fractions of positives can be found among any basic subset of systems (defined by system type, 

water type, and population served, as described in Section 5.2.2 of this EA) and for any type of 

assay (both routine and repeat TC and both routine and repeat EC). 

Within a group of similar systems, pRTTCi

, which is defined as the probability that a 

routine sample taken from system i will test positive, is assumed to vary as a beta random 

variable. The beta distribution is commonly used to model varying probabilities because it is 

limited to values between 0 and 1 and can assume a wide variety of shapes. EPA used a beta 

distribution to describe how probabilities of virus-positive samples vary among viruscontaminated wells in the EA for the Ground Water Rule (USEPA, 2006a).

Samples that test negative for TC are generally not tested further for the presence of EC, 

unlike TC-positive samples. The probability that a TC-positive routine sample taken from system 

i will also test EC-positive (EC+), pRTECi, is assumed to vary among similar systems as another 

beta random variable, but with parameters that can be quite different from those of the routine 

TC samples. Although systems with frequent routine TC positives necessarily generated more 

EC assays, the EC+ rates for these systems did not appear to be significantly different than the 

EC+ rates of systems with rare TC positives. The variables pRTTC and pRTEC are therefore 

modeled as independent beta-distributions. 

Similar assumptions are extended to the repeat positive probabilities, pRPTCi and 

pRPECi. Like pRTTCi and pRTECi, these are assumed to be independently beta-distributed 

among sets of similar systems. A process for determining “sets of similar systems” is described 

in Sections 5.2.3 and 5.2.4. The process is informed by system-specific data that are reduced 

from the sample-specific data described in Chapter 4 of this EA, as discussed in the following 

section. 

5.2.2 Data Reduction 

The occurrence model assumes that positive routine TC measurements for system i result 

from some unobserved probability (pRTTCi). This probability may vary from month-to-month 

and season-to-season. However, in this model each result, whether positive or negative, is 
Economic Analysis for the Final RTCR 5-4 September 2012 

assumed to be an independent trial with positive probability pRTTCi. Each of these is called a 

Bernoulli trial. The total number of positives observed for system i during a year (KRTTCi) is 

therefore a binomial random variable, whose parameters are the system’s positive probability 

(pRTTCi) and the total number of samples assayed (NRTTCi). Data for the system can be 

reduced to the number of positive samples (KRTTCi) and the number of samples assayed 

(NRTTCi). The leading character “N” designates the number of samples tested and “K”

designates the number positive. 

Similarly, the routine EC data for system i can be reduced to the number of routine TCpositive samples that were assayed for EC (NRTECi) and, of those, the number testing positive 

(KRTECi). For many systems, both NRTEC and KRTEC will be zero because they encountered 

no routine TC positives during 2005 (KRTTC = 0), and EPA assumes that in the case of a TCnegative, no EC assay is performed. 

Finally, the data for repeat samples for system i can be reduced to four numbers: NRPTC, 

KRPTCi, NRPECi, and KRPECi. Again, the leading characters, “N” and “K”, designate numbers 

of samples assayed and numbers positive, respectively. “RP” designates that these are repeat 

samples, while “TC” and “EC” designate assays for TC and EC, respectively. For many systems, 

all four of these numbers are zero because no routine samples were TC positive. 

It is important to note that only TC-positive samples are assayed for EC. The positive 

probabilities for EC are therefore conditional, that is, they apply only to samples that have tested 

TC positive. All TC-negative samples are assumed to be EC negative. The overall 

(unconditional) probability that a routine sample from system i will be EC+ is the product 

pRTTCi*pRTECi and the overall (unconditional) probability that a repeat sample from the 

system will be EC+ is the product pRPTCi*pRPECi

. 

The reduced dataset includes eight integer values (for NRTTC, KRTTC, NRTEC, 

KRTEC, NRPTC, KRPTC, NRPEC, KRPEC) for each of approximately 93,000 systems. 

Although none of the NRTTC is zero (all systems assayed at least one routine TC sample during 

2005), the great majority of the other values are zeros. 

5.2.3 Basic Subsets of Systems 

The 92,747 systems serving ≤4,100 people in the Six-Year Review dataset (which 

represent the approximately 147,000 total systems that exist in this size range) can be classified 

by system type, source water type and disinfection status, and population served. The three types 

of systems are CWS, NTNCWS and TNCWS. The three source water types are surface water 

(SW), which is always disinfected, nondisinfected ground water (NondisGW) and disinfected 

ground water (DisGW). Three important size categories are systems serving ≤100 people, 

systems serving 101 to 1,000 people, and systems serving 1,001 to 4,100 people. Systems 

serving more than 4,100 people are not included here, for reasons discussed in Chapter 4 of this 

EA and earlier in this chapter. In total, there are 27 possible categories that each PWS may 

belong to (3 system types x 3 source water types x 3 population served sizes). Each PWS may 

only be in one of the 27 categories. Exhibit 5.1 lists the 27 basic subsets and corresponding 

numbers of systems in the dataset. 
Economic Analysis for the Final RTCR 5-5 September 2012 

Exhibit 5.1 Basic Classifications of PWSs Used for Occurrence Modeling 

System Type Water Type Population 

Served Group

Number of 

Systems in 6-

Year Review 

Data

CWS SW ≤100 484

CWS SW 101-1,000 2,034

CWS SW 1,001-4,100 1,699

CWS DisGW ≤100 3,662

CWS DisGW 101-1,000 7,678

CWS DisGW 1,001-4,100 2,707

CWS NondisGW ≤100 3,788

CWS NondisGW 101-1,000 3,755

CWS NondisGW 1,001-4,100 644

NTNCWS SW ≤100 114

NTNCWS SW 101-1,000 172

NTNCWS SW 1,001-4,100 33

NTNCWS DisGW ≤100 1,577

NTNCWS DisGW 101-1,000 1,780

NTNCWS DisGW 1,001-4,100 252

NTNCWS NondisGW ≤100 4,026

NTNCWS NondisGW 101-1,000 3,264

NTNCWS NondisGW 1,001-4,100 152

TNCWS SW ≤100 838

TNCWS SW 101-1,000 358

TNCWS SW 1,001-4,100 30

TNCWS DisGW ≤100 8,112

TNCWS DisGW 101-1,000 3,007

TNCWS DisGW 1,001-4,100 119

TNCWS NondisGW ≤100 32,028

TNCWS NondisGW 101-1,000 10,217

TNCWS NondisGW 1,001-4,100 217

TOTAL 92,747

Source: Derived using 2005 Six-Year Review 2 Data.

Note: Water Type includes disinfection status, as informed by information 

from SDWIS/FED. Systems with no indication of disinfection status in 

SDWIS/FED were assumed to not disinfect (Nondis).
Economic Analysis for the Final RTCR 5-6 September 2012 

5.2.4 Estimation Methodology 

The methodology described in this section applies to all four kinds of 

measurements, routine TC (RTTC), routine EC (RTEC), repeat TC (RPTC) and repeat EC

(RPEC). However, to simplify the presentation, the description will be expressed only in terms 

of RTTC. Results presented in Section 5.2.5 show that the final system classifications used to 

model TC (both routine and repeat) are quite different from the final subsets used to model EC 

occurrence. 

For any individual subset of systems from Exhibit 5.1 or grouping of these subsets, two 

methods were used to estimate parameters of the beta-distributed RTTC: maximum likelihood 

estimation and Bayesian Markov Chain Monte Carlo (MCMC) sampling. The MCMC samples 

are used to test whether two basic subsets have equal average positive rates and to check the 

maximum likelihood estimates (MLEs). This check was conducted to ensure that the algorithm 

used to find the MLE had not stopped running too soon. 

Both the MLE and MCMC methodologies require computation of the likelihood function, 

L(data | ), where  and  are parameters of beta-distributed pRTTC. For a specific system in 

a set of similar systems, the number of positive RTTC samples is a binomial random variable 

with parameters NRTTC and pRTTC, which are the numbers of RTTC samples assayed by the 

system and the system’s unobserved probability of a positive, respectively. The probability of a 

positive, pRTTC, is a beta random variable, whose parameters are  and  Exhibit 5.2 is a 

directed graph showing the model structure. At the top are the two high-level parameters ( and 

and arrows from them showing their influence on the distribution of the system-specific 

parameters, the positive probabilities or pRTTCs. Finally, the exhibit shows how the pRTTCs, 

together with the numbers of samples assayed (NRTTCs), influenced the numbers estimated to 

be positive (KRTTCs). 
Economic Analysis for the Final RTCR 5-7 September 2012 

Exhibit 5.2 Directed Graph of Model Used for RTTC Occurrence 

This same model could have been equally well represented with all of the arrows pointing 

up to show the direction of inference, starting with the data (NRTTCs and KRTTCs), which 

inform estimates of the unobserved positive probabilities (pRTTCs), and then those informing 

estimates of the high level parameters ( and 

5.2.4.1 Maximum Likelihood Estimation 

From this point through the end of this chapter, the approach for estimating parameters 

for routine TC occurrence (RTTC) is the same approach used for repeat TC (RPTC) and both 

routine and repeat EC occurrence (RTEC and RPEC). To simplify the notation, the designation 

of measurement type (e.g., RTTC) will be dropped. For example, KRTTC is reduced to K, 

NRTTC is reduced to N, and pRTTC is reduced to p. Subscript i is used to denote a particular 

system in a basic subset of systems. 

For a single system in a subset, if pi were known, the likelihood of the system’s RTTC 

data (Ki positives observed among Ni routine samples) would be given by the binomial 

probability mass function: 

 N ! 

dbinom (K , N ,p ) ip

Ki Ni K

i i i   i

(1 pi)

 i

 

K !i i (N  Ki

)!
Economic Analysis for the Final RTCR 5-8 September 2012 

But pi is not known, nor can it be observed explicitly. It is, therefore, treated as a beta 

random variable. The expected value of the likelihood function is obtained by integrating the 

product of the beta probability density function and the binomial probability mass function. The 

beta probability density function is: 

(  )



()()





p 

1

1  p

i  i

1



And the expected likelihood is: 

1

 N !  i Γ(α  β) α1Ki β1NiKi

  (p) (1  p) dp

K ! N Γ( )Γ )

i 

 K i ! α (β  i



0

 Because both Ni and Ki are constant (observed data), the function only depends on the 

factors involving p, , and , so the factorial terms in the above may be ignored when seeking to 

maximize the likelihood function. This simplifies the computation considerably, and the 

resulting integral has a closed-form solution, which is: 

Γ(α  β)Γα  K Γβ  N  K  Beta α  K  β  N  K i i i  i i i

=

Γ(α)Γ(β)Γα  β  Ni Beta(α β)

The total likelihood for a set of systems is the product of the system-specific likelihoods: 

Beta  K    N  K i i i

Likelihood( )  Beta(  )

i

In order to find maximum likelihood estimates of parameters  and , some additional 

steps were taken: 

1. Log likelihood, rather than likelihood, was computed to avoid the problems of 

numerical overflow and underflow. Because the log transformation is positive and 

monotonic, parameters found to maximize the log likelihood function will also 

maximize the untransformed likelihood function: 

 Beta  K    N  K i i i 

LogLikelihood( ) ln 

 Beta(  ) 

i

2. Parameters of the Beta distribution were expressed in terms of the mean (a=) 

and dispersion (b=1/sqrt()). In terms of these new parameters, the log likelihood 

function is: 
Economic Analysis for the Final RTCR 5-9 September 2012 

  a 1  a   Beta  K    N  K   i i i 2 2 

  b b   LogLikelihood (a b) ln  a 1  a  

i Beta 

    2 2   b b  

3. Bayesian MCMC estimation, as described in Appendix F was used to check the 

MLEs and to support decisions about combining (pooling) different categories or 

subsets of systems. 

4. Where subsets of systems were found to have insufficient data to support maximum 

likelihood estimation, engineering judgment was used to decide if combining with 

other subsets made sense, for the purpose of parameter estimation. Rationale and 

strategies for this are described in Appendix F. 

5.2.5 Results 

Appendix F of this EA describes how systems and their data were combined, or pooled, 

for the purpose of RTTC, RTEC, RPTC, and RPEC modeling. Section 5.2.5.1 and 5.2.5.2 report 

the resulting MLEs in terms of a, b and α, β. 

RTTC data were addressed first because: a) so much more data were available for RTTC 

than for the other three measurement types (RTEC, RPTC, and RPEC); and b) summary statistics 

suggested that systematic differences due to system size and other factors were larger for TC 

than for EC measurements. 

When evaluating data for any one type of measurement, system size was evaluated first 

because it was expected to be important for a number of reasons, primarily: a) larger systems 

have more resources and are more likely to employ full-time professional operators than smaller 

systems; and b) having more resources, the larger systems may provide better treatment and 

distribution systems. System type and water type were evaluated after system size, but the order 

in which these were evaluated does not appear to have been important. 

5.2.5.1 Maximum Likelihood Estimates (MLEs) 

Exhibit 5.3 provides MLEs for routine and repeat TC, while Exhibit 5.4 provides MLEs 

for routine and repeat EC. Note that both of these exhibits present the a and b parameters as 

defined in Section 5.2.4.1.
Economic Analysis for the Final RTCR 5-10 September 2012 

Exhibit 5.3 Maximum Likelihood a and b Parameter Estimates for RTTC and RPTC 

Size No. Systems aRTTC bRTTC aRPTC bRPTC

≤100 484 0.01502 0.2090 0.06464 0.6107

101-1,000 2,034 0.009458 0.1490 0.06464 0.6107

1,001-4,100 1,699 0.005864 0.1275 0.03430 0.2721

≤100 3,662 0.01592 0.2243 0.09415 0.8493

101-1,000 7,678 0.01243 0.2142 0.09415 0.8493

1,001-4,100 2,707 0.007767 0.1841 0.05221 0.4916

≤100 3,788 0.03147 0.2680 0.1898 0.8407

101-1,000 3,755 0.02690 0.2840 0.1898 0.8407

1,001-4,100 644 0.02690 0.2840 0.1312 0.6938

≤100 114 0.01584 0.3576 0.1064 1.078

101-1,000 172 0.01127 0.2458 0.1064 1.078

1,001-4,100 33 0.01127 0.2458 0.1064 1.078

≤100 1,577 0.01584 0.3576 0.1064 1.078

101-1,000 1,780 0.01127 0.2458 0.1064 1.078

1,001-4,100 252 0.01127 0.2458 0.1064 1.078

≤100 4,026 0.03658 0.4044 0.2575 0.9319

101-1,000 3,264 0.02690 0.2840 0.2575 0.9319

1,001-4,100 152 0.02690 0.2840 0.2575 0.9319

≤100 838 0.02312 0.2992 0.1439 1.108

101-1,000 358 0.02312 0.2992 0.1439 1.108

1,001-4,100 30 0.02312 0.2992 0.1439 1.108

≤100 8,112 0.02312 0.2992 0.1439 1.108

101-1,000 3,007 0.02312 0.2992 0.1439 1.108

1,001-4,100 119 0.02312 0.2992 0.1439 1.108

≤100 32,028 0.04758 0.3990 0.2788 1.068

101-1,000 10,217 0.04758 0.3990 0.2487 0.9359

1,001-4,100 217 0.02467 0.3121 0.1694 0.4052

Nontransient, Noncommunity Water Systems (NTNCWSs), Ground Water (GW), Disinfecting

Note: Disinfection status (“Disinf?”) is from information downloaded from SDWIS/FED. Systems with no indication of 

disinfection status in SDWIS/FED are assumed to not disinfect.

Transient, Noncommunity Water Systems (TNCWSs), Ground Water (GW), Non-Disinfecting

Community Water Systems (CWSs), Surface Water (SW), Disinfecting

Community Water Systems (CWSs), Ground Water (GW), Disinfecting

Community Water Systems (CWSs), Ground Water (GW), Non-Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Surface Water (SW), Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Ground Water (GW), Non-Disinfecting

Transient, Noncommunity Water Systems (TNCWSs), Surface Water (SW), Disinfecting

Transient, Noncommunity Water Systems (TNCWSs), Ground Water (GW), Disinfecting
Economic Analysis for the Final RTCR 5-11 September 2012 

Exhibit 5.4 Maximum Likelihood a and b Parameter Estimates for RTEC and RPEC 

Size No. Systems aRTEC bRTEC aRPEC bRPEC

≤100 484 0.1291 0.6287 0.05175 1.153

101-1,000 2,034 0.1291 0.6287 0.05175 1.153

1,001-4,100 1,699 0.07514 0.8767 0.05175 1.153

≤100 3,662 0.05449 0.6387 0.03950 1.168

101-1,000 7,678 0.05449 0.6387 0.03950 1.168

1,001-4,100 2,707 0.05449 0.6387 0.03950 1.168

≤100 3,788 0.04223 0.8129 0.03569 1.059

101-1,000 3,755 0.04223 0.8129 0.03569 1.059

1,001-4,100 644 0.04223 0.8129 0.03569 1.059

≤100 114 0.1291 0.6287 0.05175 1.153

101-1,000 172 0.1291 0.6287 0.05175 1.153

1,001-4,100 33 0.1291 0.6287 0.05175 1.153

≤100 1,577 0.08599 0.8796 0.07063 1.196

101-1,000 1,780 0.08599 0.8796 0.07063 1.196

1,001-4,100 252 0.08599 0.8796 0.07063 1.196

≤100 4,026 0.04223 0.8129 0.03569 1.059

101-1,000 3,264 0.04223 0.8129 0.03569 1.059

1,001-4,100 152 0.04223 0.8129 0.03569 1.059

≤100 838 0.1291 0.6287 0.05175 1.153

101-1,000 358 0.1291 0.6287 0.05175 1.153

1,001-4,100 30 0.1291 0.6287 0.05175 1.153

≤100 8,112 0.08599 0.8796 0.07063 1.196

101-1,000 3,007 0.08599 0.8796 0.07063 1.196

1,001-4,100 119 0.08599 0.8796 0.07063 1.196

≤100 32,028 0.04223 0.8129 0.03569 1.059

101-1,000 10,217 0.04223 0.8129 0.03569 1.059

1,001-4,100 217 0.04223 0.8129 0.03569 1.059

Nontransient, Noncommunity Water Systems (NTNCWSs), Surface Water (SW), Disinfecting

Transient, Noncommunity Water Systems (TNCWSs), Surface Water (SW), Disinfecting

Transient, Noncommunity Water Systems (TNCWSs), Ground Water (GW), Non-Disinfecting

Note: Disinfection status (“Disinf?”) is from information downloaded from SDWIS/FED. Systems with no indication of 

disinfection status in SDWIS/FED are assumed to not disinfect.

Transient, Noncommunity Water Systems (TNCWSs), Ground Water (GW), Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Ground Water (GW), Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Ground Water (GW), Non-Disinfecting

Community Water Systems (CWSs), Surface Water (SW), Disinfecting

Community Water Systems (CWSs), Ground Water (GW), Disinfecting

Community Water Systems (CWSs), Ground Water (GW), Non-Disinfecting
Economic Analysis for the Final RTCR 5-12 September 2012 

5.2.5.2 Derivation of α, β from Maximum Likelihood Estimates 

Using the estimates of a and b presented in Exhibits 5.3 and 5.4, EPA derived α, β

estimates of the variation in PWSs within groups of systems, and incorporated these into the 

occurrence model as described in Section 5.2.4.1. 

These parameters are derived from a and b as follows: 

2  = a / b

2  = (1- a) / b

Exhibits 5.5 and 5.6 present the estimates of α, β corresponding to estimates of a and b in 

exhibits 5.3 and 5.4. 
Economic Analysis for the Final RTCR 5-13 September 2012 

Exhibit 5.5 α and β Parameter Estimates for RTTC and RPTC 

Size No. Systems αRTTC βRTTC αRPTC βRPTC

≤100 484 0.3438 22.54 0.173 2.508

101-1,000 2,034 0.4262 44.63 0.173 2.508

1,001-4,100 1,699 0.3608 61.17 0.463 13.04

≤100 3,662 0.3166 19.57 0.1305 1.256

101-1,000 7,678 0.2709 21.53 0.1305 1.256

1,001-4,100 2,707 0.2291 29.26 0.2160 3.922

≤100 3,788 0.4381 13.49 0.2685 1.146

101-1,000 3,755 0.3336 12.07 0.2685 1.146

1,001-4,100 644 0.3336 12.07 0.2726 1.805

≤100 114 0.1239 7.697 0.092 0.7697

101-1,000 172 0.1866 16.37 0.092 0.7697

1,001-4,100 33 0.1866 16.37 0.092 0.7697

≤100 1,577 0.1239 7.697 0.09164 0.7697

101-1,000 1,780 0.1866 16.37 0.09164 0.7697

1,001-4,100 252 0.1866 16.37 0.09164 0.7697

≤100 4,026 0.2236 5.890 0.2965 0.8550

101-1,000 3,264 0.3336 12.07 0.2965 0.8550

1,001-4,100 152 0.3336 12.07 0.2965 0.8550

≤100 838 0.2584 10.92 0.117 0.6972

101-1,000 358 0.2584 10.92 0.117 0.6972

1,001-4,100 30 0.2584 10.92 0.117 0.6972

≤100 8,112 0.2584 10.92 0.1172 0.6972

101-1,000 3,007 0.2584 10.92 0.1172 0.6972

1,001-4,100 119 0.2584 10.92 0.1172 0.6972

≤100 32,028 0.2989 5.983 0.2444 0.6323

101-1,000 10,217 0.2989 5.983 0.2839 0.8577

1,001-4,100 217 0.2532 10.01 1.03175 5.059

Note: Disinfection status (“Disinf?”) is from information downloaded from SDWIS/FED. Systems with no indication of 

disinfection status in SDWIS/FED are assumed to not disinfect.

Transient, Noncommunity Water Systems (TNCWSs), Ground Water (GW), Non-Disinfecting

Transient, Noncommunity Water Systems (TNCWSs), Ground Water (GW), Disinfecting

Community Water Systems (CWSs), Ground Water (GW), Non-Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Surface Water (SW), Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Ground Water (GW), Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Ground Water (GW), Non-Disinfecting

Transient, Noncommunity Water Systems (TNCWSs), Surface Water (SW), Disinfecting

Community Water Systems (CWSs), Surface Water (SW), Disinfecting

Community Water Systems (CWSs), Ground Water (GW), Disinfecting
Economic Analysis for the Final RTCR 5-14 September 2012 

Exhibit 5.6 α and β Parameter Estimates for RTEC and RPEC

Size No. Systems αRTEC βRTEC αRPEC βRPEC

≤100 484 0.3266 2.203 0.03891 0.7129

101-1,000 2,034 0.3266 2.203 0.03891 0.7129

1,001-4,100 1,699 0.0978 1.203 0.03891 0.7129

≤100 3,662 0.1336 2.318 0.02896 0.7041

101-1,000 7,678 0.1336 2.318 0.02896 0.7041

1,001-4,100 2,707 0.1336 2.318 0.02896 0.7041

≤100 3,788 0.0639 1.449 0.03184 0.8602

101-1,000 3,755 0.0639 1.449 0.03184 0.8602

1,001-4,100 644 0.0639 1.449 0.03184 0.8602

≤100 114 0.3266 2.203 0.03891 0.7129

101-1,000 172 0.3266 2.203 0.03891 0.7129

1,001-4,100 33 0.3266 2.203 0.03891 0.7129

≤100 1,577 0.1112 1.181 0.04936 0.6496

101-1,000 1,780 0.1112 1.181 0.04936 0.6496

1,001-4,100 252 0.1112 1.181 0.04936 0.6496

≤100 4,026 0.0639 1.449 0.03184 0.8602

101-1,000 3,264 0.0639 1.449 0.03184 0.8602

1,001-4,100 152 0.0639 1.449 0.03184 0.8602

≤100 838 0.3266 2.203 0.03891 0.7129

101-1,000 358 0.3266 2.203 0.03891 0.7129

1,001-4,100 30 0.3266 2.203 0.03891 0.7129

≤100 8,112 0.1112 1.181 0.04936 0.6496

101-1,000 3,007 0.1112 1.181 0.04936 0.6496

1,001-4,100 119 0.1112 1.181 0.04936 0.6496

≤100 32,028 0.0639 1.449 0.03184 0.8602

101-1,000 10,217 0.0639 1.449 0.03184 0.8602

1,001-4,100 217 0.0639 1.449 0.03184 0.8602

Note: Disinfection status (“Disinf?”) is from information downloaded from SDWIS/FED. Systems with no indication of 

disinfection status in SDWIS/FED are assumed to not disinfect.

Transient, Noncommunity Water Systems (TNCWSs), Ground Water (GW), Disinfecting

Transient, Noncommunity Water Systems (TNCWSs), Ground Water (GW), Non-Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Ground Water (GW), Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Ground Water (GW), Non-Disinfecting

Transient, Noncommunity Water Systems (TNCWSs), Surface Water (SW), Disinfecting

Community Water Systems (CWSs), Surface Water (SW), Disinfecting

Community Water Systems (CWSs), Ground Water (GW), Disinfecting

Community Water Systems (CWSs), Ground Water (GW), Non-Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Surface Water (SW), Disinfecting
Economic Analysis for the Final RTCR 5-15 September 2012 

5.3 Predictive Modeling of Occurrence for Systems Serving Up to 4,100 People 

For the purpose of understanding both the potential to reduce exposure to potential 

contamination and for estimating the net change in costs that may be incurred under the RTCR, 

EPA developed a model to predict the changes in TC and EC occurrence over the modeled 

period with respect to requirements of the RTCR regulatory options. This predictive occurrence 

model takes into account the requirements of existing regulations (1989 TCR and GWR) and 

develops estimates of changes in occurrence (as well as the frequency of the new Level 1 and 

Level 2 assessments and corrective actions) based on requirements of the regulatory options 

considered under the RTCR. The resulting estimates are used to generate cost estimates that can 

be compared across the three regulatory options26—the 1989 TCR, the RTCR, and the 

Alternative option, as described in Chapter 7 of this EA. Potential benefits are compared in terms 

of changes in the level of occurrence associated with each regulatory option, as presented in 

Chapter 6 of this EA. 

The occurrence model focuses on a 30-year period beginning with full implementation of 

the GWR and covering a 25-year period of analysis from the anticipated RTCR effective date of 

2015. The predictive model is implemented as a Monte Carlo simulation and currently uses 

10,000 iterations (simulated systems) within each of the 27 type, source and size categories to 

predict the effects of changes to the current rule over the modeling period. 

The PWSs included in this model are those serving ≤4,100 people primarily because 

these are the systems that will experience the major changes in monitoring frequency and other 

requirements that will affect their TC and EC occurrence. For systems serving more than 4,100 

people, which will not have significant monitoring frequency changes, a separate analysis was 

performed based on historical violations rates instead of occurrence rates, as explained in Section 

5.4 of this EA. The characteristics of all systems are described in Section 4.3 of this EA. 

5.3.1 Summary of GWR factors and timing affecting the 1989 TCR and RTCR 

The triggered and compliance monitoring requirements of the GWR must be 

implemented beginning December 2009, which will be approximately five years prior to the 

anticipated compliance date of the RTCR. Sanitary survey requirements must be implemented by 

states by December 2012 for most CWSs and not until December 2014 for higher performing 

CWSs and noncommunity water systems (NCWSs). To account for the impact of the GWR 

requirements on baseline occurrence for those PWSs using a ground water source (and serving 

≤4,100 people), the model performs a number of adjustments to the existing data prior to its 

application in the model as a baseline. 

 

26 The three regulatory options considered in the RTCR EA (1989 TCR, RTCR, and Alternative option) are 

described in detail in Chapter 3 of this EA. Briefly, the RTCR and Alternative option both differ from the 1989 TCR 

primarily in the requirements for Level 1 and Level 2 assessments and corrective actions and for reduced monitoring 

eligibility. The RTCR allows a continuation of current monitoring frequency while the Alternative option requires 

systems to sample monthly for an initial period. Both allow reduced monitoring for qualified systems, but only the 

RTCR allows annual monitoring. Systems on annual monitoring would require an annual site visit or an annual 

voluntary Level 2 assessment. 
Economic Analysis for the Final RTCR 5-16 September 2012 

Using 2005 SDWIS data (as explained in Section 4.3.1 of this EA) as a pre-GWR 

inventory baseline, EPA applies probabilities of Psample and Pwell

27 to determine the number of 

nondisinfecting systems that are expected to move to a disinfecting status in the five years prior 

to RTCR implementation. EPA derived Psample and Pwell

28 in the GWR EA (USEPA, 2006a); Pwell

is a fixed value of 21.58 percent, and Psample is drawn from a beta distribution with a range of 

alpha and beta estimates having a median value for each system of 5.8 percent and an expected 

value of 12.4 percent. Incorporation of these factors into the model ensures that the corrective 

actions anticipated to be performed under the GWR are reflected in reduced occurrence for 

systems implementing them. In the predictive model, simulated nondisinfecting ground water 

systems having a TC-positive (TC+) take one or more source water samples per the GWR 

triggered monitoring requirement and test the samples for fecal indicator presence (EC is 

assumed to be the fecal indicator used).29 The probability of observing an EC-positive (EC+) is 

based on the product of Pwell and the Psample value drawn for that system. If positive, a second 

assessment is done to determine if that system implements disinfection or a nondisinfection 

corrective action based on the estimated proportion choosing those options as defined in the 

GWR EA for the various types and sizes of systems.30

The simulation model keeps track of systems that begin as nondisinfecting ground water 

systems at the start of the analysis period and elect disinfection at some point during the 30-year 

period from the effective date of the GWR (December 2009) through the end of the analysis 

period for the RTCR. The inventory for disinfecting and nondisinfecting ground water systems 

are then adjusted accordingly for subsequent stages of the analysis. 

Exhibit 4.5 in Chapter 4 of this EA presents the baseline inventory of ground water 

systems (GW systems) by disinfection status at the beginning of RTCR implementation. Those 

GW systems achieving <4 log disinfection must sample at their source when they have a TC+ 

sample in their distribution system monitoring under the 1989 TCR and the RTCR. Sampling 

costs were accounted for in the GWR EA (USEPA, 2006a). 

Throughout the modeling period, GW systems that do not currently disinfect or add 

disinfection may have EC+ source water samples and implement a nondisinfection corrective 

action. Modeling in the GWR EA did not incorporate estimates of the effectiveness of 

implementing GWR requirements because the GWR was only effective as of December 2009. 

Absent this data, EPA applied best professional judgment in assuming that these corrective 

 

27 The term “Pwell” refers to the probability that a randomly selected well across the United States will test positive 

for a virus or fecal indicator species, such as EC, in its source water; “Psample” is the probability that given a 

contaminated well, a random sample at the well will eventually test positive for a virus or fecal indicator. The GWR 

EA (USEPA, 2006a), and in particular the Baseline Chapter of that document, provide a detailed explanation of the 

analysis used to generate these Pwell and Psample estimates. 

28 Under the GWR, GW systems with less than 4 log of treatment for viruses must sample their source for a fecal 

indicator (e.g., E. coli) when they incur a TC+ under the 1989 TCR (or RTCR). If sample water is fecal indicator 

positive, the system may be required to implement remedial actions at the source, one of which achieves disinfection 

to 4 log for viruses. 

29 Edberg, R. (2000) discusses the use of E. coli as an indicator of drinking water quality. 

30 Costs for compliance with the GWR were considered in the GWR EA (USEPA, 2006a) and are not included in 

the RTCR EA. 
Economic Analysis for the Final RTCR 5-17 September 2012 

actions would have approximately the same effectiveness as a Level 2 corrective action since 

they are similar in nature to an acute violation under the 1989 TCR. As shown in Exhibit 5.8, if a 

nondisinfecting system performs a nondisinfecting corrective action, the model assumes that 

occurrence is 0 percent for the remainder of that year and 2 full years after that. As a result of 

this assumption, baseline occurrence will be significantly reduced as a function of movement 

from nondisinfecting to disinfecting status. The modeling then assumes the P values are only 25 

percent of baseline values for an additional five years. The model assumes the system returns to 

baseline P values after that (approximately) seven year period. 

Additionally, the model incorporates the effect of SSs performed under the GWR as of 

January 2010, which is estimated by EPA to reduce TC and EC occurrence by 10 percent for the 

remainder of the period of analysis. For TNCWSs, which are on a 5-year SS cycle under the 

GWR, this reduction is initially applied to 20 percent of qualifying systems for each of the 5 

years from 2010 to 2015. For CWSs, which are on a 3-year cycle, this reduction is initially 

applied to 1/3 of systems annually from 2010 to 2012. EPA considers the estimate of 10 percent 

in reduction of occurrence to be a conservative estimate of the effectiveness of the SS provision 

of the GWR based on best professional judgment of the TCRDSAC. However, absent empirical 

information to assume otherwise and because the factor is similarly incorporated by the model 

into the estimates of occurrence for all three regulatory options, EPA assumes that this 

conservatism does not significantly affect the net results for the RTCR or Alternative option, 

which are calculated by comparison to the 1989 TCR (baseline). 

A third GWR requirement that the model incorporates is compliance monitoring by the 

subset of GW systems that disinfect, for which the model assigns a 10 percent reduction in 

occurrence in effect throughout the period of analysis. Again, this GWR effectiveness estimate 

may be conservative, but EPA assumes that because it is incorporated by the model into 

occurrence estimates for all three regulatory options, the net effect on results of the RTCR and 

Alternative option (in comparison to the 1989 TCR) is unlikely to be significant. Taking into 

account the effect of both SS and compliance reductions, the disinfecting GW systems are 

expected to ultimately have TC and EC occurrence rates that are 81 percent of the values derived 

from the occurrence distributions (from 90 percent for sanitary surveys x 90 percent for 

compliance monitoring). 

A fourth and last GWR requirement that the model incorporates concerns the repeat 

number of samples following a TC positive. For GW systems serving ≤1,000 people, the GWR 

allows the PWS to use of one of the four repeat samples required under the 1989 TCR following 

a TC+ sample to meet the requirement for source water testing under the GWR. By comparison, 

under the RTCR, Alternative option, and the 1989 TCR scenarios for systems serving >1,000

people, only 3 repeat samples are required following a TC+ and in these cases an additional, 

separate sample is used for the GWR source water fecal indicator assay. 

As mentioned above with regard to SS and disinfecting system GWR compliance, the 

actual reductions in occurrence that will result from implementation of GWR requirements may 

differ from those predicted based on assumptions used in this model. EPA believes this would 

affect neither the net analysis nor how the RTCR or Alternative option compare to each other, 

since both would be affected similarly. Section 5.3.3.1 describes the various sources of 

uncertainty and variability considered in this EA and presents an analysis of key variables. 
Economic Analysis for the Final RTCR 5-18 September 2012 

5.3.2 Summary of Predictive Model 

As the following Sections 5.3.2.1–5.3.2.2 describe, EPA modeled the expected trend in 

occurrence of TC and EC+ assays over a pre-RTCR monitoring period of 5 years (to capture 

applicable GWR effects), and a subsequent 25-year period of analysis for the three regulatory 

options: continuation of the 1989 TCR, RTCR, and Alternative option.31 EPA sought to capture 

the changes in occurrence from the implementation of the GWR requirements, and in turn, the 

implementation of requirements of the RTCR and the Alternative option. Along with changes in 

TC and EC occurrence, the model predicts behavioral changes: the number of Level 1 and Level 

2 assessments (and associated number of Level 1 or Level 2 corrective actions) to be performed 

and further resulting adjustments to occurrence, and changes in sampling regimens as systems 

qualify for reduced monitoring requirements. 

5.3.2.1 Approach to Estimating Parameters 

As described in Section 5.2 of this chapter, EPA derived Beta distributions, characterized 

by their α, β parameters, based on analyses of the variation in TC and EC+ assays that occurred 

both between and within 27 groupings of systems (as defined in Section 5.2.3); the resulting α, β

parameter estimates are presented in Exhibits 5.5 and 5.6. Based on an initial analysis, the 27 

groups were condensed into the groups presented in Appendix F of this EA. The final Beta 

distributions were based on these groupings to make the best use of the available data, combining 

groups of systems when their occurrence levels were similar to avoid having small sample size in 

any of the final groups. 

5.3.2.2 Description of Predictive Model 

Model output in this chapter (Exhibits 5.10–5.21) was generated for a 30-year period to 

encompass 5 years of the effects of GWR implementation and 25 years of the effects of RTCR 

implementation. For the purpose of the benefit-cost analysis, years 3 through 27 of this period 

are included in the calculations and presented in the results shown in Chapter 6 (Benefits 

Analysis), Chapter 7 (Cost Analysis), and Chapter 9 (Comparison of Benefits and Costs). 

Initially in the modeled period, all systems under the 1989 TCR and the RTCR are assumed to 

sample based on the sampling regimen applicable to their system type, size, type of water source, 

and whether or not the system disinfects on the effective date of the RTCR.32 Under the 

Alternative option, all systems are assumed to sample monthly for the first five years after the 

RTCR effective date. 

For the RTCR, the model adjusts these monitoring frequencies for GW systems serving 

fewer than 1,000 people in years 9 and 11 of the 30-year period, or following 3 and 5 years after 

of implementation of the RTCR, respectively, for CWSs and NCWSs. The adjustments are made 

based on the acute and non-acute violations modeled during these 3- and 5-year periods,33 and 

 

31 Footnote 4 briefly describes the three regulatory options, which are described in detail in Chapter 3 of this EA. 

32 Based on EPA and TWG analysis of Six-Year data and individual state statutes during the TCRDSAC and review 

by ASDWA. 

33 Systems modeled to incur one or more acute or non-acute violations in this period are assumed to be on monthly 

monitoring. For the RTCR, the remaining systems (incurring no acute or non-acute violations) are distributed 
Economic Analysis for the Final RTCR 5-19 September 2012 

the period of assessment coincides with the sanitary survey for CWSs and NCWSs. The adjusted 

monitoring frequencies then apply from years 9–30 and years 11–30 of the analysis for CWSs 

and NCWSs, respectively. 

For the Alternative option, the model adjusts the monitoring frequencies from the allmonthly regimen based on the acute and non-acute violations34 predicted during the assessment 

period, which is the first five years after the RTCR effective date, during which all systems 

sample monthly. The model applies the schedule thus adjusted in years 11–30 of the analysis. 

The timing for the adjustments made to the monitoring frequency schedules is consistent 

with the length of time of the respective sanitary survey cycles. Although EPA uses the sanitary 

cycle to define the period of assessment for updating the schedule, the results of the surveys are 

not predicted in this model and are not directly incorporated into the calculations in any way. 

Assumptions for the percentage of systems on monthly, quarterly, or annual monitoring upon 

RTCR implementation are shown in Exhibit 5.9a–5.9c. 

Using the monitoring frequencies described above, the model applies the baseline 

occurrence associated with each category of PWS at the start of each modeled year (i.e., the level 

of occurrence in 2005 under the 1989 TCR updated to reflect GWR implementation, as described 

in Section 5.3.1), as described in Exhibits 5.7 and 5.8 for SW and GW systems, respectively. The 

TC and EC occurrence (both from routine and repeat samples) are modeled by combining the 

Beta distributions described previously with the binomial distribution to simulate TC+ and EC+ 

results (i.e., successes) given the number of samples (i.e., trials) each month. 

For each simulated system in the model, a probability (P) is drawn randomly for each of 

the RTTC, RPTC, RTEC, and RPEC types of samples from their corresponding Beta 

distributions. These P values are used in the binomial distribution, together with the number of 

samples taken each month, to predict the number of TC+ and EC+ results. In the absence of any 

corrective actions being performed under the RTCR, those P values remain the same for that 

system for the entire modeling period. If TC or EC occurrence is found that results in a specific 

corrective action under the RTCR, temporary reductions in these P values are made as described 

further below. In addition, when a system has a TC+ in a particular month that does not result in 

a specific corrective action, it is assumed (for both the 1989 TCR and the RTCR) that the RTTC 

rate in the following month will change to reflect either some worsening of the problem or an 

improvement based on some other actions taken that are not part of the specific corrective 

actions being considered. This was carried out by selecting at random a different RTTC P value 

 

between quarterly and annual monitoring according to the percentage distribution from the initial M/Q/A estimates 

prior to GWR implementation (Exhibit 4.4). Constraints to these adjustments include: 1) the final estimates of the 

proportion of disinfecting CWSs on monthly monitoring should not decrease from the current baseline estimate; and 

2) for the disinfecting NCWSs, there are caps on the percent that move to annual monitoring under the RTCR 

(TNCWS <500: 13.8 percent, TNCWS 501-1,000: 8.6 percent, NTNCWS <500: 7.3 percent, NTNCWS 501-1,000: 

3.0 percent). 

34 Systems incurring one or more acute or non-acute violations in this period are assumed to be on monthly 

monitoring. For the Alternative option, all of the remaining systems (incurring no acute or non-acute violations) 

move to quarterly monitoring. 
Economic Analysis for the Final RTCR 5-20 September 2012 

in those months following a TC+ for which explicit corrective actions were not initiated. In the 

second month following a TC+ that does not result in a corrective action, the RTTC rate reverts 

to the rate applicable in the month in which the TC+ occurred. EPA determined that this 

approach provided overall results for the 1989 TCR that approximated what was observed in the 

6-Year Review data and SDWIS data as discussed in the Section 5.3.3.2 (model validation) 

below. 

Based on the frequency of sampling and the occurrence probabilities for each system, the 

model determines what percentage of these systems will be required to take an action (i.e., 

perform a Level 1 or Level 2 assessment in response to exceeding the threshold of multiple TC

positive assays or one EC+ assay, and, in some cases, implement a corrective action). 

For the percentage of systems predicted to require a Level 1 assessment following the 

requisite number of TC positives, the model assumes that 10 percent will find and address the 

exact source of the problem under the RTCR and Alternative option. This represents a net 

increase over the number expected to implement such a corrective action under the 1989 TCR. 

The model assumes that systems that successfully identify and correct the problem will not have 

a positive assay for the remainder of that year and also 1 additional full year after the assessment, 

after which the probability of a TC+ or EC+ will be 50 percent that of the baseline P value for 3 

additional years.35 After this period of reduced occurrence, the model assumes that occurrence 

probabilities for this subset of systems return to those that were initially assigned. Because the 

Level 1 and Level 2 assessments are a new requirement, empirical data on their effectiveness in 

determining an appropriate corrective action is not available. Absent this evidence, EPA has 

applied best professional judgment in choosing what it believes to be a significant but 

conservative success rate—10 percent of Level 1 assessments will result in determining the root 

of the problem and effectively implementing an appropriate corrective action. The assumptions 

about the success rates of assessments and corrective actions, and the length of time before and 

likelihood of subsequent positive samples, are assumptions made for modeling purposes and do 

not reflect the expectation for any particular system. 

Similarly, based on observing the requisite number of TC+ and/or EC+ results for 

systems predicted to require a Level 2 assessment under the RTCR and Alternative option, a 10 

percent increase in the number of systems from the 1989 TCR are assumed to implement a 

corrective action that addresses the cause of the problem. For those systems, the model assumes 

that occurrence is 0 percent for the remainder of that year and then for 2 full years after that. The 

modeling then assumes the P values are only 25 percent of baseline values for an additional 5 

years. The model assumes the system returns to baseline P values after that (approximately) 7-

year period. 

For nondisinfecting GW systems, a percentage of positive samples is estimated (from the 

Pwell and Psample parameters) to be related to a source water problem. All nondisinfecting GW 

 

35Using best professional judgment informed by deliberations within the TCRDSAC, EPA assumes that some 

systems will have 0 percent occurrence for some number of years longer than one year, and some will have 

occurrence levels that are >0 percent within the first year. The assumption used in the analysis (systems will have 1 

year with 0 percent occurrence, plus 2 to 3 years of reduced occurrence from their baseline occurrence) is meant to 

represent an average system that experiences occurrence that is between these two scenarios. 
Economic Analysis for the Final RTCR 5-21 September 2012 

systems having source water EC+ results36 will implement disinfection or nondisinfecting 

corrective action. Those adding disinfection essentially get removed from the nondisinfecting 

category and are reassigned to the disinfecting category for the remainder of the modeling 

period. The portion of systems in this subset that are assumed to implement a nondisinfecting 

corrective action37 are assumed to experience the same reduced occurrence levels as those 

addressing Level 2 Assessments (i.e., 0 percent occurrence for 2 years, then occurrence at 25 

percent of baseline for an additional 5 years). As Chapter 7 of this EA explains, no costs are 

attributed to the RTCR for any corrective action related to source water EC occurrence since 

such costs have already been considered in the GWR EA (USEPA, 2006a). 

Outputs generated from this predictive simulation model (for PWSs serving 4,100 or 

fewer people) include the following for each modeled year: occurrence of TC+ and EC+ assays, 

the number of Level 1 and Level 2 assessments conducted, and the number of Level 1 and Level 

2 corrective actions implemented. Based on these model outputs and the criteria for reduced 

monitoring, the model also provides estimates of the number of systems on monthly, quarterly, 

and annual sampling regimes (and by implication the number of routine, repeat, and additional 

routine samples taken annually) under the RTCR and Alternative option. These requirements are 

detailed in Chapter 3 of this EA.

The results of the RTCR predictive occurrence model are presented in the following 

section, Section 5.3.3.

 

36 The model determines source water occurrence separately based on the subset of nondisinfecting GW systems, as 

described in Section 5.3.1 (2nd paragraph) of this chapter. 

37 Estimates of the number of systems implementing a nondisinfection corrective action are taken from Exhibit 

6.21b ("Estimated Distribution of Source Water Contamination Corrective Actions") of the GWR EA (USEPA, 

2006a). The GWR EA estimated the number of systems choosing a nondisinfection corrective action based on a 

range; the high end was the percentage of CWS entry points employing disinfection at that time by system size, and 

the low end was assumed to be 10 percent based on discussions with state representatives. 
Economic Analysis for the Final RTCR 5-22 September 2012 

Exhibit 5.7 Simulated Impact of the RTCR and Alternative Option on Systems 

Serving ≤4,100 People—Surface Water Systems 
Economic Analysis for the Final RTCR 5-23 September 2012 

Exhibit 5.8 Simulated Impact of the RTCR and Alternative Option on Systems 

Serving ≤4,100 People—Ground Water Systems 
Economic Analysis for the Final RTCR 5-24 September 2012 

Exhibit 5.9a Percent of GW Systems Assumed to be on Monthly, Quarterly, and 

Annual (M/Q/A) Monitoring by System Category under 1989 TCR (Baseline)—

Initial Estimates (Post-GWR Implementation) 

Size

 Number of 

Systems Monthly Quarterly Annual

≤100 6,132 86.6% 13.4% 0.0%

101-1,000 12,762 88.5% 11.5% 0.0%

1,001-4,100 5,405 100.0% 0.0% 0.0%

≤100 5,806 86.6% 13.4% 0.0%

101-1,000 5,597 88.6% 11.4% 0.0%

1,001-4,100 1,038 100.0% 0.0% 0.0%

≤100 2,904 19.3% 64.7% 16.0%

101-1,000 3,621 18.5% 66.7% 14.7%

1,001-4,100 542 100.0% 0.0% 0.0%

≤100 5,913 19.3% 64.7% 16.0%

101-1,000 4,710 18.5% 66.7% 14.8%

1,001-4,100 270 100.0% 0.0% 0.0%

≤100 13,558 4.8% 62.9% 32.3%

101-1,000 6,014 7.9% 66.9% 25.2%

1,001-4,100 269 100.0% 0.0% 0.0%

≤100 46,642 4.8% 62.9% 32.3%

101-1,000 15,224 7.8% 66.8% 25.3%

1,001-4,100 348 100.0% 0.0% 0.0%

Transient, Noncommunity Water Systems (TNCWSs), Non-Disinfecting

Notes: 

 1) EPA assumes that the frequencies noted in this exhibit for the 1989 TCR would also 

apply under the RTCR in the first 10 years of the analysis period. Under the Alternative 

option, all systems would monitor monthly for the first 5 years after the RTCR effective 

date. 

2) Estimates for the size categories presented in this exhibit are produced from weighted 

averages from the following size categories (and corresponding estimates of proportion 

sampling monthly, quarterly, or annually): ≤100; 101-500; 501-1,000; 1,001-2,500; 2,501-

3,300; and 3,301-4,100. Water Type includes disinfection status, as informed by 

information from SDWIS/FED. 

3) Systems with no indication of disinfection (“Disinf?”) status in SDWIS/FED were 

assumed to not disinfect. 

4) Some figures may not add due to rounding in the model.

Community Water Systems (CWSs), Disinfecting

Community Water Systems (CWSs), Non-Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Non-Disinfecting

Transient, Noncommunity Water Systems (TNCWSs), Disinfecting
Economic Analysis for the Final RTCR 5-25 September 2012 

Exhibit 5.9b Percent of GW Systems Predicted to be on M/Q/A Monitoring by 

System Category under RTCR—Adjusted Estimates (Post-RTCR Implementation) 

Size

 Number of 

Systems Monthly Quarterly Annual

≤100 6,132 86.6% 13.4% 0.0%

101-1,000 12,762 88.5% 11.5% 0.0%

1,001-4,100 5,405 100.0% 0.0% 0.0%

≤100 5,806 86.6% 13.4% 0.0%

101-1,000 5,597 88.6% 11.4% 0.0%

1,001-4,100 1,038 100.0% 0.0% 0.0%

≤100 2,907 2.8% 89.9% 7.3%

101-1,000 3,621 2.6% 91.2% 6.3%

1,001-4,100 542 100.0% 0.0% 0.0%

≤100 5,919 14.7% 78.0% 7.3%

101-1,000 4,710 13.5% 79.9% 6.5%

1,001-4,100 270 100.0% 0.0% 0.0%

≤100 13,558 5.2% 81.0% 13.7%

101-1,000 6,014 5.1% 81.7% 13.2%

1,001-4,100 269 100.0% 0.0% 0.0%

≤100 46,642 16.9% 71.0% 12.0%

101-1,000 15,224 16.7% 71.2% 12.1%

1,001-4,100 348 100.0% 0.0% 0.0%

Transient, Noncommunity Water Systems (TNCWSs), Non-Disinfecting

Notes: 

1) M/Q/A percentage estimates are based on model predictions of acute and non-acute 

violations from years 6 – 10 (NCWSs) and 6 – 8 (CWSs) of the 30-year modeled period. 

Systems incurring 1 or more acutes or non-acutes in this period are assumed to be on 

monthly monitoring for years 11 – 25 of the analysis; the remaining systems are 

distributed between quarterly and annual monitoring according to the percentage 

distribution from the initial M/Q/A estimates (Exhibit 5.9a). Other constraints apply to the 

determination of the M/Q/A distribution of systems as described in Section 5.3.2 above. 

2) Estimates for the size categories presented in this exhibit are produced from weighted 

averages from the following size categories (and corresponding estimates of proportion 

sampling monthly, quarterly, or annually): ≤100; 101-500; 501-1,000; 1,001-2,500; 2,501-

3,300; and 3,301-4,100. 

3) Systems with no indication of disinfection (“Disinf?”) status in SDWIS/FED were 

assumed to not disinfect.

4) Some figures may not add due to rounding in the model.

Community Water Systems (CWSs), Disinfecting

Community Water Systems (CWSs), Non-Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Non-Disinfecting

Transient, Noncommunity Water Systems (TNCWSs), Disinfecting
Economic Analysis for the Final RTCR 5-26 September 2012 

Exhibit 5.9c Percent of GW Systems on M/Q/A Monitoring by System Category 

under Alternative option—Adjusted Estimates (Post-RTCR Implementation)

Size

 Number of 

Systems Monthly Quarterly Annual

≤100 6,132 86.6% 13.4% 0.0%

101-1,000 12,762 88.5% 11.5% 0.0%

1,001-4,100 5,405 100.0% 0.0% 0.0%

≤100 5,806 86.6% 13.4% 0.0%

101-1,000 5,597 88.6% 11.4% 0.0%

1,001-4,100 1,038 100.0% 0.0% 0.0%

≤100 2,907 4.4% 95.6% 0.0%

101-1,000 3,621 4.5% 95.5% 0.0%

1,001-4,100 542 100.0% 0.0% 0.0%

≤100 5,919 20.8% 79.2% 0.0%

101-1,000 4,710 21.5% 78.5% 0.0%

1,001-4,100 270 100.0% 0.0% 0.0%

≤100 13,558 9.9% 90.1% 0.0%

101-1,000 6,014 10.1% 89.9% 0.0%

1,001-4,100 269 100.0% 0.0% 0.0%

≤100 46,642 25.8% 74.2% 0.0%

101-1,000 15,224 25.4% 74.6% 0.0%

1,001-4,100 348 100.0% 0.0% 0.0%

Transient, Noncommunity Water Systems (TNCWSs), Non-Disinfecting

Notes: 

1) M/Q/A percentage estimates are based on model predictions from years 6 – 10 

(NCWSs) and 6 – 8 (CWSs) of the period of analysis. Systems incurring 1 or more 

acutes or non-acutes in this period are assumed to be on monthly monitoring for years 

11 – 25 of the analysis; the remaining systems are assumed to be on quarterly 

monitoring. Other constraints apply to the determination of the M/Q/A distribution of 

systems as described in Section 5.3.2 above. This is a modeling assumption that 

reflects an expected steady state of some systems that will regain and others that will 

lose reduced monitoring post RTCR implementation. 

2) Estimates for the size categories presented in this exhibit are produced from weighted 

averages from the following size categories (and corresponding estimates of proportion 

sampling monthly, quarterly, or annually): ≤100; 101-500; 501-1,000; 1,001-2,500; 2,501-

3,300; and 3,301-4,100. 

3) Systems with no indication of disinfection (“Disinf?”) status in SDWIS/FED were 

assumed to not disinfect.

4) Some figures may not add due to rounding in the model.

Community Water Systems (CWSs), Disinfecting

Community Water Systems (CWSs), Non-Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Disinfecting

Nontransient, Noncommunity Water Systems (NTNCWSs), Non-Disinfecting

Transient, Noncommunity Water Systems (TNCWSs), Disinfecting
Economic Analysis for the Final RTCR 5-27 September 2012 

5.3.3 Predictive Model Results 

As noted above, the predictive model produces output that includes national estimates of 

sampling and occurrence in PWSs across the United States, the resulting Level 1 and Level 2 

assessments, corrective actions resulting from Level 1 and Level 2 assessments, and reductions 

in sampling and occurrence for these systems in accordance with requirements under the 1989 

TCR, the RTCR, and the Alternative option. In Exhibits 5.10 through 5.15, output includes the 

model years 1–30 described in Section 5.3.2.2. Years 1–5 are summed for the 1989 TCR only 

and represent the period prior to the start of monitoring under the final RTCR, including 5 years 

after the GWR effective date. Year 5 in the analysis (also for just the 1989 TCR) is also shown 

separately because it represents the baseline year, reflecting conditions just prior to the start of 

monitoring under the RTCR. Model years 6 through 30 are summed for the 1989 TCR, the 

RTCR, and the Alternative option because they represent the 25-year period of analysis 

following promulgation of the RTCR. 

For all types of PWSs, the model output is presented for the 1989 TCR, the RTCR, and 

the Alternative option. The 1989 TCR with the GWR effects incorporated serves as the 

appropriate baseline for comparisons with the RTCR. 

EPA’s general expectations for TC occurrence for GW systems shown in Exhibits 5.16–

5.18 are as follows: 

1. Years 1–5 show a decline in the TC+ rates due to GWR implementation effects. 

These include expected reductions in RTTC rates for all GW systems related to SSs, 

for disinfecting GW systems related to the compliance monitoring, and for 

nondisinfecting GW systems due to corrective actions taken following a source water 

EC+ sample. 

2. Years 6–30 reflect additional reductions (beyond GWR effects) in TC+ rates due to 

the RTCR or Alternative option. The RTCR and Alternative option occurrence rates 

are generally lower than those for the 1989 TCR with the GWR primarily because of 

the additional corrective actions (Level 1 and Level 2). In some subgroups, some 

counts are higher under the Alternative option than under the 1989 TCR due to the 

increased sampling e.g., routine TC+ and routine EC+ results for GW NTNCWSs 

(Ex. 5.11). The balance of the two effects of reduced sampling (reduced additional 

and repeat samples) and the additional assessments and corrective actions, which 

move the counts in opposite directions, is explored in the sensitivity analysis in 

Section 5.3.3.1 of this chapter. 

3. In Years 6 through 10 and years 11–30 differences in TC+ rates between the RTCR 

and Alternative option are due to different proportions of systems that are performing 

monthly, quarterly, or annual monitoring. In general, more monitoring (e.g., more 

systems doing monthly than quarterly, or more systems doing quarterly than 

annual)—in conjunction with the corrective actions—will push the TC occurrence 

levels down (more samples are expected to be taken and fewer samples are likely to 

be positive). 
Economic Analysis for the Final RTCR 5-28 September 2012 

a. In years 6–10, the Alternative option has a lower TC+ rate than the RTCR 

because all systems under the Alternative option begin the 5-year period on 

monthly sampling. The increased sampling and resulting increase in corrective 

actions performed will together reduce the occurrence rate. 

b. By year 11, the systems are sampling according to their “steady state” 

regimens, when all of the systems that qualified for reduced monitoring during 

their respective periods of assessment (as described in Section 5.3.2.2) are 

assigned to their reduced regimens in the model. For the RTCR, the 

proportions of systems on M/Q/A sampling is identical to those under the 

1989 TCR; under the Alternative option, however, systems that would qualify 

under the 1989 TCR for annual monitoring can only reduce to quarterly 

monitoring. 

The following paragraphs describe TC occurrence in PWSs serving less than or equal to 

4,100 people (as shown in Exhibits 5.16 through 5.21). See Appendix B for detailed breakouts of 

TC occurrence by population category. 

In Exhibit 5.16 (GW CWSs), the graph shows the expected drop in TC rates for years 1–5 

as the GWR is implemented prior to RTCR. There are only very small differences between the 

RTCR and Alternative option, and these are not observable in this graph. A comparison of the 

estimates in Exhibit 5.10 clarifies these small differences. Most of these systems are already on 

monthly sampling, so there is no significant difference seen between the RTCR and Alternative 

option in years 6–8 for those few systems not on monthly sampling and it is assumed that the 

monthly/quarterly distribution after this period returns to that under the 1989 TCR. Therefore, 

the TC+ rates over the 25-year period for these systems show no difference between the RTCR 

and Alternative option. 

In Exhibit 5.17 (GW NTNCWSs), the graph also shows the expected drop in TC+ rates 

for years 1–5 as the GWR is implemented prior to the RTCR. For years 6–10 the occurrence 

rates decrease under the RTCR and the Alternative option due to the implementation of 

corrective actions, and the rates for the Alternative option are lower than for the RTCR since all 

systems are on monthly sampling under the Alternative option for this period (having the effect 

of reducing the occurrence level as noted above). However, from year 11 to 30, the M/Q/A 

distributions for these two are essentially the same and therefore the TC occurrence levels are the 

same over this period. 

In Exhibit 5.18 (GW TNCWS), the graph also shows the expected drop in TC+ rates for 

years 1–5 as the GWR is implemented prior to the RTCR. For years 6–10, the TC rates drop 

further as the corrective actions implemented in response to Level 1 and Level 2 assessments are 

begun for both the RTCR and Alternative option. TC occurrence is markedly lower during this 

period for the Alternative option where all systems are on monthly monitoring, whereas the 

majority of systems under the RTCR are on quarterly monitoring. Beginning in Year 11, there is 

a shift under the RTCR towards more systems on monthly monitoring than under the 1989 TCR, 

and more systems on quarterly monitoring than under the 1989 TCR, and hence the overall TC+ 

rate drops. For the Alternative option, beginning in Year 11, a substantial portion of systems 

move from the all monthly sampling during years 6–10 to quarterly sampling (but none on 
Economic Analysis for the Final RTCR 5-29 September 2012 

annual sampling). Because there are slightly more systems under the Alternative option that end 

up on monthly and quarterly monitoring than under the RTCR for years 11–30, the TC+ rate for 

the RTCR is slightly higher than for the Alternative option. 

EPA’s general expectations for TC+ rates for SW systems shown in Exhibits 5.19–5.21 

are as follows: 

1. The 1989 TCR is provided as the baseline for comparison with the RTCR (the GWR 

does not apply to SW systems and therefore its effect is not included in these graphs). 

2. Because all SW systems of all sizes do monthly monitoring (no systems are on 

quarterly or annual monitoring), the applicable provisions of the RTCR are identical 

for the RTCR and Alternative option. 

3. The reductions in TC+ rates shown by the RTCR relative to the 1989 TCR therefore 

reflect solely the effects of the corrective actions implemented in response to Level 1 

and Level 2 assessments. 

In Exhibit 5.19 (SW CWSs), the graph shows little difference in TC+ rates between the 

1989 TCR and RTCR. This is primarily because the current TC+ rate is very low for these 

systems, and therefore there are few corrective actions implemented over the 25-year period. 

In Exhibit 5.20 (SW NTNCWSs), the graph shows that there is a slightly greater 

difference between the 1989 TCR and the RTCR for the SW NTNCWSs than for the SW CWSs 

shown in Exhibit 5.19. This is because the baseline TC+ rate is slightly higher and, therefore, 

more corrective actions are performed for SW NTNCWSs than SW CWSs. 

In Exhibit 5.21 (SW TNCWSs), the graph indicates that this group exhibits the most 

significant difference between the 1989 TCR and RTCR since the baseline TC+ rate for these 

systems is approximately twice that of the SW NTNCWSs and SW CWSs. 

A comparison of results for SW versus GW systems reveals a pattern of lower occurrence 

for SW systems; this is explained by the uniform requirement that SW systems disinfect. Many 

GW systems are not required to disinfect, and the result is a level of TC occurrence that is 

periodically elevated in some systems, raising the overall average TC occurrence in GW system 

categories. This difference is larger for the GW NCWSs than for the GW CWSs based on the 

relatively large proportion of GW NCWSs that do not disinfect. The difference is largest among 

the TNCWSs, a category in which the largest proportion of GW systems do not disinfect. 

Complete results from the model (by year and system size) and additional graphs are 

shown in Appendix B. The implications of these results in terms of changes in the level of risk 

associated with contamination of PWS water supplies are discussed in Chapter 6 of this EA. 

Model results are used to calculate national estimates of the net change in costs for PWSs in 

Chapter 7 of this EA. 
Economic Analysis for the Final RTCR 5-30 September 2012 

Exhibit 5.10 Ground Water Community Water System Model Output Cumulative Endpoints 

Period

Regulatory 

Scenario

Routine 

Samples

Additional 

Routine 

Samples

Repeat 

Samples

GWR 

Source 

Water 

Samples

Routine 

TC+ 

Samples

Repeat 

TC+ 

Samples

Routine 

E. coli + 

Samples

Repeat 

E. coli + 

Samples

GWR 

E. coli + 

Samples

NonAcute 

Events

Acute 

Events

Level 1 

Assessments

Level 2 

Assessments

Level 1 

Corrective 

Actions

Level 2 

Corrective 

Actions

GWR, NonDisinfecting 

Systems1

GWR, 

Disinfecting 

Systems2

1989 TCR No GWR 12,712,859 1,052,957 816,079 0 215,787 111,640 10,267 4,344 0 55,639 5,773 34,556 30,657 0 0 0 0

1989 TCR 12,761,616 864,605 588,252 93,331 176,379 66,797 7,236 2,106 872 39,769 3,335 26,947 18,545 0 0 714 158

RTCR 12,984,469 19,027 488,523 83,140 162,841 48,053 6,438 1,347 816 30,271 2,362 22,112 11,667 2,220 1,155 665 151

Alternative Option 13,073,297 16,686 490,683 83,299 163,561 47,829 6,562 1,595 781 29,955 2,511 21,917 11,660 2,242 1,175 622 160

1989 TCR No GWR 2,542,182 254,662 197,228 0 52,150 27,053 2,471 1,033 0 13,486 1,391 8,410 7,393 0 0 0 0

1989 TCR 2,550,295 180,676 122,391 19,799 36,791 14,208 1,532 460 312 8,358 711 5,542 4,103 0 0 203 109

1989 TCR No GWR 508,401 42,520 32,969 0 8,719 4,613 402 176 0 2,259 240 1,415 1,241 0 0 0 0

1989 TCR 510,266 35,345 24,060 3,864 7,231 2,655 297 70 48 1,605 130 1,107 731 0 0 31 17

Sum Years 

6-30

Sum Years 

1-5

Source: RTCR predictive model.

Note: Years 1 – 5 in the model reflect incorporation of GWR effects (explained in Section 5.3.3) into pre-GWR baseline data; Year 5 in the model reflects baseline conditions immediately prior to the effective date of the RTCR; and Years 6 – 30 represent a 

period of 25 years after monitoring begins under the RTCR.

1Number of Non-Disinfecting GWR Systems with an E. coli + remaining as Non-Disinfecting Systems.

2Number of Non-Disinfecting GWR Systems with an E. coli + changing to Disinfecting Systems.

Year 5

Exhibit 5.11 Ground Water Nontransient Noncommunity Water System Model Output Cumulative Endpoints 

Period

Regulatory 

Scenario

Routine 

Samples

Additional 

Routine 

Samples

Repeat 

Samples

GWR 

Source 

Water 

Samples

Routine 

TC+ 

Samples

Repeat 

TC+ 

Samples

Routine 

E. coli + 

Samples

Repeat 

E. coli + 

Samples

GWR

E. coli + 

Samples

NonAcute 

Events

Acute 

Events

Level 1 

Assessments

Level 2 

Assessments

Level 1 

Corrective 

Actions

Level 2 

Corrective 

Actions

GWR, NonDisinfecting 

Systems1

GWR, 

Disinfecting 

Systems2

1989 TCR No GWR 2,661,114 328,889 264,574 0 68,232 59,455 3,484 2,338 0 24,614 2,723 14,759 14,021 0 0 0 0

1989 TCR 2,668,723 271,756 178,204 42,339 55,965 34,716 2,534 1,269 446 17,922 1,778 11,658 8,991 0 0 351 95

RTCR 2,564,440 90,884 145,401 37,384 48,467 25,164 2,115 841 435 13,642 1,213 10,157 5,088 1,015 499 350 85

Alternative Option 3,345,137 71,729 185,814 48,181 61,938 31,758 2,628 1,089 496 17,403 1,547 11,996 7,585 1,194 761 389 107

1989 TCR No GWR 532,239 66,134 53,191 0 13,714 11,904 693 446 0 4,925 531 2,956 2,794 0 0 0 0

1989 TCR 533,205 58,599 38,489 9,192 12,094 7,867 574 288 150 3,924 403 2,477 2,084 0 0 99 52

1989 TCR No GWR 106,453 13,330 10,711 0 2,760 2,425 137 89 0 1,001 102 603 555 0 0 0 0

1989 TCR 106,725 10,980 7,219 1,717 2,267 1,416 95 48 23 729 68 473 362 0 0 16 6

Sum Years 

1-5

Source: RTCR predictive model.

Note: Years 1 – 5 in the model reflect incorporation of GWR effects (explained in Section 5.3.3) into pre-GWR baseline data; Year 5 in the model reflects baseline conditions immediately prior to the effective date of the RTCR; and Years 6 – 30 represent a 

period of 25 years after monitoring begins under the RTCR.

1Number of Non-Disinfecting GWR Systems with an E. coli + remaining as Non-Disinfecting Systems.

2Number of Non-Disinfecting GWR Systems with an E. coli + changing to Disinfecting Systems.

Sum Years 

6-30

Year 5
Economic Analysis for the Final RTCR 5-31 September 2012 

Exhibit 5.12 Ground Water Transient Noncommunity Water System Model Output Cumulative Endpoints 

Period

Regulatory 

Scenario

Routine 

Samples

Additional 

Routine 

Samples

Repeat 

Samples

GWR 

Source 

Water 

Samples

Routine 

TC+ 

Samples

Repeat 

TC+ 

Samples

Routine 

E. coli + 

Samples

Repeat 

E. coli + 

Samples

GWR 

E. coli + 

Samples

NonAcute 

Events

Acute 

Events

Level 1 

Assessments

Level 2 

Assessments

Level 1 

Corrective 

Actions

Level 2 

Corrective 

Actions

GWR, NonDisinfecting 

Systems1

GWR, 

Disinfecting 

Systems2

1989 TCR No GWR 7,508,835 1,766,220 1,489,330 0 374,523 373,849 17,881 14,195 0 143,238 15,757 87,899 79,745 0 0 0 0

1989 TCR 7,524,239 1,458,180 966,919 253,032 305,814 213,958 12,859 7,416 2,651 105,646 10,326 70,031 51,552 0 0 2,134 517

RTCR 9,780,374 674,328 981,521 283,807 327,174 191,401 13,121 5,792 2,993 99,961 8,421 71,817 39,668 7,188 4,039 2,455 538

Alternative Option 14,651,904 528,324 1,379,719 398,642 459,906 258,975 18,354 7,963 3,622 135,781 11,760 87,063 66,458 8,498 6,564 3,012 610

1989 TCR No GWR 1,501,831 350,417 295,149 0 74,227 73,576 3,577 2,709 0 28,251 3,150 17,357 15,692 0 0 0 0

1989 TCR 1,503,848 311,414 206,844 54,227 65,441 47,969 2,873 1,791 942 22,651 2,360 14,769 11,528 0 0 610 332

1989 TCR No GWR 300,376 70,103 59,023 0 14,844 14,766 686 612 0 5,627 610 3,545 3,008 0 0 0 0

1989 TCR 300,923 59,747 39,565 10,447 12,536 8,813 506 331 129 4,269 429 2,821 2,101 0 0 87 42

Source: RTCR predictive model.

Note: Years 1 – 5 in the model reflect incorporation of GWR effects (explained in Section 5.3.3) into pre-GWR baseline data; Year 5 in the model reflects baseline conditions immediately prior to the effective date of the RTCR; and Years 6 – 30 represent a 

period of 25 years after monitoring begins under the RTCR.

1Number of Non-Disinfecting GWR Systems with an E. coli + remaining as Non-Disinfecting Systems.

2Number of Non-Disinfecting GWR Systems with an E. coli + changing to Disinfecting Systems.

Year 5

Sum Years 

6-30

Sum Years 

1-5

Exhibit 5.13 Surface Water Community Water System Model Output Cumulative Endpoints 

Period

Regulatory 

Scenario

Routine 

Samples

Additional 

Routine 

Samples

Repeat 

Samples

GWR 

Source 

Water 

Samples

Routine 

TC+ 

Samples

Repeat 

TC+ 

Samples

Routine 

E. coli + 

Samples

Repeat 

E. coli + 

Samples

GWR 

E. coli + 

Samples

NonAcute 

Events

Acute 

Events

Level 1 

Assessments

Level 2 

Assessments

Level 1 

Corrective 

Actions

Level 2 

Corrective 

Actions

GWR, NonDisinfecting 

Systems1

GWR, 

Disinfecting 

Systems2

1989 TCR 3,516,224 137,063 98,139 0 27,729 5,244 2,909 293 0 3,322 666 2,829 1,237 0 0 0 0

RTCR 3,565,200 0 81,187 0 27,062 3,860 2,866 180 0 2,755 502 2,415 901 243 93 0 0

Alternative 

Option 3,565,200 0 81,187 0 27,062 3,860 2,866 180 0 2,755 502 2,415 901 243 93 0 0

Sum Years 

1-5 1989 TCR 703,236 27,458 19,651 0 5,550 1,066 584 57 0 675 137 573 255 0 0 0 0

Year 5 1989 TCR 140,622 5,559 3,956 0 1,117 224 119 13 0 138 29 115 55 0 0 0 0

Sum Years 

6-30

Source: RTCR predictive model.

Note: Years 1 – 5 in the model reflect incorporation of GWR effects (explained in Section 5.3.3) into pre-GWR baseline data; Year 5 in the model reflects baseline conditions immediately prior to the effective date of the RTCR; and Years 6 – 30 

represent a period of 25 years after monitoring begins under the RTCR.

1Number of Non-Disinfecting GWR Systems with an E. coli + remaining as Non-Disinfecting Systems.

2Number of Non-Disinfecting GWR Systems with an E. coli + changing to Disinfecting Systems.
Economic Analysis for the Final RTCR 5-32 September 2012 

Exhibit 5.14 Surface Water Nontransient Noncommunity Water System Model Output Cumulative Endpoints 

Period

Regulatory 

Scenario

Routine 

Samples

Additional 

Routine 

Samples

Repeat 

Samples

GWR 

Source 

Water 

Samples

Routine 

TC+ 

Samples

Repeat 

TC+ 

Samples

Routine 

E. coli + 

Samples

Repeat 

E. coli + 

Samples

GWR

E. coli + 

Samples

NonAcute 

Events

Acute 

Events

Level 1 

Assessments

Level 2 

Assessments

Level 1 

Corrective 

Actions

Level 2 

Corrective 

Actions

GWR, NonDisinfecting 

Systems1

GWR, 

Disinfecting 

Systems2

1989 TCR 222,494 13,728 10,670 0 2,796 1,127 360 51 0 458 105 292 294 0 0 0 0

RTCR 225,900 0 8,183 0 2,728 675 350 37 0 330 76 232 187 24 19 0 0

Alternative 

Option 225,900 0 8,183 0 2,728 675 350 37 0 330 76 232 187 24 19 0 0

Sum Years 

1-5

1989 TCR 

44,500 2,740 2,131 0 558 221 72 10 0 90 21 57 59 0 0 0 0

Year 5 1989 TCR 8,898 554 429 0 113 43 15 2 0 17 4 11 12 0 0 0 0

Sum Years 

6-30

Source: RTCR predictive model.

Note: Years 1 – 5 in the model reflect incorporation of GWR effects (explained in Section 5.3.3) into pre-GWR baseline data; Year 5 in the model reflects baseline conditions immediately prior to the effective date of the RTCR; and Years 6 – 30 

represent a period of 25 years after monitoring begins under the RTCR.

1Number of Non-Disinfecting GWR Systems with an E. coli + remaining as Non-Disinfecting Systems.

2Number of Non-Disinfecting GWR Systems with an E. coli + changing to Disinfecting Systems.

Exhibit 5.15 Surface Water Transient Noncommunity Water System Model Output Cumulative Endpoints 

Period

Regulatory 

Scenario

Routine 

Samples

Additional 

Routine 

Samples

Repeat 

Samples

GWR 

Source 

Water 

Samples

Routine 

TC+ 

Samples

Repeat 

TC+ 

Samples

Routine 

E. coli + 

Samples

Repeat 

E. coli + 

Samples

GWR 

E. coli + 

Samples

NonAcute 

Events

Acute 

Events

Level 1 

Assessments

Level 2 

Assessments

Level 1 

Corrective 

Actions

Level 2 

Corrective 

Actions

GWR, NonDisinfecting 

Systems1

GWR, 

Disinfecting 

Systems2

1989 TCR 609,514 71,280 57,424 0 14,612 8,365 1,855 398 0 3,148 765 1,893 2,214 0 0 0 0

RTCR 625,200 0 39,905 0 13,302 4,311 1,679 218 0 2,037 437 1,357 1,200 130 118 0 0

Alternative 

Option 625,200 0 39,905 0 13,302 4,311 1,679 218 0 2,037 437 1,357 1,200 130 118 0 0

Sum Years 

1-5 1989 TCR 

121,900 14,265 11,476 0 2,920 1,671 382 81 0 628 152 370 449 0 0 0 0

Year 5 1989 TCR 24,373 2,891 2,314 0 589 331 77 17 0 124 30 74 88 0 0 0 0

Source: RTCR predictive model.

Note: Years 1 – 5 in the model reflect incorporation of GWR effects (explained in Section 5.3.3) into pre-GWR baseline data; Year 5 in the model reflects baseline conditions immediately prior to the effective date of the RTCR; and Years 6 – 30 

represent a period of 25 years after monitoring begins under the RTCR.

1Number of Non-Disinfecting GWR Systems with an E. coli + remaining as Non-Disinfecting Systems.

2Number of Non-Disinfecting GWR Systems with an E. coli + changing to Disinfecting Systems.

Sum Years 

6-30
Economic Analysis for the Final RTCR 5-33 September 2012 

Exhibit 5.16 Ground Water Community Water System 

(Serving ≤ 4,100) TC Occurrence 

Source: RTCR Predictive Model 

Notes: 

1) 1989 TCR No GWR: Represents the predicted TC occurrence, absent the effects of GWR 

implementation, under the 1989 TCR requirements. 

2) 1989 TCR: Represents the projected TC occurrence under the 1989 TCR requirements, including the 

effects of GWR implementation. 

3) RTCR: Represents the projected TC occurrence under RTCR requirements, including the effects of 

GWR implementation. 

4) Alt Option: Represents the projected TC occurrence under the Alternative option requirements, 

including the effects of GWR implementation. 

5) Steady state: By Year 11, all systems that qualify for reduced monitoring during their assessment period 

(Section 5.3.2.2) have moved to their reduced sampling schedule under the RTCR and Alternative 

option. This period in the model (from years 11–30) reflects a steady state with regard to proportions of 

systems sampling on monthly, quarterly, or annual regimens. 
Economic Analysis for the Final RTCR 5-34 September 2012 

Exhibit 5.17 Ground Water Nontransient Noncommunity Water System 

(Serving ≤ 4,100) TC Occurrence 

Source: RTCR Predictive Model 

Notes: 

1) 1989 TCR No GWR: Represents the predicted TC occurrence, absent the effects of GWR 

implementation, under the 1989 TCR requirements. 

2) 1989 TCR: Represents the projected TC occurrence under the 1989 TCR requirements, including the 

effects of GWR implementation. 

3) RTCR: Represents the projected TC occurrence under RTCR requirements, including the effects of 

GWR implementation. 

4) Alt Option: Represents the projected TC occurrence under the Alternative option requirements, including 

the effects of GWR implementation. 

5) Steady state: By Year 11, all systems that qualify for reduced monitoring during their assessment period 

(Section 5.3.2.2) have moved to their reduced sampling schedule under the RTCR and Alternative 

option. This period in the model (from years 11–30) reflects a steady state with regard to proportions of 

systems sampling on monthly, quarterly, or annual regimens.
Economic Analysis for the Final RTCR 5-35 September 2012 

Exhibit 5.18 Ground Water Transient Noncommunity Water System 

(Serving ≤ 4,100) TC Occurrence 

Source: RTCR Predictive Model 

Notes: 

1) 1989 TCR No GWR: Represents the predicted TC occurrence, absent the effects of GWR 

implementation, under the 1989 TCR requirements. 

2) 1989 TCR: Represents the projected TC occurrence under the 1989 TCR requirements, including the 

effects of GWR implementation. 

3) RTCR: Represents the projected TC occurrence under RTCR requirements, including the effects of 

GWR implementation. 

4) Alt Option: Represents the projected TC occurrence under the Alternative option requirements, 

including the effects of GWR implementation. 

5) Steady state: By Year 11, all systems that qualify for reduced monitoring during their assessment period 

(Section 5.3.2.2) have moved to their reduced sampling schedule under the RTCR and Alternative 

option. This period in the model (from years 11–30) reflects a steady state with regard to proportions of 

systems sampling on monthly, quarterly, or annual regimens. 
Economic Analysis for the Final RTCR 5-36 September 2012 

Exhibit 5.19 Surface Water Community Water System 

(Serving ≤ 4,100) TC Occurrence 

Source: RTCR Predictive Model 

Notes: 

1) 1989 TCR: Represents the projected TC occurrence under the 1989 TCR requirements. 

2) RTCR and Alt Option: Represents the projected TC occurrence under the RTCR and Alternative option, 

which have the same requirements for SW systems, resulting in the same TC occurrence under the two 

options. 
Economic Analysis for the Final RTCR 5-37 September 2012 

Exhibit 5.20 Surface Water Nontransient Noncommunity Water System 

(Serving ≤ 4,100) TC Occurrence 

Source: RTCR Predictive Model 

Notes: 

1) 1989 TCR: Represents the projected TC occurrence under the 1989 TCR requirements, which 

compose the baseline regulatory option for the RTCR EA. 

2) RTCR and Alt Option: Represents the projected TC occurrence under the RTCR and Alternative option, 

which have the same requirements for SW systems, resulting in the same TC occurrence under the two 

options. 
Economic Analysis for the Final RTCR 5-38 September 2012 

Exhibit 5.21 Surface Water Transient Noncommunity Water System 

(Serving ≤ 4,100) TC Occurrence 

Source: RTCR Predictive Model 

Notes: 

1) 1989 TCR: Represents the projected TC occurrence under the 1989 TCR requirements. 

2) RTCR and Alt Option: Represents the projected TC occurrence under the RTCR and Alternative option, 

which have the same requirements for SW systems, resulting in the same TC occurrence under the two 

options. 
Economic Analysis for the Final RTCR 5-39 September 2012

5.3.3.1 Uncertainty and Sensitivity Analysis in Occurrence Modeling

There are two primary sources of uncertainty in the RTCR occurrence modeling: 

uncertainty related to the baseline occurrence model due to the limited data on which the model 

is based, and uncertainty regarding the frequency and effectiveness of corrective actions and 

their effects on subsequent TC and EC occurrence. 

Data limitations in part derive from a lack of observed data on the effects of the 

requirements of the GWR, for which implementation began as of December 2009. In the absence 

of this data, EPA made assumptions regarding the effectiveness of each of the relevant 

requirements, as described in Section 5.3.1 of this chapter. Each of these assumptions affects the 

modeled 1989 TCR, which is the baseline for this EA. The predictive model uses this same 

baseline (1989 TCR) in determining the net influence of both the RTCR and Alternative option

requirements on occurrence. Therefore, although the actual reductions in occurrence resulting

from GWR implementation may differ from the assumptions used in this model, this difference 

would likely not affect the net results of the RTCR and Alternative option relative to the 1989 

TCR, or their performance relative to each other. Other data limitations are discussed in Section 

4.2 of this EA. 

Many other assumptions incorporated into the predictive model also have no net effect on 

results. More generally, assumptions that contribute to uncertainty in the predictive model results 

can be separated into two categories: those that have no net effect on results and those that may 

bias results downward or upward. Exhibit 5.22a below presents assumptions that influence the 

baseline (1989 TCR) and the RTCR and Alternative option in the same way, and therefore are 

expected to have no significant effect on net results. Exhibit 5.22b presents those assumptions 

that may have a significant effect on net results because they influence only the RTCR and 

Alternative option, but not the 1989 TCR. Exhibits 5.22a and 5.22b also include EPA’s best 

estimate of whether the assumption would tend to overestimate, underestimate, or have an 

unknown impact. 

Based on a lack of empirical data, EPA did not include in the model an estimate for the 

number of systems that might be required to return to more frequent monitoring after having 

been operating on a reduced schedule. A result of more frequent monitoring when combined 

with assessments and corrective actions as required under the RTCR (or Alternative option), as 

described elsewhere in this chapter, is expected to be an increase in TC and EC hits, and a 

corresponding increase in assessments and corrective actions, resulting in improved water 

quality. EPA expects that the result of not accounting for movement of systems back to a more 

rigorous monitoring schedule will tend to underestimate benefits and costs for the RTCR and 

Alternative option relative to the 1989 TCR. It may have more of an impact on net results for the 

RTCR than for the Alternative option because the RTCR is expected to have a larger proportion 

of systems on more reduced monitoring.
Economic Analysis for the Final RTCR 5-40 September 2012

Exhibit 5.22a Summary of Model Parameters Influencing 1989 TCR, RTCR, and Alternative Option

Model Parameter Current 

Assumption

Section with 

Full 

Discussion

Contributes 

Variability, 

Uncertainty, 

or Constant?

Most Likely Effect on Benefits1 Most Likely Effect on Costs1

Underestimate Overestimate Unknown 

Impact Underestimate Overestimate Unknown Impact

Distribution of systems 

across sampling 

frequency categories 

(M/Q/A) following 

implementation of GWR 

sanitary surveys prior to 

RTCR implementation

Varies per system 

category as shown 

in Ex. 5.9a

5.3.2.2 Variability,

Uncertainty

No No X No No X

Alpha, beta parameters 

developed as model 

inputs describing 

distribution of occurrence 

based on Six Year 

Review 2 Data 

(conducted in 2005)

Varies per system 

category as shown 

in Ex. 5.5–5.6

Appendix F Variability,

Uncertainty

No No X No No X

Pwell—the portion of 

ground water systems

having viral pathogens in 

their source waters 

(adopted from GWR EA)

21.58 percent 5.3.1 Constant, 

Uncertainty

No No X No No X

Psample—the probability 

that a random sample will 

test positive for viral 

pathogens given a 

contaminated source 

water (adopted from 

GWR EA)

Variable drawn from 

a beta distribution 

with a range of alpha 

and beta estimates 

having a median 

value of 5.8 percent

and an expected 

value of 12.4

percent.

5.3.1 Variability,

Uncertainty

No No X No No X
Economic Analysis for the Final RTCR 5-41 September 2012

Model Parameter Current 

Assumption

Section with 

Full 

Discussion

Contributes 

Variability, 

Uncertainty, 

or Constant?

Most Likely Effect on Benefits1 Most Likely Effect on Costs1

Underestimate Overestimate Unknown 

Impact Underestimate Overestimate Unknown Impact

Reduced occurrence for 

sanitary surveys 

performed under the 

GWR. 

90 percent of 

baseline occurrence; 

applied to equal 

number of systems 

annually over the 

sanitary survey cycle 

(20 percent each 

year of 5 years for 

CWSs; 33.3 percent

each year for 3 

years for NCWSs)

5.3.1 Constant, 

Uncertainty

No No X No No X

Reduced occurrence for 

GWR compliance 

monitoring (applies to 

subset of GW systems

that disinfect).

90 percent of 

baseline occurrence

5.3.1 Constant, 

Uncertainty

No No X No No X

Percentage of 

nondisinfecting GW

systems choosing 

disinfection corrective 

action vs. nondisinfection 

corrective action in 

response to source water 

quality issue (adopted 

from GWR)

Range: High end is 

the percentage of 

CWS entry points 

employing 

disinfection by 

system size, low end 

assumed to be 10

percent based on 

discussions with 

state 

representatives.

5.3.1 Constant, 

Uncertainty

No No X No No X

Seasonal variation in TC 

occurrence.

TC occurrence is

constant over the 

course of the year.

5.3.3.1 Variability, 

Uncertainty

No No X No No X
Economic Analysis for the Final RTCR 5-42 September 2012 

Model Parameter Current 

Assumption

Section with 

Full 

Discussion

Contributes 

Variability, 

Uncertainty, 

or Constant?

Most Likely Effect on Benefits1 Most Likely Effect on Costs1

Underestimate Overestimate Unknown 

Impact Underestimate Overestimate Unknown Impact

RTTC rate in the months

following TC+ not 

resulting in corrective 

action

RTTC rate will 

change to reflect 

either worsening of 

the problem or 

improvement based 

on actions taken 

(other than the

corrective actions 

being considered).

This was modeled

by selecting at 

random a different 

pRTTC value.

5.3.2.2 Variability, 

Uncertainty

No No X No No X

Note: For variables or factors that were incorporated into the predictive model in the same way for the 1989 TCR (baseline option) and the other two regulatory options 

considered in this EA (RTCR and Alternative Option), EPA expects that any under- or overestimation would affect the baseline and other options equally, resulting in no net 

effect on the results of the analysis. 
Economic Analysis for the Final RTCR 5-43 September 2012

Exhibit 5.22b Summary of Model Parameters Influencing RTCR and Alternative option Only

Model Parameter Current 

Assumption

Section with 

Full 

Discussion

Contributes 

Variability, 

Uncertainty, 

or Constant?

Most Likely Effect on Benefits1 Most Likely Effect on Costs1

Underestimate Overestimate Unknown 

Impact Underestimate Overestimate Unknown Impact

Percentage of systems 

implementing an Effective 

corrective action after a 

Level 1 or Level 2

Assessment 

10 percent 5.3.3.1 Constant, 

Uncertainty

X No No X No No

Occurrence immediately 

following corrective action

implementation for period 

of 3 or 5 years (Level 1 

and 2, respectively) (or 

nondisinfecting GW

systems choosing a 

nondisinfection corrective 

action)

0 percent 5.3.3.1 Constant, 

Uncertainty

No X No X No No

Duration of initial phase of 

reduced occurrence (0

percent) following 

corrective action

implementation 

Remainder of year 

+ 1 or 2 years 

(Level 1 and 2, 

respectively)

5.3.3.1 Constant, 

Uncertainty

No No X No No X

Occurrence in second 

phase following corrective 

action implementation 

(after initial phase of 0

percent occurrence)

50 percent or 25

percent of baseline 

occurrence

(Level 1 and 2, 

respectively)

5.3.3.1 Constant, 

Uncertainty

No No X No No X

Duration of reduced 

occurrence in second 

phase following corrective 

action implementation

3 or 5 years 

(Level 1 and 2, 

respectively)

5.3.3.1 Constant, 

Uncertainty

No No X No No X
Economic Analysis for the Final RTCR 5-44 September 2012

Model Parameter Current 

Assumption

Section with 

Full 

Discussion

Contributes 

Variability, 

Uncertainty, 

or Constant?

Most Likely Effect on Benefits1 Most Likely Effect on Costs1

Underestimate Overestimate Unknown 

Impact Underestimate Overestimate Unknown Impact

Duration of reduced 

occurrence (0 percent) in 

initial phase following 

corrective action

implementation (applies 

to nondisinfecting GW

systems choosing 

nondisinfecting corrective 

action)

Remainder of year 

+ 2 years 

5.3.3.1 Constant, 

Uncertainty

No No X No No X

Occurrence in second 

phase following corrective 

action implementation 

(after initial phase of 0

percent occurrence) 

(applies to nondisinfecting 

GW systems choosing 

nondisinfecting corrective 

action)

25 percent of 

baseline 

occurrence

5.3.1 Constant, 

Uncertainty

No No X No No X

Duration of reduced 

occurrence in second 

phase following corrective 

action implementation 

(applies to nondisinfecting 

GW systems choosing 

nondisinfecting corrective 

action)

5 years 5.3.2.2 Constant, 

Uncertainty

No No X No No X
Economic Analysis for the Final RTCR 5-45 September 2012 

Model Parameter Current 

Assumption

Section with 

Full 

Discussion

Contributes 

Variability, 

Uncertainty, 

or Constant?

Most Likely Effect on Benefits1 Most Likely Effect on Costs1

Underestimate Overestimate Unknown 

Impact Underestimate Overestimate Unknown Impact

For systems serving more 

than 4,100 people:

Application of a rate that 

varies by type of system 

and water source but is 

held constant through 

time (does not change 

over the 25 years of 

analysis) 

These groups incur 

the same number 

of violations 

annually throughout 

the analysis (i.e., 

no reduction in 

violations in the 

years immediately 

following corrective 

action). The

number of 

violations is used to 

calculate the 

number of Level 1 

and Level 2 

assessments and 

corrective actions 

by PWS category 

that systems will 

implement under 

the 1989 TCR, 

RTCR, and 

Alternative option.

5.4.3 Variability, 

Uncertainty

No No X No No X

Note: For variables and factors that affect the options considered (RTCR and Alternative option) but do not have a parallel influence on the 1989 TCR (baseline), EPA expects 

that any under- or over-estimation will have an effect as noted in the above exhibit on the net results for the RTCR or Alternative option.
Economic Analysis for the Final RTCR 5-46 September 2012 

Key Factors Driving Analysis Uncertainty 

The remainder of this section focuses on those assumptions identified in Exhibit 5.22b as 

contributing the most uncertainty to the net results of the analysis: the frequency and 

effectiveness of corrective actions (i.e., percent reduction in occurrence and duration of reduction 

period resulting from corrective actions) applied in the predictive model. These are the key 

drivers in determining net results, that is, the difference between the RTCR or Alternative option 

and the 1989 TCR. 

As described previously in Section 5.3, EPA incorporated the following assumptions for 

the frequency and effectiveness of the corrective actions that systems will implement following a 

Level 1 or a Level 2 assessment: 

Level 1: Following a Level 1 Assessment in a particular year, 10 percent of the systems 

performing the assessment will implement corrective actions that will reduce the TC and EC 

occurrence levels to 0 percent for the remainder of that year and for 1 full year after that. Then, 

for an additional 3 full years, the TC and EC occurrence levels for each of these systems will be 

reduced to 50 percent of their initial values. After that, the TC and EC occurrence levels return to 

their initial values. 

Level 2: Following a Level 2 Assessment in a particular year, 10 percent of the systems 

performing the assessment will implement corrective actions that will reduce the TC and EC 

occurrence levels to 0 percent for the remainder of that year and for 2 full years after that. Then, 

for an additional 5 full years, the TC and EC occurrence levels for each of these systems will be 

reduced to 25 percent of their initial values. After that, the TC and EC occurrence levels return to 

their initial values. 

Also, for the nondisinfecting GW systems that are found in the simulation to have an 

EC+ in their source water but do not move to disinfection, the assumptions for the effectiveness 

of the nondisinfecting corrective actions are identical to those above for Level 2 corrective 

actions. (However, note that all nondisinfecting systems that discover EC+ source water that do 

not go to disinfection will implement these corrective actions (under GWR), not just 10 percent 

as assumed for systems that already disinfect.) 

To assess the influence of these assumptions on the model results, EPA ran the model 

with alternative assumptions reflecting corrective actions that are less effective (50 percent of the 

assumption of efficacy in the primary analysis in this EA) and corrective actions that are more 

effective (2x the assumption of efficacy in the primary analysis). The assumptions made in the 

primary analysis, and the alternative assumptions made in this sensitivity analysis, do not 

represent a sum of the effectiveness of all individual corrective actions, but indicate the average 

frequency across all systems with which a given system will correctly diagnose and effectively 

implement a corrective action, mitigating the source of the problem. The alternative assumptions 

assume this frequency will be half or twice that used in the primary analysis. Using these 

alternative assumptions, key model outputs that can serve as proxy indicators of the costs and 

benefits of the RTCR were compared with those same outputs from the main model assumptions 

for the RTCR.
Economic Analysis for the Final RTCR 5-47 September 2012 

For the less effective corrective actions, the alternative assumptions for Level 1 and Level 

2 are: 

Level 1: Following a Level 1 Assessment in a particular year, 5 percent of the systems 

performing the assessment will implement corrective actions that reduce the TC and EC 

occurrence levels to 0 percent for the remainder of that year only. Then, for an additional 2 full 

years, the TC and EC occurrence levels for each of these systems will be reduced to 50 percent 

of their initial values. After that, the TC and EC occurrence levels return to their initial values. 

Level 2: Following a Level 2 Assessment in a particular year, 5 percent of the systems 

performing the assessment will implement a corrective action that will reduce the TC and EC 

occurrence levels to 0 percent for the remainder of that year and for 1 full year after that. Then, 

for an additional 3 full years, the TC and EC occurrence levels for that system will be reduced to 

25 percent of their initial values. After that, the TC and EC occurrence levels return to their 

initial values. (These alternative Level 2 durations were also applied to the nondisinfecting GWR 

corrective actions.) 

For the more effective corrective actions, the alternative assumptions for Level 1 and 

Level 2 are: 

Level 1: Following a Level 1 Assessment in a particular year, 20 percent of the systems 

performing the assessment will implement corrective actions that will reduce the TC and EC 

occurrence levels to 0 percent for the remainder of that year and for two full years after that. 

Then, for an additional 6 full years, the TC and EC occurrence levels for that system will be 

reduced to 50 percent of their initial values. After that, the TC and EC occurrence levels return to 

their initial values. 

Level 2: Following a Level 2 Assessment in a particular year, 20 percent of the systems 

performing the assessment will implement corrective actions that will reduce the TC and EC 

occurrence levels to 0 percent for the remainder of that year and for 4 full years after that. Then, 

for an additional 10 full years, the TC and EC occurrence levels for that system will be reduced 

to 25 percent of their initial values. After that, the TC and EC occurrence levels return to their 

initial values. (Again, these alternative Level 2 durations were also applied to the nondisinfecting 

GWR corrective actions.) 

A summary of the assumptions used in these alternative sensitivity analyses is provided 

in Exhibit 5.23. The analyses were run in the predictive model for the RTCR for the 

approximately 60,000 nondisinfecting GW TNCWSs serving ≤500 people. This subgroup 

contains the largest number of systems and has on average the largest number of violations of all 

subgroups. This subgroup may experience the largest change in activity under the RTCR 

because, unlike the larger systems that have more resources at their disposal, these systems are 

not generally going beyond requirements of the 1989 TCR, and generally have less frequent 

requirements for sampling under the 1989 TCR than the larger systems. To conduct the 

sensitivity analysis described in this section, EPA applied to the predictive model the alternative 

assumptions that are presented in Exhibit 5.23 along with assumptions applied in the primary 

analysis for comparison. 
Economic Analysis for the Final RTCR 5-48 September 2012 

Exhibit 5.23 Sensitivity Analysis Assumptions for Frequency and Effectiveness of 

Corrective Actions following Level 1 or 2 Assessments 

Type of 

Assessment

% Performing 

Corrective 

Action after a 

Level 1 or Level 

2

1 Assessment

Reduced hit 

rate 

Immediately 

after Corrective 

Action

Period of time 

for reduced hit 

rate2

Additional 

period of 

reduced hit rate 

(yrs)

Reduction from 

initial hit rate in 

additional 

reduced period

Level 1 10% 0% Remainder + 1 3 50%

Level 2 10% 0% Remainder + 2 5 25%

Level 1 5% 0% Remainder only 2 50%

Level 2 5% 0% Remainder + 1 3 25%

Level 1 20% 0% Remainder + 2 6 50%

Level 2 20% 0% Remainder + 4 10 25%

Notes: 

1. Level 2 assumptions for the predictive model and sensitivity analyses are also applied to 100% of nondisinfecting ground water systems 

that incur an EC+ in the source water and implement a nondisinfecting corrective action. 

2. "Remainder" refers to the balance of the year following implementation of a corrective action. 

Predictive Model

Sensitivity 1 - 

Less Effective 

Sensitivity 2 - 

More effective

Exhibit 5.24a Cumulative Effect of Alternative Assumptions for Corrective Action 

(CA) Effectiveness and Duration on RTCR Model Results 

(Nondisinfecting TNCWS Serving ≤500 People over 25 Years) 

RTTC+

RTTC+

as rate RPTC+ RTEC+ RPEC+ GWR EC + Nonacutes Acutes L1 Assmt L2 Assmt L1 CA L2 CA

Low CAs1 300,209 3.81% 204,124 11,585 6,613 3,364 104,161 9,162 68,941 48,658 3,539 2,395

RTCR2 277,776 3.55% 174,200 9,937 5,038 2,906 90,389 7,170 64,275 36,090 6,448 3,671

High CAs3 240,248 3.11% 124,822 8,271 3,942 2,240 67,662 5,352 53,823 20,710 10,664 3,918

50% Option4 229,270 2.97% 110,839 7,887 3,225 2,641 61,424 4,534 53,896 12,506 27,227 6,288

Low CAs1 8.1% 7.42% 17.2% 16.6% 31.2% 15.8% 15.2% 27.8% 7.3% 34.8% -45.1% -34.7%

High CAs3

-13.5% -12.43% -28.3% -16.8% -21.8% -22.9% -25.1% -25.4% -16.3% -42.6% 65.4% 6.7%

50% Option4

-17.5% -16.22% -36.4% -20.6% -36.0% -9.1% -32.0% -36.8% -16.1% -65.3% 322.3% 71.3%

Low CAs1 1.08 1.08 1.17 1.17 1.31 1.16 1.15 1.28 1.07 1.35 0.55 0.65

High CAs3 0.86 0.83 0.72 0.83 0.78 0.77 0.75 0.75 0.84 0.57 1.65 1.07

50% Option4 0.83 0.77 0.64 0.79 0.64 0.91 0.68 0.63 0.84 0.35 4.22 1.71

Notes:

1. "Low CAs" uses half of the primary analysis estimate, or 5% incremental increase in CAs beyond the 1989 TCR (50% decrease in the assumption).

2. "RTCR" refers to the RTCR under assumptions used in the primary analysis, which includes an assumption that 10% more CAs addressing the root cause of a TC/EC 

event will be implemented than under the 1989 TCR (0% change in the assumption).

3. "High CAs" doubles the primary analysis CAs estimate from 10% to 20% (100% increase in the assumption).

4. "50% option" uses a CAs estimate of 50% instead of the primary analysis assumption of 10% (500% increase in the assumption). 

Cumulative effects shown in this exhibit are based on application in the predictive occurrence model of the alternative assumptions for frequency and effectiveness of 

corrective actions following Level 1 or 2 Assessments, as presented in Ex. 5.23. The effectiveness of corrective actions is based both on the effectiveness of the Level 1 or 

Level 2 assessments performed in diagnosing the correct system deficiency(ies) and upon the effectiveness of implementation of the intended corrective action. 

Corrective 

Actions 

Assumption

Model Output

 % Cha nge from RTCR

 Relative Change
Economic Analysis for the Final RTCR 5-49 September 2012 

As expected, the results of these runs indicate that the less frequent and less effective 

corrective action assumptions result in more TC+ and EC+ samples and having more non-acute 

and acute events than the main assumptions. In addition, more L1 and L2 assessments are 

conducted in response to those additional events, but fewer corrective actions are performed. 

Conversely, the more frequent and more effective corrective action assumptions lead to 

fewer TC+, EC+, non-acute, and acute events occurring and more L1 and L2 corrective actions 

being performed. 

The fewer number of TC+, EC+, non-acute and acute events occurring with the more 

effective corrective action assumptions relative to the main assumptions can be viewed as events 

that are prevented from occurring as a result of those more effective actions relative to the main 

assumptions. Similarly, the increased number of those events occurring with the less effective 

corrective actions can be viewed as those that would not be prevented relative to the main 

assumptions. 

It is important to note that this sensitivity analysis is not intended as a rigorous, 

quantitative comparison of the regulatory options, but rather as a general indicator of the 

magnitude and direction of change in these outputs relative to inputs. Broadly speaking, since the 

sensitivity analysis input assumptions reflect changes that are approximately one half and two 

times the main analysis input assumptions, sensitivity analysis outputs that are substantially less 

than half or significantly greater than two times the main analysis outputs could be considered to 

be very sensitive to the changes in the input assumptions. Sensitivity analysis outputs that are 

between one half and twice the main analysis outputs can be considered to be much less sensitive 

to changes in the input assumptions. Note, if the ratio of the outputs from the sensitivity analysis 

to the main analysis is approximately one, it suggests that the outputs of the sensitivity analysis 

are not sensitive to changes in the input assumptions. 

As indicated in Exhibit 5.24b, all of the ratios for outputs fall within the 0.5 to 2.0 range, 

indicating that these outputs do not appear to be highly sensitive to these alternative assumptions 

for corrective action effectiveness. 

The outputs that could serve as indicators of the sensitivity of the benefits to these 

assumptions are the numbers of TC+ and EC+ results predicted as well as the number of nonacute and acute events predicted. These outputs have factors that generally fall well within the 

0.5 to 2.0 range, indicating that these changes in the inputs assumptions appear to result in 

relatively small changes in these outputs. That is, the less effective corrective action assumptions 

do not appear to result in missing a disproportionately greater number of these events, and the 

more effective corrective actions appear to result in finding a disproportionately greater number 

of these events. 

The outputs that could serve as indicators of the sensitivity of the costs on these 

assumptions are the Level 1 and Level 2 assessments and the Level 1 and Level 2 corrective 

actions. The assessments have ratios that, like those for the outputs like TC+ and EC+, are 

generally well within the 0.5 to 2.0 range. The ratios for the corrective actions are also within 

this range but tend to be close to the 0.5 and 2.0 values. The input assumptions used for the 

number of corrective actions done is directly proportional to the number of assessments 
Economic Analysis for the Final RTCR 5-50 September 2012 

performed, so these changes would be expected to be more directly linear (closer to 0.5 or 2.0). 

For example, using the more effective corrective action assumptions, the number of TC+ 

samples predicted is reduced, as are the number of Level 1 assessments that are related to TC+ 

events. The ratio for Level 1 assessments under the more effective corrective action assumptions 

is 0.84, indicating that under these assumptions systems will only need to perform about 85 

percent of the Level 1 assessments over the 25-year period (that is, the others are prevented by 

the more effective actions). However, this set of alternative assumptions includes a factor that 20 

percent of those doing Level 1 assessments go on to do Level 1 corrective actions (which is 

twice the 10 percent assumption in the main model). Therefore, we see that almost twice as many 

of these Level 1 corrective actions are performed as under the main model. More specifically, the 

ratio for Level 1 corrective actions is 1.65 which is approximately two times the 0.84 ratio noted 

for Level 1 assessment predicted. 

An additional analysis was run to test the model's sensitivity to the primary analysis 

assumption that 10 percent more corrective actions addressing the root cause of a TC/EC event 

will be implemented than under the 1989 TCR. The additional sensitivity analysis investigates 

the implications of a much greater rate of corrective action implementation—50 percent rather 

than 10 percent, or a 400 percent increase from the primary analysis assumption. All other 

parameters in this sensitivity test, including the effectiveness and duration of the corrective 

actions, are identical to those of the RTCR primary analysis. 

Exhibit 5.24b Cumulative Effect of 50 percent Assumption for Corrective Action 

Implementation Rate on RTCR Model Results 

(Nondisinfecting TNCWS Serving ≤500 People over 25 Years) 

RTTC+

RTTC+

as rate RPTC+ RTEC+ RPEC+ GWR EC + Nonacutes Acutes L1 Assmt L2 Assmt L1 CA L2 CA

RTCR1 277,776 3.55% 174,200 9,937 5,038 2,906 90,389 7,170 64,275 36,090 6,448 3,671

50% Option2 229,270 2.97% 110,839 7,887 3,225 2,641 61,424 4,534 53,896 12,506 27,227 6,288

50% Option2

-17.5% -16.22% -36.4% -20.6% -36.0% -9.1% -32.0% -36.8% -16.1% -65.3% 322.3% 71.3%

50% Option2 0.83 0.77 0.64 0.79 0.64 0.91 0.68 0.63 0.84 0.35 4.22 1.71

Notes:

1. "RTCR" refers to the RTCR under assumptions used in the primary analysis, which includes an assumption that 10% more CAs addressing the root cause of a TC/EC event will 

be implemented than under the 1989 TCR (0% change in the assumption).

2. "50% option" uses a CAs estimate of 50% instead of the primary analysis assumption of 10% (500% increase in the assumption). 

Corrective 

Actions 

Assumption

Model Output

 % Cha nge from RTCR

 Relative Change

As might be expected, this modification causes rates of Level 1 and Level 2 corrective 

actions to increase. This in turn decreases the RTTC+ rate and other levels of occurrence, 

including the number of Level 1 and Level 2 assessments. It is interesting to note that the rate of 

Level 1 corrective actions increases much more dramatically than the rate of Level 2 corrective 

actions. One possible explanation for this is that with the higher corrective action implementation 

rate, more systems move to a reduced TC occurrence level during the first years of RTCR. 

Thereafter these systems are more likely to trigger Level 1 assessments than Level 2 

assessments, causing the ratio of Level 1 corrective actions to Level 2 corrective actions to shift 

substantially from that predicted in the primary analysis. 

Since this analysis involves changing a parameter by a factor of five, changes in model 

output greater than a factor of five would indicate a high degree of sensitivity to the parameter. 
Economic Analysis for the Final RTCR 5-51 September 2012 

In the table it is evident that no changes on that scale occur. Nonetheless, the analysis does 

indicate that an increase in the rate of implementation of corrective actions would reduce the 

long-run incidence of TC/EC events and that it would increase the number of Level 1 corrective 

actions more dramatically than it would increase the number of Level 2 corrective actions.

Additional Factors Assessed 

As described in the introduction to this section, there were assumptions in addition to the 

frequency and effectiveness of corrective actions that EPA considered might influence the 

analysis. These assumptions were categorized as those that were unlikely to have an impact on 

net results (5.22a), and those that affected the RTCR and Alternative option differently than the 

1989 TCR (5.22b), thus having the potential to impact net results. 

Because the effect of seasonality on occurrence is commonly a concern when using 

annual average occurrence rates in an analysis, and because RTTC occurrence rates were found 

to be twice as high in the summer and fall as in the winter and spring, EPA ran a sensitivity 

analysis on the influence of seasonal trends. This analysis was performed on the subset including 

transient nondisinfecting ground water systems serving fewer than 101 people because of its 

relatively large number of systems and high occurrence rate. For simplicity, the sensitivity 

analysis was limited to only the RTCR. 

EPA performed the sensitivity analysis through two runs of the RTCR model. The first 

run established a baseline, and the second multiplied the assigned baseline pRTTC values by a 

factor of 0.67 during December–May and by a factor of 1.33 during June–November. (No 

seasonality factors were applied for systems on annual sampling.) 

Summary results in Table 5.25 show expected yearly averages for selected occurrence 

metrics during the first 25 years under full implementation of the RTCR. Overall the differences 

between the model results are small. Also, they are not consistently higher for one model (e.g., 

when accounting for seasonality, total TC occurrence is slightly lower but the number of acutes 

is slightly higher). These variations are likely within the range of Monte Carlo error. Therefore, 

EPA determined that not incorporating seasonality into the occurrence model is an acceptable 

simplification. 

Exhibit 5.25 Effect of Seasonality on Occurrence Analysis Endpoints 

RTCR Metric No Seasonality Seasonality

Total TC Positives 8,560 8,556

Total Level 1 Triggers 2,824 2,784

Total Acutes1 225 240

L1 Corrective Actions 201 194

L2 Corrective Actions 113 104

Notes: 

Estimates represent a yearly average during the first 25 years 

under full implementation of the RTCR.

1. Includes those Level 2 Triggers resulting from an EC+ 

(does not include those resulting from a second Level 1 

trigger occurring within a 12-month rolling period).
Economic Analysis for the Final RTCR 5-52 September 2012 

5.3.3.2 Model Validation 

There are a limited number of ways in which outputs from the predictive model for the 

systems serving ≤4,100 people can be compared to observed data. EPA has identified two types 

of analyses where comparisons can be made. One of these is to compare the model’s predictions 

of average annual TC and EC occurrence levels for various types and sizes of systems under the 

1989 TCR against the observations from the 2005 Six-Year Review data used to parameterize 

the model. The other is to compare the model’s predictions for the 1989 TCR against those 

reported in SDWIS/FED. 

It is necessary to keep in mind that the primary purpose of the modeling effort for the 

systems serving ≤4,100 people was not to exactly match observed results but to provide a 

framework for comparing relative changes across regulatory options. Nevertheless, it is 

important that, to the extent possible, the model outputs for conditions that can be checked 

against observed data compare reasonably well. This provides assurance that the model is 

operating in a manner that is a reasonable simulation of how the 1989 TCR currently operates 

and provides some measure of confidence that the relative changes seen for the regulatory 

options are meaningful. 

Exhibit 5.26 provides a comparison of the model results for average annual TC+ assays 

under the 1989 TCR with those observed in the 2005 Six-Year Review data. 
Economic Analysis for the Final RTCR 5-53 September 2012 

Exhibit 5.26 Comparison of TC+ Occurrence Predicted as a 25-Year Annual 

Average under the 1989 TCR with 2005 Six-Year Review Data 

TC

(% Positive)

EC

(% Positive)

TC

(% Positive)

EC

(% Positive)

≤100 1.41% 0.09% 1.43% 0.18%

101-500 1.15% 0.05% 0.92% 0.12%

501-1,000 0.70% 0.05% 0.95% 0.13%

1,001-4,100 0.57% 0.03% 0.57% 0.04%

≤100 2.66% 0.08% 2.23% 0.10%

101-500 1.99% 0.05% 1.69% 0.08%

501-1,000 1.52% 0.04% 1.49% 0.07%

1,001-4,100 1.07% 0.02% 0.99% 0.05%

≤100 1.92% 0.24% 1.43% 0.18%

101-500 0.39% 0.09% 1.08% 0.14%

501-1,000 0.64% 0.00% 1.06% 0.14%

1,001-4,100 0.08% 0.00% 1.03% 0.12%

≤100 3.17% 0.07% 2.91% 0.14%

101-500 2.70% 0.06% 2.00% 0.10%

501-1,000 1.74% 0.02% 1.86% 0.11%

1,001-4,100 1.35% 0.04% 1.49% 0.09%

Transient, Noncommunity Water Systems (TNCWSs) - SW

≤100 2.23% 0.25% 2.15% 0.27%

101-500 2.63% 0.46% 2.18% 0.29%

501-1,000 3.63% 0.00% 2.17% 0.29%

1,001-4,100 0.61% 0.00% 2.04% 0.27%

Transient, Noncommunity Water Systems (TNCWSs) - GW

≤100 4.78% 0.20% 4.17% 0.19%

101-500 4.57% 0.19% 4.04% 0.20%

501-1,000 4.30% 0.06% 3.86% 0.20%

1,001-4,100 2.02% 0.03% 2.09% 0.12%

Source: Derived using 2005 Six-Year Review 2 Data. 1989 TCR data from model output.

Community Water Systems (CWSs) - GW

Community Water Systems (CWSs) - SW

Nontransient, Noncommunity Water Systems (NTNCWSs) - SW

Nontransient, Noncommunity Water Systems (NTNCWSs) - GW

Six Year review Predictive Model

Population

Served

The comparison of the predictive model output with the Six-Year data for TC and EC 

occurrence levels (based on number of TC routine samples taken) shows a reasonable 

concordance for all types and sizes of systems. With respect to the differences, the model does 

not appear to be either systematically overestimating or underestimating the occurrence levels 

compared with the Six-Year Review data (except where the Six-Year Review data show 0 

percent observed, the model does show a low level of occurrence). 

Exhibit 5.27 provides a comparison of the model results of the average annual non-acute 

and acute violations for the 1989 TCR with the same metric from SDWIS data for 2005 3rd
Economic Analysis for the Final RTCR 5-54 September 2012 

quarter. (Violations data are downloaded from SDWIS on an annual basis in 3rd quarter only, and 

are not disaggregated by month.) 

Exhibit 5.27 Comparison of SDWIS Data for Non-acute and Acute Violations with 

Predictive Model Annual Results for the 1989 TCR 

SDWIS

Predictive 

Model SDWIS

Predictive 

Model SDWIS

Predictive 

Model SDWIS

Predictive 

Model

CWSs

≤100 905 955 16 31 52 97 3 7

101-500 809 733 50 34 34 81 7 8

501-1,000 203 191 16 19 13 19 3 5

1,001-4,100 338 347 83 49 12 35 6 7

Total 2,255 2,226 165 133 111 231 19 27

NTNCWSs

≤100 514 560 7 7 34 60 2 2

101-500 346 265 4 6 20 - 30 1

501-1,000 57 61 2 2 6 7 - 0

1,001-4,100 62 98 1 3 6 - 12 1

Total 979 985 14 18 66 109 2 4

TNCWSs

≤100 2,665 4,109 19 81 278 445 5 19

101-500 1,371 833 11 31 76 156 1 8

501-1,000 133 144 4 5 11 - 16 1

1,001-4,100 58 105 2 9 2 - 13 2

Total 3,689 5,730 36 126 367 630 6 31

Grand Total 6,923 8,940 215 277 544 970 27 61

Source: SDWIS 2005 Q3 download and occurrence and predictive model results.

Note: Predictive Model reflects annual average results for model years 16 to 40 without inclusion of the GWR.

System 

Size

Non-Acute Violations Acute Violations

GW S W GW S W

The comparison of the predictive model output with the SDWIS violations data also 

shows a reasonable concordance for all types and sizes of systems. EPA believes there is some 

under-counting of actual violations in SDWIS due to monitoring and reporting violations, which 

the model does not incorporate. Therefore, EPA generally expects that the model would generate 

results that are higher than the observed SDWIS data. While a comparison reveals that some of 

the model estimates are lower than the SDWIS statistics, the grand totals for the model are 

consistently higher than those observed in SDWIS. 

5.4 Occurrence Analysis for Systems Serving More Than 4,100 People 

Systems serving populations greater than 4,100 are similar in many ways. In particular, 

these systems generally have the resources and are managed in ways that lead to generally high 

expectations for the integrity of the distribution systems and the ability of the systems to identify 

and correct problems. Some of these similarities may include: 
Economic Analysis for the Final RTCR 5-55 September 2012 

 Most of these systems operate with certified operators, are staffed at all operating 

times, and usually operate continuously. 

 Most of these systems have operators for whom producing water is their primary 

activity, and most are owned by communities rather than run as ancillary 

businesses. 

 As a result of the professional operations, these systems have a much lower 

incidence of monitoring and reporting violations. 

 Many of these systems have their own laboratory for analyzing samples. 

 Many more of these systems disinfect their water. 

 These systems take at least five samples per month. The largest of these systems 

take hundreds of samples per month. There is no requirement for “additional next 

month samples” as there is for systems serving ≤4,100 people because systems 

serving >4,100 people already take at least five samples each month. 

 The monitoring frequency changes under the RTCR mostly do not affect systems 

serving more than 4,100 people; all systems take at least five samples per month. 

For systems serving more than 4,100 people, EPA assumes that occurrence may change 

based on the extra distribution system awareness created by: a) applying the Level 1 and Level 2 

assessments in lieu of prior assessments that may, in some cases, have been less structured; and 

b) reporting the assessment results. Therefore, EPA developed a simple model to predict the 

effects of the RTCR and Alternative option on PWSs and to compare those data to the baseline 

data predicted for the 1989 TCR. EPA did not quantify changes in violation or trigger rates for 

systems serving more than 4,100 people among the 1989 TCR, the RTCR, and Alternative 

option because of: (1) limited Six-Year Review data to characterize these systems; (2) the 

essentially unchanged monitoring requirements across options for these systems; and (3) the 

level of effort already occurring to implement the 1989 TCR. 

5.4.1 Model (for Systems Serving >4,100 People) 

As input for this model, EPA first considered 2005 data for the 1989 TCR on sampling 

and positive assays that were compiled under the Six-Year Review, as was incorporated into the 

model for systems serving ≤4,100 people. However, as discussed in Section 4.2.2.3, detailed 

sampling results from the Six Year Review data were not representative of the universe of 

systems serving >4,100 people. EPA instead found that violations data were adequately 

representative of the universe of systems serving >4,100 people. This input to the model, based 

on 2005 SDWIS data (see Exhibit 4.10), was used to predict violations that systems serving more 

than 4,100 people will incur in the 25-year period of RTCR analysis, and the behavioral 

responses (Level 1 and Level 2 assessments and corrective actions) that would result. 

The model uses the same stratification as the model for systems serving ≤4,100 people—

by system type (CWS, TNCWS, or NTNCWS) and by water source (SW or GW). For each 

system in a given category the model applies the 2005 SDWIS violations rate for that category. 
Economic Analysis for the Final RTCR 5-56 September 2012 

This rate is applied in each year of the analysis, that is, the violations rate is a constant in the 

model. For estimating the effects on violations under the RTCR and Alternative option, the 

model estimates that 10 percent of the assessments resulting from violations will result in 

corrective actions, the same value applied in the analysis of the systems serving ≤4,100 people. 

This 10 percent represents the net increase in efficacy of addressing the root cause of system 

contamination under the RTCR and Alternative option compared to the 1989 TCR. 

Repeat samples are reduced in the model under the RTCR and Alternative option from 

the 1989 TCR. They are calculated by applying the ratios of repeat samples to routine samples 

from systems serving 1,001–4,100 people to the systems serving more than 4,100 people. 

The model output, shown in Section 5.4.2, includes predictions of the annual number of 

violations (non-acute = Level 1, acute = Level 2), and the number of Level 1 and Level 2 

assessments and corrective actions to be implemented. 

5.4.2 Model Results (for Systems Serving >4,100 People) 

Exhibits 5.28 through 5.30 present model results for systems serving more than 4,100 

people by size category. 

5.4.3 Model Uncertainty (for Systems Serving >4,100 People) 

As explained in Section 5.4.1 of this chapter, EPA does not expect systems serving 

>4,100 people to experience changes in routine monitoring or repeat sample regimes under the 

regulatory options; furthermore, all systems in this size range are on monthly sampling. 

Therefore, the model for systems serving >4,100 people was relatively simple compared to that 

for the systems serving ≤4,100 people, and EPA did not develop an uncertainty analysis for this 

group of systems. 
Economic Analysis for the Final RTCR 5-57 September 2012 

Exhibit 5.28 Results for Systems Serving more than 4,100 People—1989 TCR 

A B C D E F G H I

Community Water Systems (CWSs) - SW

4,101-33,000 10,636,296 - 186,729 - 2,152 - 197 - -

33,001-96,000 11,058,960 - 194,149 - 534 - 56 - -

96,001-500,000 10,190,400 - 178,901 - 233 - 24 - -

500,001-1 Million 2,019,600 - 35,456 - 22 - - - -

> 1 Million 1,686,960 - 29,616 - - - - - -

Community Water Systems (CWSs) - GW

4,101-33,000 9,145,224 - 230,201 - 4,545 - 263 - -

33,001-96,000 4,884,000 - 122,938 - 656 - 53 - -

96,001-500,000 1,945,680 - 48,976 - 129 - 10 - -

500,001-1 Million 253,440 - 6,380 - - - - - -

> 1 Million 269,280 - 6,778 - - - - - -

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

4,101-33,000 50,424 - 1,628 - 5 - - - -

33,001-96,000 34,320 - 1,108 - - - - - -

96,001-500,000 31,680 - 1,023 - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million - - - - - - - - -

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

4,101-33,000 153,648 - 5,936 - 123 - 9 - -

33,001-96,000 23,760 - 918 - 4 - - - -

96,001-500,000 - - - - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million - - - - - - - - -

Transient Noncommunity Water Systems (TNCWSs) - SW

4,101-33,000 40,656 - - - 8 - - - -

33,001-96,000 - - - - - - - - -

96,001-500,000 - - - - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million 102,960 - - - - - - - -

Transient Noncommunity Water Systems (TNCWSs) - GW

4,101-33,000 156,288 - 8,909 - 116 - 4 - -

33,001-96,000 34,320 - 1,956 - - - - - -

96,001-500,000 26,400 - 1,505 - - - - - -

500,001-1 Million 63,360 - 3,612 - - - - - -

> 1 Million - - - - - - - - -

Source: Appendix A, Exhibit A.1.z.

Note: For modeling purposes, EPA estimated only the net change i n the number o f corrective actions performed under the RTCR and Alternative option

compared to the 1989 TCR. Because only the net change i n the number o f corrective actions i s estimated, n o additional corrective actions are modeled for the

1989 TCR (it is assumed that PWSs are already performing some corrective actions under the 1989 TCR).

Number of 

Corrective 

Actions

(based on 

Single NonAcute 

Violation 

Assessment)

Number of 

Non-Acute 

Violation 

Assessments 

(Single 

Violations)

Number of 

Non-Acute 

Violation 

Assessments

(Multiple 

Violations)

Number of 

Corrective 

Actions

(based on 

Acute and 

Multiple NonAcute Violation 

Assessments)

Number of 

Acute 

Violation 

Assessments

PWSs 

Performing 

Additional 

Annual Site 

Inspections

PWS Size

(Population

Served)

Number of 

Routine 

Monitoring 

Samples

Number of 

Additional 

Routine 

Monitoring 

Samples

Number of 

Repeat 

Monitoring 

Samples
Economic Analysis for the Final RTCR 5-58 September 2012 

Exhibit 5.29 Results for Systems Serving more than 4,100 People—RTCR 

A B C D E F G H I

Community Water Systems (CWSs) - SW

4,101-33,000 10,636,296 - 181,661 - 2,152 215 197 - 20

33,001-96,000 11,058,960 - 188,880 - 534 53 56 - 6

96,001-500,000 10,190,400 - 174,046 - 233 23 24 - 2

500,001-1 Million 2,019,600 - 34,493 - 22 2 - - -

> 1 Million 1,686,960 - 28,812 - - - - - -

Community Water Systems (CWSs) - GW

4,101-33,000 9,145,224 - 217,321 - 4,545 454 263 - 26

33,001-96,000 4,884,000 - 116,060 - 656 66 53 - 5

96,001-500,000 1,945,680 - 46,236 - 129 13 10 - 1

500,001-1 Million 253,440 - 6,023 - - - - - -

> 1 Million 269,280 - 6,399 - - - - - -

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

4,101-33,000 50,424 - 1,448 - 5 0 - - -

33,001-96,000 34,320 - 985 - - - - - -

96,001-500,000 31,680 - 910 - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million - - - - - - - - -

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

4,101-33,000 153,648 - 5,157 - 123 12 9 - 1

33,001-96,000 23,760 - 797 - 4 0 - - -

96,001-500,000 - - - - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million - - - - - - - - -

Transient Noncommunity Water Systems (TNCWSs) - SW

4,101-33,000 40,656 - 2,225 - 8 1 - - -

33,001-96,000 - - - - - - - - -

96,001-500,000 - - - - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million 102,960 - 5,636 - - - - - -

Transient Noncommunity Water Systems (TNCWSs) - GW

4,101-33,000 156,288 - 7,188 - 116 12 4 - 0

33,001-96,000 34,320 - 1,578 - - - - - -

96,001-500,000 26,400 - 1,214 - - - - - -

500,001-1 Million 63,360 - 2,914 - - - - - -

> 1 Million - - - - - - - - -

Number of 

Corrective 

Actions (based 

on Level 1 

Assessments)

Number of 

Routine 

Monitoring 

Samples

Number of 

Additional 

Routine 

Monitoring 

Samples

Source: Appendix A, Exhibit A.2.z.

Note: Estimates o f the number o f assessments and corrective actions are net increases i n activity predicted to occur under the RTCR relative to the 1989 TCR;

estimates of zero reflect that no additional such activity occurs as compared to baseline (the 1989 TCR). 

Number of 

Level 2 

Assessments 

(based on 

Acute 

Violations)

Number of 

Repeat 

Monitoring 

Samples

PWSs 

Performing 

Additional 

Annual Site 

Inspections

Number of 

Level 1 

Assessments

Number of 

Level 2 

Assessments 

(based on NonAcute 

Violations)

PWS Size

(Population

Served)

Number of 

Corrective 

Actions (based 

on Level 2 

Assessments)
Economic Analysis for the Final RTCR 5-59 September 2012 

Exhibit 5.30 Results for Systems Serving more than 4,100 People—Alternative 

Option 

A B C D E F G H I

Community Water Systems (CWSs) - SW

4,101-33,000 10,636,296 - 181,661 - 2,152 215 197 - 20

33,001-96,000 11,058,960 - 188,880 - 534 53 56 - 6

96,001-500,000 10,190,400 - 174,046 - 233 23 24 - 2

500,001-1 Million 2,019,600 - 34,493 - 22 2 - - -

> 1 Million 1,686,960 - 28,812 - - - - - -

Community Water Systems (CWSs) - GW

4,101-33,000 9,145,224 - 217,321 - 4,545 454 263 - 26

33,001-96,000 4,884,000 - 116,060 - 656 66 53 - 5

96,001-500,000 1,945,680 - 46,236 - 129 13 10 - 1

500,001-1 Million 253,440 - 6,023 - - - - - -

> 1 Million 269,280 - 6,399 - - - - - -

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

4,101-33,000 50,424 - 1,448 - 5 0 - - -

33,001-96,000 34,320 - 985 - - - - - -

96,001-500,000 31,680 - 910 - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million - - - - - - - - -

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

4,101-33,000 153,648 - 5,157 - 123 12 9 - 1

33,001-96,000 23,760 - 797 - 4 0 - - -

96,001-500,000 - - - - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million - - - - - - - - -

Transient Noncommunity Water Systems (TNCWSs) - SW

4,101-33,000 40,656 - 2,225 - 8 1 - - -

33,001-96,000 - - - - - - - - -

96,001-500,000 - - - - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million 102,960 - 5,636 - - - - - -

Transient Noncommunity Water Systems (TNCWSs) - GW

4,101-33,000 156,288 - 7,188 - 116 12 4 - 0

33,001-96,000 34,320 - 1,578 - - - - - -

96,001-500,000 26,400 - 1,214 - - - - - -

500,001-1 Million 63,360 - 2,914 - - - - - -

> 1 Million - - - - - - - - -

Number of 

Corrective 

Actions (based 

on Level 2 

Assessments)

PWSs 

Performing 

Additional 

Annual Site 

Inspections

Source: Appendix A, Exhibit A.3.z.

Note: Estimates of the number of assessments and corrective actions are net increases in activity predicted to occur under the Alternative option relative to the 

1989 TCR; estimates of zero reflect that no additional such activity occurs as compared to baseline (the 1989 TCR). 

Number of 

Level 1 

Assessments

Number of 

Corrective 

Actions (based 

on Level 1 

Assessments)

Number of 

Level 2 

Assessments 

(based on 

Acute 

Violations)

Number of 

Level 2 

Assessments 

(based on NonAcute 

Violations)

PWS Size

(Population

Served)

Number of 

Routine 

Monitoring 

Samples

Number of 

Additional 

Routine 

Monitoring 

Samples

Number of 

Repeat 

Monitoring 

Samples

5.5 Summary of Key Drivers for Benefit and Cost Analyses Output from the Predictive 

Model 

As presented in Exhibits 5.10–5.15, the model for systems serving ≤4,100 people 

produces estimates of the number of samples, the number of Level 1 and Level 2 assessments, 

and the number of corrective actions implemented as a result of Level 1 and Level 2 assessments 

under each regulatory option. For the RTCR and Alternative option, the model calculates the 

corrective actions performed as a net increase from those performed under the 1989 TCR. Those 

corrective actions performed under the 1989 TCR are described in Chapter 7 in the discussion of 

1989 TCR costs. The net change in each of the model outputs, in particular sampling regimens 

and implementation of assessments and corrective actions relative to the 1989 TCR and under 

the RTCR and Alternative option provides the basis for estimating the benefits in the rule, 
Economic Analysis for the Final RTCR 5-60 September 2012 

described in Chapter 6 of this EA. Similarly, the cost model applies unit costs to the activities 

described by these outputs to produce net costs for each regulatory option considered, as 

described in Chapter 7. 

As described in the uncertainty discussion and sensitivity analysis presented in Section 

5.3.3.1, these key drivers represent the most significant source of uncertainty in the analysis. 

However, the sensitivity analysis showed that a doubling in the implementation and effectiveness 

assumptions for corrective actions (the proportional increase in the number of effective 

corrective actions implemented and the duration and extent of reduced occurrence) implemented 

under the RTCR would result in only approximately a 25 percent decrease in acute events. 

Conversely, a 50 percent reduction in corrective action implementation and effectiveness was 

estimated to induce less than a 28 percent increase in acute events. These results are expected to 

apply similarly to all categories of systems. Based on these results, EPA concludes that changing 

the assumptions within the likely range (a doubling or halving of current assumptions) would not 

have a significant effect on the conclusions drawn from this EA. Similarly, varying the 

assumptions by size and type of system within a likely range would not be expected to have a 

significant effect on the results. 

For systems serving >4,100 people, the net change in costs is estimated for the additional 

reporting requirements under the rule, as well as the additional corrective actions implemented 

for these systems. However, as described in Section 5.4, the sampling regimens are not expected 

to change for these systems, and they likely would experience minimal changes in risk and cost, 

as described in Chapter 6 and Chapter 7 of this EA, respectively.
Economic Analysis for the Final RTCR 6-1 September 2012 

6 Benefits Analysis 

6.1 Introduction 

This chapter considers the overall change in risk of contamination to public water 

systems (PWSs), as indicated by the presence of total coliforms (TC) and E. coli, associated with 

compliance with the 1989 Total Coliform Rule (1989 TCR) and with the Revised Total Coliform 

Rule (RTCR) and the Alternative option. Since E. coli is an indicator of fecal contamination 

(Edberg et al., 2000), EPA assumes that a decrease in E. coli occurrence in the distribution 

system would be associated with a decrease in fecal contamination in the distribution system. In 

general, this decrease in fecal contamination should reduce the potential risk to human health for 

PWS customers. Thus, any reduction in E. coli occurrence is considered a benefit of the RTCR. 

Since fecal contamination may contain waterborne pathogens including bacteria, viruses, and 

parasitic protozoa, in general, a reduction in fecal contamination should reduce the risk from all 

of these contaminants. 

Based on limitations in available data as described further in Section 6.4 of this chapter, 

EPA determined that benefits could not be calculated in terms of avoided costs or other 

quantified benefits related to avoided morbidity or mortality. Therefore, this economic analysis 

(EA) focuses on a qualitative analysis of risk, which is supported by quantitative analysis of 

predicted outcomes for each regulatory option. The quantitative discussion focuses on net 

changes in occurrence of contaminant indicators under both regulatory options (RTCR and 

Alternative option) considered as compared to the 1989 TCR option. The qualitative analysis 

considers the direction of anticipated changes in risk related to changes in sampling and 

corrective action regimens under each regulatory option (Section 6.2). EPA considered the 

results of the qualitative and quantified assessments to determine how the 1989 TCR compares to 

the RTCR and Alternative option in terms of overall change in risk to the population served by 

PWSs across the United States. The remainder of this chapter is organized into four sections, as 

follows: 

 Section 6.2 presents qualitative benefits analyses. 

 Section 6.3 presents an assessment of the predictive analysis results. 

 Section 6.4 presents uncertainty and sensitivity analyses. 

 Section 6.5 discusses other potential benefits. 

6.2 Qualitative Benefits Analyses 

When revising an existing drinking water regulation, one of the main concerns is to 

ensure that backsliding on water quality and public health protection does not occur. The Safe 

Drinking Water Act (SDWA) states that any revision to a regulation must “maintain, or provide 

for greater protection for the health of persons.” Risk reduction for the RTCR is characterized by 

the activities performed that are presumed to reduce risk of exposing the public to contaminated 

water. These activities are considered under each rule component discussed in Sections 6.2.1–

6.2.8 and summarized in Figure 6.1 below. The discussion in Section 6.2.9 considers how 
Economic Analysis for the Final RTCR 6-2 September 2012 

expected overall increases in the risk for some rule components are offset by expected overall 

decreases resulting from other components, and provides a net assessment of the direction in 

change of risk for the regulatory options considered. 

The qualitative analysis uses the best professional judgment of EPA as informed by Total 

Coliform Rule Distribution System Advisory Committee (TCRDSAC) deliberations,38 as well as 

certain quantitative estimates, to predict the directional change in risk for each rule component of 

the RTCR and the Alternative option. Quantitative estimates considered include the changes in 

TC occurrence and counts of systems conducting assessments and implementing corrective 

actions shown in Exhibits 6.2–6.6. Exhibit 6.1 presents a summary of this evaluation for the 

RTCR and Alternative option as compared to the 1989 TCR. The qualitative analysis discusses 

the influence of the individual rule components under each regulatory option considered on the 

occurrence of TC-positive (TC+) and E. coli-positive (EC+) samples. Since a dose-response 

relationship between exposure to the fecal indicator E. coli and adverse health effects from 

waterborne pathogens that can be present with fecal contamination is not available, the resulting 

risk to human health is discussed only in terms of the anticipated change in direction of risk. 

6.2.1 Implementation Activities 

Rule implementation activities are expected to be similar under the RTCR and 

Alternative option. These activities are primarily administrative in nature and include items such 

as reading and understanding the rule, training, and development of reporting and recordkeeping 

protocols. Because of the similarities in expected implementation activities under the regulatory 

options, they are not expected to have an observably different effect on overall risk relative to the 

1989 TCR. Both PWSs and states would incur additional burden and costs for transitioning to 

operations under the RTCR or Alternative option requirements. Because the activities undertaken 

to make the transition are primarily administrative, the additional activities are not expected to 

have any direct impact on risk. 

6.2.2 Routine Monitoring 

EPA expects that more frequent monitoring would decrease the risk of contamination in 

PWSs based on an enhanced ability to diagnose and mitigate system issues in a more timely 

fashion. Conversely, EPA assumes that a less frequent monitoring schedule would result in 

increased risk. Real-time continuous sampling would mitigate the most risk possible based on 

sampling schedule; however, it would cost prohibitively more than the periodic sampling 

practiced under the 1989 TCR and included in the RTCR and the Alternative option. EPA’s 

objective in proposing the sampling schedules included in the RTCR and Alternative option was 

to find an appropriate balance between the factors of risk mitigation and cost management. 

1989 TCR 

The 1989 TCR requires a large portion (approximately 40 percent) of water systems to 

perform monthly monitoring for TC. The remaining systems are eligible for reduced monitoring, 

as follows. 

 

38 TCRDSAC deliberations are described in Chapter 3 of this EA. 
Economic Analysis for the Final RTCR 6-3 September 2012 

 GW noncommunity water systems (GW NCWSs) serving ≤1,000 people are 

required to monitor quarterly. States may allow annual monitoring if a sanitary 

survey conducted in the past 5 years shows the system is supplied solely by 

protected GW sources and is free of sanitary defects. 

 GW community water systems (GW CWSs) serving ≤1,000 people may monitor 

quarterly if they have no history of TC contamination in their current 

configurations, and if a sanitary survey conducted in the past 5 years shows that the 

system is supplied solely by a protected GW source and has no sanitary defects. 

RTCR 

The eligibility requirements for GW systems to qualify for reduced monitoring under the 

RTCR are more stringent than under the 1989 TCR, leading to fewer PWSs qualifying for 

reduced monitoring and therefore a higher total number of routine samples being taken over the 

25-year period of analysis. The primacy agency has the discretion to reduce monitoring 

frequency for well-operated GW NCWSs and GW CWSs serving ≤1,000 people. Under the 

RTCR, eligibility for reduced monitoring for NCWSs and CWSs, respectively, is provided only 

for the following types of PWSs, as discussed as follows. 

NCWSs 

To be eligible to qualify for and remain on annual monitoring after the compliance 

effective date, GW NCWSs serving ≤1,000 people must meet each of the following criteria:

 The most recent sanitary survey shows the system is free of sanitary defects and has 

a protected water source and meets approved construction standards; 

 The system must have a clean (1989 TCR or RTCR) compliance history (no MCL 

violations, Level 1 triggers, Level 2 triggers, treatment technique violations or 

monitoring violations) for a minimum of 12 months; 

 An annual site visit (recurring) by the primacy agency within the last 12 months and 

correction of all identified sanitary defects. A voluntary Level 2 assessment by a 

party approved by the primacy agency may be substituted for the primacy agency 

annual site visit; and 

 The primacy agency should encourage additional enhancements to the barriers 

protecting the distribution system from contamination. These measures could 

include but are not limited to the following: 

– Cross connection control, as approved by the primacy agency; 

– An operator certified by an appropriate primacy agency certification 

program; regular visits by a circuit rider may substitute for this 

requirement for some PWS types as permitted by the state; 
Economic Analysis for the Final RTCR 6-4 September 2012 

– Continuous disinfection entering the distribution system and a residual in 

the distribution system in accordance with criteria specified by the 

primacy agency; and 

– Maintenance of at least a 4-log inactivation of viruses each day of the 

month based on daily monitoring as specified in the Ground Water Rule 

(GWR) (with allowance for a 4-hour exception). 

– Other equivalent enhancements to water system barriers as approved by 

the primacy agency. 

CWSs 

To be eligible to change from monthly to quarterly reduced monitoring after the 

compliance date, GW CWSs serving ≤1,000 people must be in compliance with any statecertified operator provisions and meet each of the following criteria: 

 The most recent sanitary survey shows the system is free of sanitary defects (or has 

an approved plan and schedule to correct them), has a protected water source, and 

meets approved construction standards; 

 The system must have a clean (1989 TCR or RTCR) compliance history (no MCL 

violations, Level 1 or Level 2 triggers, treatment technique violations or monitoring 

violations) for a minimum of 12 months; and 

 Meet at least one of the following criteria: 

– An annual site visit by the primacy agency or a voluntary Level 2 

assessment by a party approved by the primacy agency and correction of 

all identified sanitary defects (or an approved plan and schedule to correct 

them); or 

– A cross connection control program, as approved by the primacy agency; 

or

– Continuous disinfection entering the distribution system and a residual in 

the distribution system in accordance with criteria specified by the 

primacy agency; or 

– At least 4-log inactivation of viruses each day of the month based on daily 

monitoring as specified in the GWR (with allowance for a 4-hour 

exception); or 

– Other equivalent enhancements to water systems as approved by the 

primacy agency. 

Based on the additional protection provided by the more stringent criteria to qualify for 

reduced monitoring, the RTCR is expected to reduce risk for GW systems that qualify for 
Economic Analysis for the Final RTCR 6-5 September 2012 

reduced monitoring compared to the eligibility requirements under the 1989 TCR. In addition, 

those systems that no longer qualify for reduced monitoring are expected to have a reduced risk 

as a function of the increased numbers of samples taken. 

Seasonal systems (NCWSs that are not operated as a PWS on a year-round basis and start 

up and shut down the system at the beginning and end of each operating season) that sample on a 

reduced schedule under the 1989 TCR may retain their current schedules unless a state 

determines that more frequent sampling is appropriate. For seasonal systems required to move to 

an increased monitoring schedule, risk would decrease as a function of the increase in 

monitoring. In addition, more explicit procedural requirements related to monitoring under the 

RTCR (i.e., samples must be taken during the period of highest vulnerability or peak usage) 

would also be expected to reduce risk for seasonal systems. 

Alternative option 

Under the Alternative option, all systems must initially collect TC samples monthly 

regardless of size or type (i.e., water source), which is more frequent for those systems on 

reduced monitoring schedules under the 1989 TCR or RTCR. Over time, in the second year of 

rule implementation and beyond, the Alternative option would allow some GW systems to 

reduce to quarterly monitoring if the systems meet the same qualifications required for quarterly 

monitoring under the RTCR. Reduced monitoring on an annual schedule is not allowed under the 

Alternative option, creating a further increase in samples taken over the 1989 TCR and RTCR. 

Overall, the more frequent monitoring requirements (i.e., all PWSs monitor monthly in the first 

few years after promulgation and no annual reduced monitoring is allowed) would reduce risk as 

compared to the 1989 TCR to a greater extent than under the RTCR. 

6.2.3 Repeat Monitoring 

Under the 1989 TCR, PWSs serving ≤1,000 people take four repeat samples at and within 

five service connections upstream and downstream of the initial TC+ occurrence event over the 

course of 24 hours following the event. Three repeat samples are required for PWSs serving 

>1,000 people, including one sample at the site of the initial TC+ and two additional samples 

within five service connections up or downstream of that site. 

Under the RTCR and Alternative option, PWSs serving ≤1,000 people are only required 

to take three repeat samples. The reduction in the number of repeat samples required could 

increase risk for any individual sampling event. However, the effect of the reduced sampling is 

expected to be minor. Analysis of the data (see Appendix H for the complete analysis) shows 

that for all PWSs serving 1,000 people or fewer, two or more of the repeat samples are positive 

in 75 percent of those instances in which there are any positive repeat samples. For those 75 

percent of instances, reducing the number of repeat samples from four to three would have no 

effect on the number of systems that would be triggered to conduct an assessment of the system 

under the RTCR. In these cases, at least one of the remaining repeat samples would still be TC+, 

and only one positive repeat sample is required to trigger an assessment at these PWSs. 

For 25 percent of the cases in which repeat samples are TC+ under the 1989 TCR, only 

one sample will be positive. EPA estimates that if the number of repeat samples were reduced 
Economic Analysis for the Final RTCR 6-6 September 2012 

from four to three, any positive samples occurring at three of the four original locations (75 

percent) would still be detected. Thus, if the number of required repeat samples were reduced 

from four to three, the number of situations triggering an assessment for the system would be 94 

percent (0.75 + (0.75*0.25) = 0.94) of the number of assessments triggered by taking four repeat 

samples. 

Although dropping the required number of repeat samples from four to three means that 

some fraction of triggered assessments may be missed, representing an increase in risk, EPA 

believes that the other provisions of the RTCR as described in this chapter compensate for that 

change and that, taken as a whole, the provisions of the RTCR provide for greater protection of 

public health. 

6.2.4 Additional Routine Monitoring 

Under the 1989 TCR, PWSs serving ≤4,100 people must conduct additional routine 

monitoring in the month following a TC+ sample. All systems must collect and test a minimum 

of five samples in the month following the TC+ sample, unless the primacy agency finds that 

additional sampling is unnecessary or the primacy agency determines the cause of the TC+ 

sample and establishes that the system has corrected or would correct the problem. 

Under the RTCR, EPA will retain the requirement of taking additional routine samples 

the month following a TC+ sample for systems on quarterly or annual monitoring. Under the 

RTCR, a system that has a Level 1 trigger must conduct an assessment, and if a problem is 

found, the system must take corrective action. Under such circumstances, the advisory 

committee believed that additional samples collected the following month are appropriate to help 

recognize the problem if it still persists. Without the provision of additional monitoring, systems 

on annual or quarterly monitoring would not take any samples the following month. Systems 

having a Level 2 assessment are triggered into a monthly monitoring and therefore have less 

need for additional routine monitoring to indicate if a problem persists. 

For systems required to take the additional routine samples the following month (i.e., 

systems on quarterly or annual monitoring), the RTCR changes the requirement from taking a 

total of five routine samples to a requirement of just three routine samples. The advisory 

committee recognized that it is appropriate to drop from five to three samples the following 

month to reduce monitoring costs while still maintaining a substantial likelihood of identifying a 

problem if a problem persists. EPA recognizes that a reduction in the number of samples taken 

could also mean a reduction in the number of positive samples found. However, the reduction in 

the number of additional routine samples in conjunction with the new assessment and corrective 

action provisions of the RTCR (discussed in sections III.E.2 and III.E.3 of the RTCR preamble 

(USEPA 2010c)) leads to a rule that is ultimately more protective of public health (i.e., more E. 

coli MCL violations being prevented) and improvement in water quality (i.e., decrease in the 

TC+ and EC+ hit rates observed as shown by EA occurrence modeling results). 

For systems taking at least one sample monthly, the advisory committee recommended 

no additional routine samples for the following reason. Taking no additional routine samples the 

following month substantially reduces monitoring costs. The assessment and corrective action 

provisions will give systems the ability to identify and prevent the occurrence of problems. EA 
Economic Analysis for the Final RTCR 6-7 September 2012 

modeling results show that although there is a decrease in the number of E. coli MCL violations 

found with the decrease in the number of additional routine samples taken (i.e., going from five 

samples to one during the month following a TC+ sample), the assessment and corrective action 

provisions leads to more E. coli MCL violations being prevented compared to the 1989 TCR (see 

Exhibit 6.7 for more details). 

In addition, whenever a TC+ sample occurs during routine sampling, there is also a 

requirement to conduct repeat sampling to clarify if potential pathways to contamination persist. 

For systems serving 1,000 people or fewer, if a repeat sample is TC+, at least a Level 1 

assessment will be triggered. If a sanitary defect is found, the system is required to correct the 

sanitary defect. The absence of any repeat positive sample provides some indication that the 

problem is not persisting. For systems on monthly monitoring, these two conditions mitigate the 

need for additional routine sampling for the following month. 

Although the changes to the additional routine monitoring provisions mean that some 

fraction of triggers may be missed representing an increase in risk, EPA believes that the other 

provisions of the RTCR as described in this chapter compensate for that change and that, taken 

as a whole, the provisions of the RTCR provide for greater protection of public health. 

6.2.5 Annual Site Inspections 

The 1989 TCR does not include any requirements for annual site inspections. However, 

based on discussions with stakeholders, some states do perform annual site visits for any systems 

on an annual sampling schedule. 

Under the RTCR, GW NCWSs serving ≤1,000 people must, within one year of the 

compliance effective date, have an initial (and annually thereafter) visit by the state or an annual 

voluntary Level 2 assessment by a party approved by the state to remain on an annual monitoring 

schedule. Because of the cost differential between conducting annual site inspections and the 

alternative (quarterly monitoring), EPA has estimated that only those states that already 

voluntarily conduct annual site inspections under the 1989 TCR would do so under the RTCR. 

Therefore, no risk reduction is expected for these systems (and thus overall) from this rule 

component under the RTCR. 

The Alternative option does not allow systems to reduce to a frequency of annual 

monitoring and therefore does not include an annual site inspection requirement. However, based 

on discussions with stakeholders, those states that currently conduct annual site assessments 

under the 1989 TCR may no longer have the resources to continue the inspections and conduct 

quarterly monitoring under the Alternative option. For NCWSs on annual monitoring, the 

TCRDSAC believed that requiring a system to have an annual site visit or a Level 2 assessment 

provides at least an equivalent level of diagnosis of problems and vulnerabilities that might exist 

as compared to quarterly monitoring without an annual site visit. This tradeoff between annual 

monitoring with site inspections and three additional routine samples (i.e., quarterly monitoring 

with no site inspections) would potentially result in an increased risk for the Alternative option 

compared to the RTCR.
Economic Analysis for the Final RTCR 6-8 September 2012 

6.2.6 Assessments 

Under the 1989 TCR there is no explicit “assessment” required when TC+ results are 

observed. However, systems are required to notify the public and state under different scenarios. 

Specifically, a PWS must: 

 Report any acute MCL violation to the state no later than the end of the business 

after the system learns of a violation; 

 Notify the public within 24 hours of an acute MCL violation. 

 Notify the public within 30 days of a monthly/non-acute MCL violation; 

Under the RTCR and Alternative option,39 PWSs are required to perform and submit a 

Level 1 assessment if:

 Systems taking 40 or more samples per month have more than 5.0 percent TC+ 

samples; 

 Systems taking less than 40 samples per month have two or more TC+ samples in 

one month; or 

 A system fails to take all required repeat samples after a single TC+ sample 

A more detailed examination of the system, including its monitoring and operational 

practices (a Level 2 assessment), is required if a system has: 

 An E. coli MCL violation; 

 A second Level 1 treatment technique trigger within a rolling 12-month period, 

unless the first Level 1 treatment technique trigger was based on exceeding the 

allowable number of TC+ samples, the State has determined a likely reason for the 

TC+ samples that caused the initial Level 1 treatment technique trigger, and the 

State establishes that the system has fully corrected the problem; or 

 For PWSs with approved reduced annual monitoring, the system has a Level 1 

treatment technique trigger in two consecutive years.

Mandatory assessments are a new requirement under the RTCR and Alternative option, 

and also represent an increased focus on problem solving from the less defined investigations (if 

any) conducted under the 1989 TCR. Because of the more explicit requirements of the 

assessments, it is expected that more problems would be identified and resolved. As a result, the 

risk relative to the 1989 TCR is assumed to decrease. 

 

39 Requirements for the 1989 TCR, RTCR, and Alternative option are described in detail in Chapter 3 of this EA. 
Economic Analysis for the Final RTCR 6-9 September 2012 

6.2.7 Corrective Actions 

Corrective actions are not explicitly required under the 1989 TCR. However, responsible, 

well-operated systems do perform corrective actions based on investigations they perform (see 

Section 6.2.6) in response to positive samples. 

Under the RTCR and Alternative option, PWSs must correct any sanitary defects found 

during either a Level 1 or Level 2 assessment. For corrections not completed by the time of 

submission of the assessment form, systems must complete the corrective action(s) on a schedule 

determined by the state in consultation with the system. Systems are required to notify the state 

when they have completed each corrective action. Failure to implement a corrective action is 

considered a treatment technique violation, subject to public notification (PN). 

EPA does not have data on the existing rates at which corrective actions are completed 

under the 1989 TCR, so an assumption of the net change in the percentage of assessments 

resulting in corrective action (10 percent)40 is made for the RTCR and Alternative option as part 

of this EA and subsequent evaluation of changes in risk. Overall, increased protection provided 

by this net increase in corrective action as a result of requiring systems to implement a correction 

action through an enforceable mechanism would reduce risk under both the RTCR and 

Alternative option. 

6.2.8 Public Notification 

Monthly/Non-acute MCL Violations 

The 1989 TCR requires PN within 30 days of a monthly/non-acute MCL violation or 24 

hours of an acute MCL violation. 

Both the RTCR and Alternative option would require: 

 Tier 1 PN within 24 hours of an E. coli MCL violation; 

 Tier 2 PN within 30 days of a treatment technique violation; and; 

 Tier 3 PN within a year following either a routine monitoring violation or a 

reporting violation. 

However, under both the RTCR and Alternative option, the PN requirements for 

monthly/non-acute MCL violations would no longer be required (the RTCR and Alternative 

options do not include monthly/non-acute MCL violations). Since monthly/non-acute violations 

account for a large number of violations under the 1989 TCR, there is expected to be a large 

decrease in the number of notices presented to the public. If it is assumed that such notices 

provide information that aid in risk avoidance by water customers, risk may increase as a result 

of reducing this PN requirement to the extent that a risk exists. Because PWSs are no longer 

 

40 The 10 percent assumption is based on EPA discussions with stakeholders regarding experiences with 

implementing the 1989 TCR and the expected impact of RTCR. A sensitivity analysis evaluating alternative 

assumptions was conducted. Results of these analyses are discussed in Chapter 5 (section 5.3.3.1). 
Economic Analysis for the Final RTCR 6-10 September 2012 

required to send out notices for monthly/non-acute MCL violations or the monitoring results41

that triggered them under the 1989 TCR, there is also the potential that some PWSs may become 

less responsive in addressing TC hits or preventing them from occurring in the first place. 

The TCRDSAC evaluation of the 1989 TCR PN also concluded that the numbers of 

monthly/non-acute MCL violation notices that go out to the public are confusing. Unlike acute 

MCL violations associated with positive E. coli samples, monthly/non-acute MCL violations 

may have no connection to a direct health risk because TC+ samples do not indicate a direct 

threat to public health. To the extent that a high number of notices issued for monthly/non-acute 

MCL violations result in false alarms, consumers may not give appropriate attention to a notice 

of an acute MCL violation that indicates a greater potential risk to public health. Therefore, the 

EPA concluded, using best professional judgment informed by the TCRDSAC’s evaluation that 

risk may decrease through the elimination of the PN requirement for monthly/non-acute MCL 

violations under the RTCR and Alternative option. Additionally, resources used to issue high 

numbers of monthly/non-acute MCL violations and the time spent responding to customer 

inquiries about the violations may be better employed on other PWS issues which could result in 

further reduced risk. 

As discussed above, the influences on risk of eliminating the PN requirements for 

monthly/non-acute MCL violations may move risk in both directions. A decrease in the overall 

information received by consumers may result in reduced use of averting behaviors when they 

become necessary to avoid potentially contaminated drinking water, thus increasing potential 

risk. Conversely, too frequent notice of information that may not be directly related to a health 

risk may reduce confidence in the PWS, resulting in averting behavior that is not necessary, or 

may cause confusion or indifference that may result in consumers not taking averting actions 

when appropriate (i.e., ignoring an acute violation notice). Thus focusing on fewer, yet more 

“serious” notices may result in a decrease in potential risk. Risk may also decrease as a result of 

PWSs being able to better employ resources currently used on notice issuance and follow-up. 

EPA also considered the effect of Tier 2 PN requirements for treatment technique 

violations, which allow for up to a 30-day time delay between incurrence of the violation and 

notification to the public. This time delay could equate to some increased risk for the public 

relative to a scenario where an immediate notification was required. However, the change in risk 

relative to the 1989 TCR, which does not require assessments or corrective actions, is a decrease 

in risk. In allowing PWSs the flexibility to take up to a month to correct a sanitary defect before 

being required to issue PN, EPA is attempting to balance the potential public health benefits 

associated with having prompt notification for all treatment technique violations with the 

potential inefficiency and extra costs related to cases where the same level of expedience may 

not be necessary. Tier 1 PN is still required within 24 hours to address situations where an 

imminent health threat occurs. 

In summary, EPA assumes that there would not be an overall increase in risk by changing 

PN requirements for monthly/non-acute MCL violations under the RTCR, but given the 

 

41 Under the 1989 TCR, for systems taking fewer than 40 samples per month, a non-acute violation occurs if 2 or 

more samples are TC+; for systems taking 40 or more samples per month, a non-acute violation is triggered by >5 

percent of TC+ samples. 
Economic Analysis for the Final RTCR 6-11 September 2012 

contradictions in potential risk reductions the potential change in risk is best characterized as 

“unknown.”

Monitoring and Reporting Violations 

The TCRDSAC also evaluated the effects of revised PN requirements for monitoring and 

reporting violations under the RTCR and Alternative option and concluded that significant 

reductions in monitoring and reporting violations and associated costs may be realized through 

the regulatory framework of the RTCR. For the 1989 TCR, monitoring and reporting violations 

result in Tier 3 PN. Under the RTCR and Alternative option, monitoring violations are separate 

from the reporting violations, and the PN requirements for failing to take some types of samples 

are more stringent as compared to the monitoring and reporting violations under the 1989 TCR. 

For repeat sampling, a PWS that fails to take every required repeat sample following a routine 

EC+ sample must: 

 Initiate Tier 1 PN within 24 hours; 

 Initiate consultation with the state no later than 24 hours after learning of the 

violation, to determine additional PN requirements, if any; 

 Perform a level 2 assessment/corrective action: and 

 Increase to a minimum of monthly monitoring. 

For a PWS that fails to take every required repeat sample after any single TC+ sample, 

the PWS must perform a level 1 assessment/corrective action. Failure to perform a required 

assessment and/or corrective action results in a treatment technique violation (Tier 2) and a 

minimum of monthly monitoring. 

For routine and additional routine monitoring, a PWS that does not take every required 

routine sample, or every required additional routine sample, in a compliance period is still 

subject to Tier 3 PN; noncompliance with sampling requirements does not necessarily increase 

the likelihood that a PWS will be contaminated with fecal contamination and/or a waterborne 

pathogen and so does not present a direct or immediate public health risk. However, if the PWS 

has monitoring violations in 2 of 4 quarters (for systems on quarterly monitoring) or misses its 

required annual sample (for systems on annual monitoring), the PWS must revert to monitoring 

no less than monthly. 

Overall, the added PN stringency for monitoring violations is expected to decrease 

potential risk under the RTCR and Alternative option as PWSs opt to perform required sampling 

to avoid transition to increased monitoring requirements or other additional actions. 

Summary Exhibit 

The component discussions in Sections 6.2.1 through 6.2.8 above address the individual 

effects under each rule component on the various system types and sizes. The terms “increase,” 

“decrease,” and “no change” in Exhibit 6.1 indicate the direction of change in risk under the 

RTCR and Alternative option relative to the 1989 TCR. Risk may change for some system sizes 
Economic Analysis for the Final RTCR 6-12 September 2012

or types and not for others under a given rule component. In such cases, Exhibit 6.1 reflects the 

overall change in risk direction and does not necessarily apply to all types and sizes of systems. 
Economic Analysis for the Final RTCR 6-13 September 2012

Exhibit 6.1 Potential Changes in Risk under the RTCR and Alternative Option Relative to the 1989 TCR

Rule Component

Factors Leading to a Potential 

Increase in Risk

Factors Leading to a Potential Decrease in 

Risk

Overall Predicted Change in 

Risk

RTCR Alternative 

option RTCR Alternative

option RTCR Alternative 

option

Implementation 

Activities

None None None None No change No change

Routine 

Monitoring 

(Including 

Reduced 

Monitoring)

None None Increased stringency 

in requirements to 

qualify for reduced 

monitoring along with 

requirement to return 

to baseline monitoring 

upon loss of these 

criteria is expected to 

result in decreased 

risk (i.e., fewer PWSs 

will qualify and 

therefore more will 

monitor more 

frequently).

PWSs all monitor monthly 

in the first few years of 

implementation of the 

RTCR, which is an 

increase in sampling 

frequency for systems 

that monitor quarterly or 

annually under the 1989

TCR. After the first few 

years, systems may 

reduce to quarterly, but 

none may reduce to 

annual monitoring, 

creating a decrease in risk 

for systems on annual 

monitoring under the 1989

TCR.

Decrease Decrease

Repeat 

Monitoring

Required repeat 

samples reduced 

from 4 to 3 for 

systems serving 

<1,000 people

Required repeat 

samples reduced 

from 4 to 3 for 

systems serving 

<1,000 people

None None Increase Increase
Economic Analysis for the Final RTCR 6-14 September 2012

Rule Component

Factors Leading to a Potential 

Increase in Risk

Factors Leading to a Potential Decrease in 

Risk

Overall Predicted Change in 

Risk

RTCR Alternative 

option RTCR Alternative

option RTCR Alternative 

option

Additional 

Routine 

Monitoring

Additional routine 

samples are no 

longer required for 

PWSs monitoring 

monthly.

GW PWSs serving 

≤1,000 people 

would reduce 

additional routine 

samples from 5 to 

3.

Additional routine 

samples are no 

longer required 

for PWSs 

monitoring 

monthly.

GW PWSs 

serving ≤1,000 

people would 

reduce additional 

routine samples 

from 5 to 3.

None None Increase Increase

Annual Site Visits None (only states 

currently 

performing annual 

site visits are 

expected to 

continue)

Annual 

monitoring is not 

permitted under 

the Alternative 

option, so the 

protective benefit 

of the annual site 

visit is lost.

None (only states 

currently performing 

annual site visits are 

expected to continue)

None No change Increase

Assessments None None Mandatory 

assessments are a 

new requirement.

Mandatory assessments 

are a new requirement.

Decrease Decrease

Corrective 

Actions

None None Mandatory corrective 

actions are a new 

requirement.

Mandatory corrective 

actions are a new 

requirement. 

Decrease Decrease
Economic Analysis for the Final RTCR 6-15 September 2012 

Rule Component

Factors Leading to a Potential 

Increase in Risk

Factors Leading to a Potential Decrease in 

Risk

Overall Predicted Change in 

Risk

RTCR Alternative 

option RTCR Alternative

option RTCR Alternative 

option

Public Notification 

—Monthly/NonAcute MCL 

Violations

Reduction in 

available public 

information

Possible PWS 

complacency

Reduction in 

available public 

information

Possible PWS 

complacency

Less confusion (PN 

more in line with 

potential health risks)

PWS resources used 

more efficiently

Less confusion (PN more 

in line with potential 

health risks)

PWS resources used 

more efficiently

Unknown Unknown

Public Notification 

—Monitoring and 

Reporting 

Violations

None None Increased stringency 

of PNs motivates 

PWSs to conduct 

required sampling.

Increased stringency of 

PNs motivates PWSs to 

conduct required 

sampling.

Decrease Decrease

Overall Empty cell Empty cell Empty cell Empty cell Decrease Decrease

Note: 

1) Detailed discussion of the rationale for determinations of potential risk for each rule component is presented in Ch. 6 (Sections 6.2.1–6.2.8 above) of this EA. 

Implementation activities consist of administrative activities by PWSs and states to implement the rule. 

2) Assessment of potential changes in risk for monitoring components is an overall assessment. Potential changes (or static state) of risk for particular system 

sizes and types differ according to individual rule requirements and are discussed in Sections 6.2.1–6.2.8 above. Chapter 3 provides a detailed description of 

the rule components for all three regulatory options, and the Preamble to the RTCR provides additional discussion of the TCRDSAC process and the rationale 

underlying the structure of the regulatory options considered. 
Economic Analysis for the Final RTCR 6-16 September 2012 

6.2.9 Summary of Qualitative Benefits Analyses 

The discussions above describe relative risks in terms of individual components of the 

regulatory options. Based on the discussions presented above, EPA has used best professional 

judgment informed by the TCRDSAC to qualitatively estimate the potential changes in public 

health for each regulatory option, as compared with the 1989 TCR. These assessments were 

made with contributions from a wide range of drinking water experts, including public health 

scientists, engineers, administrators, and regulatory experts. The overall change in risk relative to 

the 1989 TCR is a result of the complex interactions of all rule components. As the discussion 

above shows, under repeat and additional routine monitoring provisions for the RTCR and 

Alternative option, there is a potential for increased risk for PWS customers because TC

monitoring frequency may be reduced for some PWSs. However, this increase is expected to be 

more than offset by potential decreases in risk from increased routine monitoring for some PWSs 

due to more stringent criteria to qualify and stay on reduced monitoring and the addition of the 

assessments and corrective action provisions that will find and fix problems identified by 

monitoring. 

The consensus opinion resulting from the TCRDSAC deliberations was that the RTCR 

would achieve a net risk reduction compared to the 1989 TCR. The committee applied best 

professional judgment in determining that the increased protection provided by the new 

requirements for implementing focused assessments and implementing appropriate corrective 

actions would more than offset any potential increase in risk introduced by the reduction in 

samples and other changes resulting from the RTCR. To present the potential for further 

reduction in risk due to the increased numbers of samples taken, especially in the first several 

years of implementation, the committee considered monthly monitoring for all systems, similar 

to that required under the Alternative option. However, the additional burden42 of requiring all 

PWSs to initially monitor on a monthly basis (regardless of PWS size or type) and limiting 

reduced monitoring to quarterly (disallowing annual monitoring) would fall disproportionately 

on small systems based on their proportionately large increase in activity under the RTCR.

6.3 Assessment of Predictive Analysis Results 

Based on discussions in and information developed for the TCRDSAC meetings 

(described in Chapter 3 of this EA), EPA anticipated prior to beginning this EA that the RTCR 

would not be a significant rule in terms of costs (i.e., less than $100 million annually). However, 

EPA considered the feasibility of performing a traditional risk assessment that would produce 

quantified estimates of costs, benefits, and net costs and benefits, as outlined in section 1412 

(b)(3)(C) of the Safe Drinking Water Act (SDWA). For this type of analysis, the minimum 

information requirements comprise data on contaminant occurrence; exposure rates in the 

population defined for the various pathways (i.e., water consumption, inhalation, and dermal 

contact); potential health effects associated with exposure to contaminated water; and a doseresponse relationship. A quantified benefits analysis would use this information to estimate the 

number of avoided cases of morbidity or mortality associated with the rule, which would then be 

valued in terms of saved lives and preserved quality of life and work capacity. 

 

42 Additional costs under the Alternative option are discussed Chapter 7 of this EA. 
Economic Analysis for the Final RTCR 6-17 September 2012 

For the RTCR EA, the available information includes data on the incidence of TC+ 

samples collected under the 1989 TCR over the 6-year period from 1998–2005, from which EPA 

selected one complete year (2005) to use for analyses in this EA, as explained in Section 4.2.2 of 

this EA. For the year 2005, EPA also has data on TC+ samples that subsequently test positive for 

E. coli (using EPA-approved standard methods available at that time). No other national 

occurrence data are available. 

As discussed in Chapter 2 of this EA, the presence of E. coli is an indication that the 

water contains fecal contamination. Some E. coli strains (or serotypes) such as E. coli O157:H7, 

for example, are pathogens. However, EPA recognizes that the EPA-approved standard methods 

available for E. coli do not typically identify the presence of the pathogenic E. coli strains, such 

as E. coli O157:H7. Thus, E. coli occurrence, as used in this EA, serves as an indication of fecal 

contamination but not necessarily pathogenic contamination. E. coli occurrence does not confer 

any significant quantitative information about the likelihood of health effects (e.g., acute 

gastrointestinal illness or chronic illnesses as described in Chapter 2 of this EA) from consuming 

drinking water contaminated with fecal indicator organisms. 

There are few data reporting the co-occurrence in a single sample of fecal indicator E. 

coli (assayed using EPA-approved standard methods) and pathogenic E. coli strains. One notable 

exception are the data reported by Cooley et al. (2007), which showed high concentrations of 

pathogenic E. coli strains in samples containing high concentrations of fecal indictor E. coli. 

These data are from streams and other poor quality surface waters surrounding California 

spinach fields associated with an E. coli O157:H7 foodborne outbreak. Data equivalent to these 

are not available from drinking water samples collected under the 1989 TCR. 

Absent any definitive data on co-occurrence of fecal indicator (E. coli) and pathogenic E. 

coli, EPA did not estimate the cases of morbidity or mortality avoided. Instead, EPA estimated 

changes in occurrence and the resulting changes in assessments and corrective actions performed 

for systems serving ≤4,100 people. For systems serving >4,100 people, EPA applied the 2007 

violations data to estimate the increase in effective corrective actions implemented. Discussion 

of reductions in risk, then, considers the change in occurrence and corrective actions 

implemented for systems serving ≤4,100 and the changes in corrective actions implemented for 

systems serving >4,100.43

For all systems, EPA also estimated the behavioral response of the regulated community 

based on projected occurrence rates or violations under the RTCR and Alternative option, 

including the frequency of Level 1 or Level 2 assessments and the type and number of corrective 

actions implemented by PWSs to address the problems identified. EPA expects that the effects of 

these changes on risk will be varied, as described in Section 6.3.1 below.

 

43 The rationale for using different metrics as proxies for risk reduction in systems serving ≤4,100 people and those 

serving >4,100 is explained in Chapters 4 and 5 of this EA. 
Economic Analysis for the Final RTCR 6-18 September 2012 

6.3.1 Assessment of Predictive Analysis Results for Systems Serving ≤4,100 People and 

Systems Serving >4,100 People 

Because the PWSs serving 4,100 people or fewer have a higher initial E. coli occurrence 

and will be triggered into more assessments and corrective actions than PWSs serving >4,100 

people, the increase in benefits for systems serving ≤4,100 people will be more evident as 

compared to the systems serving >4,100 people. In particular, model results suggest that 

customers of GW TNCWSs serving 100 or fewer people, which constitute approximately 40 

percent of PWSs, experience the most improvement in water quality under the RTCR. That is, 

the occurrence of E. coli is predicted to decrease more for these systems that for other systems 

types. 

6.3.1.1 Systems Serving ≤4,100 People 

For systems serving ≤4,100 people, EPA developed a model to simulate regulatory 

responses for a 30-year period of analysis, including years 1–5 in which GWR44 is in effect, 

years 3–5 in which the RTCR is being implemented, and years 6–30 during which RTCR 

requirements are also in effect. The 30-year modeled time period includes a total of 28 years of 

RTCR impacts post-promulgation. Although this EA considers benefits and costs for only 25 

years post-promulgation, the 30-year period was presented in Chapter 5 for broader 

consideration of the appropriateness of the model in terms of its results. The 25 years postpromulgation that are considered in this EA encompass years 3–27 of the 30-year modeled 

period. A complete description of the model is provided in Chapter 5 of this EA, and data 

sources used are described in Chapter 4. 

Output from the system simulation model for systems serving ≤4,100 people includes the 

following estimates for each year of analysis: 

 Samples taken (routine, additional routine, and repeat); 

 Number of positive results (TC+ and/or EC+) 

 Level 1 and Level 2 assessments conducted based on non-acute violations; 

 Level 2 assessments conducted based on acute violations; and 

 Corrective actions based on Level 1 assessments and Level 2 assessments. 

The results of analyses in terms of expected changes in hit rates (positive samples/totals 

samples taken) over time are presented in chapter 5 (Section 5.3.3) and Appendix B. Predicted 

TC+ hit rate results reflect the overall increase in water quality expected over time under the 

RTCR and Alternative option. Exhibits 6.2–6.4 present a summary of the additional endpoints 

listed above for the 25-year period of analysis following rule promulgation. 

 

44 Reductions in EC+ occurrence or violations are only attributable to the RTCR if they result from requirements of 

the RTCR regulatory options; reductions resulting from the GWR are not attributable to the RTCR and are not 

considered further in this chapter. As described in sections 4.2, 4.3, and 5.3 of this EA, GWR effects are 

incorporated to adjust source data to the appropriate baseline for this EA. 
Economic Analysis for the Final RTCR 6-19 September 2012 

As discussed earlier in this section, because a dose-response relationship between EC+ 

occurrence (i.e., acute violations) and illness is not available, EPA is focusing on changes in EC+ 

occurrence. EPA assumes that reduced occurrence in PWSs should generally correlate with a 

reduction in risk of contamination to PWS drinking water. Therefore, the acute violation rates 

predicted under the RTCR and Alternative option (Exhibits 6.3–6.4) represent a level of risk of 

contamination that is reduced from that predicted under the 1989 TCR (Exhibit 6.2). The 

numbers of predicted acute violations have two major drivers. First, improvements in water 

quality are predicted to result in fewer acute violations. Second, the monitoring frequency 

impacts the number of acute violations found, regardless of water quality. Both decreases in 

acute violations attributable to water quality improvements and increases due to additional 

diagnostic ability of more samples taken result in reduced risk. The combination of these two 

influences in the predictive model means that the risk is expected to be lower even though the 

number of predicted acute violations may actually be higher or lower than under the 1989 TCR 

as reflected in exhibits 6.2–6.4. This concept is discussed in the uncertainty analysis in Section 

6.4 of this chapter. 

The changes in the steady state estimates of annual acute violations from the 1989 TCR 

to the RTCR and Alternative option are shown in Exhibit 6.5 and 6.6 in absolute numbers and as 

a percentage change from the 1989 TCR, respectively. The steady state in the model refers to the 

period beginning in years 7 (CWSs) and 9 (NCWSs) following promulgation, after the 

proportions of systems sampling on monthly, quarterly, or annual regimens are adjusted 

following a period of assessment.45Systems that qualify for reduced monitoring will begin their 

new regimens in years 7 and 9 after promulgation, respectively, for CWSs and NCWSs. The 

estimates shown in Exhibit 6.5 for systems serving ≤4,100 people are from the predictive model 

and reflect the average annual estimates for the 25-year period of analysis, which includes 3 

years of initial implementation followed by 22 years in which new rule requirements are also in 

effect. To accurately reflect the average annual results under this schedule, the model output for 

the 22 years of additional activity following the 3 years of initial implementation is divided by 

22, rather than the entire 25 years, since that would distort the results downward. The steady 

state reductions in the number of annual acute violations found under the RTCR and Alternative 

option primarily reflect the benefits of corrective actions under these two options in preventing 

many of the acute violations that would otherwise occur over this period. 

These results show that under the RTCR, no subgroups are predicted to experience an 

increase in annual acute violations. While most categories of systems/sizes would experience a 

decrease in predicted numbers of violations under the Alternative option, four categories would 

 

45 The effective date of the RTCR occurs after 3 years of initial implementation, that is, at the start of year 4 postpromulgation. For CWSs, years 4–6 post-promulgation are the period of assessment for potential to move to reduced 

monitoring; for NCWSs, years 4–8 post-promulgation are the period of assessment for reduced monitoring. Under 

the Alternative option, this period of assessment occurs in years 4–8 post-promulgation for all PWSs. In the 

aggregate, the steady state regarding reduced monitoring schedules under the Alternative option begins in year 9 

post-promulgation. Chapter 5 provides a description of the criteria used to estimate the steady percent of systems 

qualifying for reduced monitoring under the RTCR and Alternative option. In this chapter, these transitions are 

presented on the 30-year scale of the modeling period, in which years 1–3 are the baseline occurrence for the 1989 

TCR with the GWR effects and are pre-promulgation. Exhibits 5.16–5.21 show that the steady state begins in model 

year 9 (CWSs) and model year 11 (NCWSs). This modeling is not performed for systems operating under the 1989 

TCR; they are assumed to remain on the initial schedule presented in Chapter 4 (baseline). 
Economic Analysis for the Final RTCR 6-20 September 2012 

actually experience an increase (a positive percent value in Exhibit 6.6): GW NTNCWSs serving 

501–1,000 people and GW TNCWSs serving ≤100, 101–500, and 501–1,000 people. It is 

important to note that in two of those cases, the absolute increases in annual acute violations 

predicted under either option is very small (≤1 annual acute violation as shown in Exhibit 6.5), 

but translate into observable percentage changes in Exhibit 6.6. The two categories with an 

increase of greater than one annual acute violation are the GW TNCWSs systems serving ≤100 

people and those serving 101–500 people, for which increases of approximately 52 and 16 

annual acute violations, respectively, are predicted. For these TNCWSs under the Alternative 

option, increased monitoring is expected to lead to an overall increase in annual acute violations 

(and is also the driver of the greater total number of annual acute violations predicted). 

As discussed earlier, a decrease in acute violations may be caused by an improvement in 

water quality, which in this model would result from an increased number of effective corrective 

actions being implemented (i.e., occurrence events are “prevented”). An increase in acute 

violations can be attributable to a decrease in water quality or a PWS improving its ability to 

detect more issues (e.g., through more sampling). Alternatively, a decrease in acute violations 

could be caused by a decreased ability in PWSs to detect the occurrence of TC/EC because of a 

reduced sampling schedule, resulting in undetected or “missed” occurrence events. Section 6.4 of 

this chapter presents a stepwise analysis to discern the relative significance of the effects of 

reduced additional routine samples and increased corrective action efficacy as shown by 

predictions of “prevented”, “found”, and “missed” acute violations under the RTCR. 

6.3.1.2 Systems Serving >4,100 People 

The number of acute and non-acute MCL violations for a given group (based on system 

type and water source) of PWSs serving >4,100 people was estimated using 2005 Safe Drinking 

Water Information System/Federal Version (SDWIS/FED) data (USEPA, 2005). These estimates 

were used to determine the number of Level 1 and Level 2 assessments and associated corrective 

actions triggered for systems serving >4,100 in the period of analysis. EPA made a simplifying 

assumption that for PWSs serving >4,100 people the number of annual assessment triggers 

would remain constant throughout the 22 years following the 3 years of initial implementation of 

the RTCR. As assumed in the occurrence model for systems serving ≤4,100 people, this analysis 

also assumes that systems responding to a Level 2 assessment trigger (i.e., an acute MCL 

violation under the 1989 TCR) would identify and specifically address the cause of the 

contamination at a rate increased by 10 percent under the RTCR and Alternative option 

compared to the 1989 TCR.46

Exhibits 6.2–6.4, described in Section 6.3.1.1 for systems serving ≤4,100 people, also 

include the number of activities (assessments and corrective actions) EPA expects PWSs to 

implement under each of the regulatory options considered for systems serving >4,100. Any 

reduction in risk is estimated to derive from the additional corrective actions predicted per the 

explanation above. Exhibit 6.5 also reflects that EPA is not quantifying any potential change in 

 

46The 10 percent assumption is based on EPA discussions with stakeholders regarding experiences with 

implementing the 1989 TCR and the expected impact of RTCR. A sensitivity analysis evaluating alternative 

assumptions was conducted. Results of these analyses are discussed in Chapter 5 (section 5.3.3.1). 

 
Economic Analysis for the Final RTCR 6-21 September 2012 

the number of annual acute violations for PWSs serving >4,100 people during the period. This 

assumption simplifies the analysis and is consistent with EPA’s understanding based on 

TCRDSAC deliberations and best professional judgment that systems serving >4,100 are at a 

relatively steady state with regard to operations. These systems have been in a position relative to 

systems serving ≤4,100 people to diagnose more and address the cause of acute violations more, 

and they have likely had more resources to apply in maintaining and updating their systems on a 

regular basis. Therefore, EPA does not believe that systems serving >4,100 will make many 

changes based on RTCR implementation, or that they will experience large changes in their 

occurrence rates for TC and E. coli after RTCR promulgation. 
Economic Analysis for the Final RTCR 6-22 September 2012 

Exhibit 6.2 Predicted Outcomes (25-Year Period of Analysis) under the 1989 TCR 

A B C D E F G H I J=E+G+H

Community Water Systems (CWSs) - SW

≤100 1,170 304,247 23,167 18,698 525 - 157 184 - 865

101 - 500 2,150 562,198 27,009 21,684 649 - 167 111 - 927

501-1,000 1,173 306,605 15,334 12,299 361 - 102 63 - 526

1,001-4,100 2,938 1,921,237 55,132 33,729 954 - 162 149 - 1,265 

4,101-33,000 3,164 10,636,296 - 186,729 2,152 - 197 - - 2,349 

33,001-96,000 720 11,058,960 - 194,149 534 - 56 - - 590

96,001-500,000 308 10,190,400 - 178,901 233 - 24 - - 257

500,001-1 Million 31 2,019,600 - 35,456 22 - - - - 22

> 1 Million 17 1,686,960 - 29,616 - - - - - -

Totals 11,671 38,686,502 120,642 711,259 5,429 - 865 507 - 6,801 

Community Water Systems (CWSs) - GW

≤100 11,938 2,815,951 286,073 194,462 9,772 - 1,141 5,383 - 16,295 

101 - 500 13,892 3,344,578 243,895 171,252 8,169 - 1,025 4,214 - 13,408 

501-1,000 4,467 1,072,202 70,803 51,673 2,250 - 284 1,050 - 3,584 

1,001-4,100 6,443 3,997,293 160,710 100,618 3,545 - 477 2,808 - 6,831 

4,101-33,000 3,156 9,145,224 - 230,201 4,545 - 263 - - 4,807 

33,001-96,000 335 4,884,000 - 122,938 656 - 53 - - 709

96,001-500,000 63 1,945,680 - 48,976 129 - 10 - - 139

500,001-1 Million 4 253,440 - 6,380 - - - - - -

> 1 Million 3 269,280 - 6,778 - - - - - -

Totals 40,301 27,727,648 761,481 933,279 29,066 - 3,253 13,455 - 45,773 

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

≤100 250 65,018 4,910 3,991 98 - 35 77 - 210

101 - 500 253 66,045 3,735 3,011 88 - 29 40 - 157

501-1,000 88 22,976 1,278 1,029 30 - 9 13 - 52

1,001-4,100 72 41,759 2,142 1,348 42 - 19 37 - 98

4,101-33,000 22 50,424 - 1,628 5 - - - - 5

33,001-96,000 2 34,320 - 1,108 - - - - - -

96,001-500,000 1 31,680 - 1,023 - - - - - -

500,001-1 Million - - - - - - - - - -

> 1 Million - - - - - - - - - -

Totals 688 312,223 12,065 13,138 262 - 93 167 - 522

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

≤100 8,826 971,538 128,775 84,992 5,581 - 856 3,829 - 10,267 

101 - 500 6,613 725,785 66,525 43,597 3,130 - 447 1,273 - 4,849 

501-1,000 1,718 190,649 16,037 10,680 744 - 95 298 - 1,136 

1,001-4,100 812 460,470 28,214 17,790 818 - 169 974 - 1,961 

4,101-33,000 70 153,648 - 5,936 123 - 9 - - 132

33,001-96,000 2 23,760 - 918 4 - - - - 4

96,001-500,000 - - - - - - - - - -

500,001-1 Million - - - - - - - - - -

> 1 Million - - - - - - - - - -

Totals 18,041 2,525,850 239,551 163,913 10,400 - 1,577 6,373 - 18,350 

Transient Noncommunity Water Systems (TNCWSs) - SW

≤100 1,339 345,401 40,475 33,065 1,093 - 430 780 - 2,302 

101 - 500 497 128,156 15,261 12,454 410 - 170 320 - 900

501-1,000 88 22,691 2,704 2,207 67 - 28 47 - 142

1,001-4,100 67 40,151 4,155 2,707 92 - 50 128 - 270

4,101-33,000 18 40,656 - - 8 - - - - 8

33,001-96,000 - - - - - - - - - -

96,001-500,000 - - - - - - - - - -

500,001-1 Million - - - - - - - - - -

> 1 Million 1 102,960 - - - - - - - -

Totals 2,010 680,015 62,596 50,434 1,670 - 677 1,275 - 3,622 

Transient Noncommunity Water Systems (TNCWSs) - GW

≤100 60,200 4,493,808 905,554 600,315 44,730 - 6,649 25,425 - 76,805 

101 - 500 19,275 1,614,924 316,238 210,714 14,530 - 2,089 8,864 - 25,483 

501-1,000 1,963 177,264 32,730 22,064 1,477 - 221 896 - 2,595 

1,001-4,100 617 335,283 29,957 19,113 927 - 186 1,138 - 2,251 

4,101-33,000 67 156,288 - 8,909 116 - 4 - - 120

33,001-96,000 2 34,320 - 1,956 - - - - - -

96,001-500,000 1 26,400 - 1,505 - - - - - -

500,001-1 Million 1 63,360 - 3,612 - - - - - -

> 1 Million - - - - - - - - - -

Totals 82,126 6,901,647 1,284,478 868,188 61,780 - 9,149 36,324 - 107,253 

Grand Total 154,837 76,833,885 2,480,814 2,740,210 108,608 - 15,613 58,102 - 182,322 

Number of 

Non-Acute 

Violation 

Assessments 

(Single 

Violations)

Number of 

Acute 

Violation 

Assessments

Number of 

Non-Acute 

Violation 

Assessments

(Multiple 

Violations)

Number of 

Corrective 

Actions

(based on 

Single NonAcute Violation 

Assessment)

Source: 

1) Appendix A, Exhibit A.1.z.

2) Predicted outcomes for systems serving ≤4,100 are output from the occurrence model detailed in Ch. 5 of this EA; predicted outcomes for systems serving >4,100 people are from the 

larger systems model based on 2007 SDWIS violations data.

Notes:

1) For modeling purposes, EPA estimated only the net change in the number of corrective actions performed under the RTCR and Alternative option compared to the 1989 TCR. Because 

only the net change in the number of corrective actions is estimated, no additional corrective actions are modeled for the 1989 TCR (it is assumed that PWSs are already performing some 

corrective actions under the 1989 TCR).

2) Results differ slightly from those presented in Ex. 5.10 – 5.15 because they are capturing slightly different time periods of the 30 modeled years. For completeness in discussing the 

simulation model, Chapter 5 exhibits show 30 years of results, beginning w ith 5 years of GWR in effect, the last 3 of w hich also include initial implementation of the RTCR, follow ed by 25 

years of RTCR in effect. Alternatively, Ex. 6.2 – 6.4 include the modeled period that encompasses years 3 - 27 of the 30-year modeling period, including the 3 years of RTCR initial 

implementation and the 22 years that follow of RTCR in effect. During the 3 years of RTCR initial implementation, under either the RTCR or Alternative option, systems are still w orking 

under the requirements of the 1989 TCR and GWR w hile incurring costs for the initial implementation activities of the new rule requirements. 

Number of 

Routine 

Monitoring 

Samples

Number of 

Additional 

Routine 

Monitoring 

Samples Tier 2 PNs

PWS Size

(Population

Served)

PWSs 

Subject 

to 1989 

TCR

Number of 

Repeat 

Monitoring 

Samples

Number of 

Corrective 

Actions

(based on 

Acute and 

Multiple NonAcute Violation 

Assessments)
Economic Analysis for the Final RTCR 6-23 September 2012 

Exhibit 6.3 Predicted Outcomes (25-Year Period of Analysis) for the RTCR 

A B C D E F G H I J=E+H

Community Water Systems (CWSs) - SW

≤100 1,170 308,880 - 13,764 400 36 100 102 21 501

101 - 500 2,150 567,600 - 15,660 539 56 119 75 20 615

501-1,000 1,173 309,672 - 8,708 277 27 75 40 12 317

1,001-4,100 2,938 1,951,224 - 33,326 920 95 146 132 29 1,052

4,101-33,000 3,164 10,636,296 - 181,661 2,152 215 197 - 20 2,152

33,001-96,000 720 11,058,960 - 188,880 534 53 56 - 6 534

96,001-500,000 308 10,190,400 - 174,046 233 23 24 - 2 233

500,001-1 Million 31 2,019,600 - 34,493 22 2 - - - 22

> 1 Million 17 1,686,960 - 28,812 - - - - - -

Totals 11,671 38,729,592 - 679,350 5,076 507 717 349 110 5,425

Community Water Systems (CWSs) - GW

≤100 11,938 2,870,075 8,760 156,897 8,004 791 853 3,523 398 11,527

101 - 500 13,892 3,391,200 6,127 136,906 6,502 669 696 2,399 335 8,901

501-1,000 4,467 1,085,730 1,844 39,659 1,780 168 188 626 85 2,406

1,001-4,100 6,443 4,079,328 - 96,939 3,208 318 342 1,705 206 4,913

4,101-33,000 3,156 9,145,224 - 217,321 4,545 454 263 - 26 4,545

33,001-96,000 335 4,884,000 - 116,060 656 66 53 - 5 656

96,001-500,000 63 1,945,680 - 46,236 129 13 10 - 1 129

500,001-1 Million 4 253,440 - 6,023 - - - - - -

> 1 Million 3 269,280 - 6,399 - - - - - -

Totals 40,301 27,923,956 16,731 822,439 24,824 2,480 2,405 8,253 1,056 33,077

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

≤100 250 66,000 - 3,040 75 8 28 41 7 116

101 - 500 253 66,792 - 2,169 69 7 19 24 4 93

501-1,000 88 23,232 - 756 24 2 6 9 2 33

1,001-4,100 72 42,768 - 1,228 37 4 13 23 4 59

4,101-33,000 22 50,424 - 1,448 5 0 - - - 5

33,001-96,000 2 34,320 - 985 - - - - - -

96,001-500,000 1 31,680 - 910 - - - - - -

500,001-1 Million - - - - - - - - - -

> 1 Million - - - - - - - - - -

Totals 688 315,216 - 10,536 209 22 67 98 17 306

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

≤100 8,826 932,025 48,142 68,123 4,797 493 559 2,010 254 6,807

101 - 500 6,613 678,688 25,630 35,860 2,794 271 315 757 107 3,552

501-1,000 1,718 180,145 6,166 8,601 675 66 79 168 24 843

1,001-4,100 812 473,352 - 15,887 690 68 114 530 65 1,221

4,101-33,000 70 153,648 - 5,157 123 12 9 - 1 123

33,001-96,000 2 23,760 - 797 4 0 - - - 4

96,001-500,000 - - - - - - - - - -

500,001-1 Million - - - - - - - - - -

> 1 Million - - - - - - - - - -

Totals 18,041 2,441,617 79,938 134,426 9,084 912 1,077 3,466 450 12,550

Transient Noncommunity Water Systems (TNCWSs) - SW

≤100 1,339 353,496 - 23,122 796 76 250 425 66 1,221

101 - 500 497 131,208 - 8,192 278 27 90 154 25 432

501-1,000 88 23,232 - 1,533 50 5 17 25 4 75

1,001-4,100 67 42,240 - 2,312 73 7 29 69 10 142

4,101-33,000 18 40,656 - 2,225 8 1 - - - 8

33,001-96,000 - - - - - - - - - -

96,001-500,000 - - - - - - - - - -

500,001-1 Million - - - - - - - - - -

> 1 Million 1 102,960 - 5,636 - - - - - -

Totals 2,010 693,792 - 43,020 1,204 116 386 674 105 1,878

Transient Noncommunity Water Systems (TNCWSs) - GW

≤100 60,200 6,076,163 446,166 631,105 47,190 4,755 5,477 20,628 2,593 67,818

101 - 500 19,275 1,940,946 135,822 194,697 13,780 1,363 1,608 5,694 799 19,474

501-1,000 1,963 206,130 14,078 20,078 1,396 143 177 585 76 1,982

1,001-4,100 617 348,480 - 16,027 773 77 117 638 76 1,412

4,101-33,000 67 156,288 - 7,188 116 12 4 - 0 116

33,001-96,000 2 34,320 - 1,578 - - - - - -

96,001-500,000 1 26,400 - 1,214 - - - - - -

500,001-1 Million 1 63,360 - 2,914 - - - - - -

> 1 Million - - - - - - - - - -

Totals 82,126 8,852,088 596,065 874,801 63,256 6,349 7,383 27,546 3,544 90,801

Grand Total 154,837 78,956,260 692,734 2,564,572 103,653 10,386 12,035 40,385 5,282 144,038

Number of 

Level 2 

Assessments 

(based on 

Acute 

Violations)

Number of 

Level 2 

Assessments 

(based on nonacute 

triggers)

Number of 

Corrective 

Actions (based 

on Level 1 

Assessments)

Number of 

Repeat 

Monitoring 

Samples

Number of 

Routine 

Monitoring 

Samples

Source: 

1) Appendix A, Exhibit A.2.z.

2) Predicted outcomes for systems serving ≤4,100 are output from the occurrence model detailed in Ch. 5 of this EA; predicted outcomes for systems serving >4,100 people are from the 

larger systems model based on 2007 SDWIS violations data.

Notes:

1) Estimates of the number of assessments and corrective actions are net increases in activity predicted to occur under the RTCR relative to the 1989 TCR; estimates of “zero” reflect that no 

additional such activity occurs as compared to baseline (the 1989 TCR). 

2) Results differ slightly from those presented in Ex. 5.10 – 5.15 because they are capturing slightly different time periods of the 30 modeled years. For completeness in discussing the 

simulation model, Chapter 5 exhibits show 30 years of results, beginning w ith 5 years of GWR in effect, the last 3 of w hich also include initial implementation of the RTCR, follow ed by 25 

years of RTCR in effect. Alternatively, Ex. 6.2 – 6.4 include the modeled period that encompasses years 3 - 27 of the 30-year modeling period, including the 3 years of RTCR initial 

implementation and the 22 years that follow of RTCR in effect. During the 3 years of RTCR initial implementation, under either the RTCR or Alternative option, systems are still w orking under the 

requirements of the 1989 TCR and GWR w hile incurring costs for the initial implementation activities of the new rule requirements. 

Number of 

Additional 

Routine 

Monitoring 

Samples

PWS Size

(Population

Served)

PWSs 

Subject 

to RTCR

Level 1 and 

Level 2 (based 

on non-acute 

triggers) 

Assessments

Number of 

Corrective 

Actions (based 

on Level 2 

Assessments)

Number of 

Level 1 

Assessments
Economic Analysis for the Final RTCR 6-24 September 2012 

Exhibit 6.4 Predicted Outcomes (25-Year Analysis Period) for the Alternative 

Option 

A B C D E F G H I J=E+H

Community Water Systems (CWSs) - SW

≤100 1,170 308,880 - 13,764 400 36 100 102 21 501

101 - 500 2,150 567,600 - 15,660 539 56 119 75 20 615

501-1,000 1,173 309,672 - 8,708 277 27 75 40 12 317

1,001-4,100 2,938 1,951,224 - 33,326 920 95 146 132 29 1,052

4,101-33,000 3,164 10,636,296 - 181,661 2,152 215 197 - 20 2,152

33,001-96,000 720 11,058,960 - 188,880 534 53 56 - 6 534

96,001-500,000 308 10,190,400 - 174,046 233 23 24 - 2 233

500,001-1 Million 31 2,019,600 - 34,493 22 2 - - - 22

> 1 Million 17 1,686,960 - 28,812 - - - - - -

Totals 11,671 38,729,592 - 679,350 5,076 507 717 349 110 5,425

Community Water Systems (CWSs) - GW

≤100 11,938 2,908,469 7,545 158,439 7,871 812 926 3,272 432 11,143

101 - 500 13,892 3,428,876 5,264 137,959 6,495 667 747 2,543 322 9,038

501-1,000 4,467 1,098,488 1,616 39,580 1,772 174 203 607 83 2,379

1,001-4,100 6,443 4,079,328 - 96,939 3,208 318 342 1,705 206 4,913

4,101-33,000 3,156 9,145,224 - 217,321 4,545 454 263 - 26 4,545

33,001-96,000 335 4,884,000 - 116,060 656 66 53 - 5 656

96,001-500,000 63 1,945,680 - 46,236 129 13 10 - 1 129

500,001-1 Million 4 253,440 - 6,023 - - - - - -

> 1 Million 3 269,280 - 6,399 - - - - - -

Totals 40,301 28,012,784 14,425 824,956 24,675 2,504 2,544 8,127 1,077 32,802

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

≤100 250 66,000 - 3,040 75 8 28 41 7 116

101 - 500 253 66,792 - 2,169 69 7 19 24 4 93

501-1,000 88 23,232 - 756 24 2 6 9 2 33

1,001-4,100 72 42,768 - 1,228 37 4 13 23 4 59

4,101-33,000 22 50,424 - 1,448 5 0 - - - 5

33,001-96,000 2 34,320 - 985 - - - - - -

96,001-500,000 1 31,680 - 910 - - - - - -

500,001-1 Million - - - - - - - - - -

> 1 Million - - - - - - - - - -

Totals 688 315,216 - 10,536 209 22 67 98 17 306

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

≤100 8,826 1,314,175 36,965 91,416 5,673 562 723 3,390 399 9,063

101 - 500 6,613 976,627 19,382 48,269 3,551 356 446 1,333 183 4,884

501-1,000 1,718 249,760 4,802 11,817 814 81 99 298 41 1,112

1,001-4,100 812 473,352 - 15,887 690 68 114 530 65 1,221

4,101-33,000 70 153,648 - 5,157 123 12 9 - 1 123

33,001-96,000 2 23,760 - 797 4 0 - - - 4

96,001-500,000 - - - - - - - - - -

500,001-1 Million - - - - - - - - - -

> 1 Million - - - - - - - - - -

Totals 18,041 3,191,322 61,149 173,343 10,855 1,080 1,393 5,551 689 16,406

Transient Noncommunity Water Systems (TNCWSs) - SW

≤100 1,339 353,496 - 23,122 796 76 250 425 66 1,221

101 - 500 497 131,208 - 8,192 278 27 90 154 25 432

501-1,000 88 23,232 - 1,533 50 5 17 25 4 75

1,001-4,100 67 42,240 - 2,312 73 7 29 69 10 142

4,101-33,000 18 40,656 - 2,225 8 1 - - - 8

33,001-96,000 - - - - - - - - - -

96,001-500,000 - - - - - - - - - -

500,001-1 Million - - - - - - - - - -

> 1 Million 1 102,960 - 5,636 - - - - - -

Totals 2,010 693,792 - 43,020 1,204 116 386 674 105 1,878

Transient Noncommunity Water Systems (TNCWSs) - GW

≤100 60,200 9,524,123 333,524 912,589 57,597 5,737 7,796 37,532 4,450 95,129

101 - 500 19,275 3,021,771 104,732 282,740 17,358 1,616 2,441 10,924 1,337 28,282

501-1,000 1,963 304,534 10,412 27,932 1,661 163 230 1,015 123 2,676

1,001-4,100 617 348,480 - 16,027 773 77 117 638 76 1,412

4,101-33,000 67 156,288 - 7,188 116 12 4 - 0 116

33,001-96,000 2 34,320 - 1,578 - - - - - -

96,001-500,000 1 26,400 - 1,214 - - - - - -

500,001-1 Million 1 63,360 - 2,914 - - - - - -

> 1 Million - - - - - - - - - -

Totals 82,126 13,479,275 448,667 1,252,181 77,506 7,605 10,589 50,109 5,986 127,615

Grand Total 154,837 84,421,981 524,241 2,983,387 119,526 11,834 15,695 64,908 7,983 184,433

Number of 

Level 2 

Assessments 

(based on nonacute 

triggers)

Number of 

Corrective 

Actions (based 

on Level 1 

Assessments)

Number of 

Routine 

Monitoring 

Samples

Number of 

Additional 

Routine 

Monitoring 

Samples

Source: 

1) Appendix A, Exhibit A.3.z.

2) Predicted outcomes for systems serving ≤4,100 are output from the occurrence model detailed in Ch. 5 of this EA; predicted outcomes for systems serving >4,100 people are from the larger 

systems model based on 2007 SDWIS violations data.

Notes:

1) Estimates of the number of assessments and corrective actions are net increases in activity predicted to occur under the Alternative option relative to the 1989 TCR; estimates of “zero” 

reflect that no additional such activity occurs as compared to baseline (the 1989 TCR). 

2) Results differ slightly from those presented in Ex. 5.10 – 5.15 because they are capturing slightly different time periods of the 30 modeled years. For completeness in discussing the simulation 

model, Chapter 5 exhibits show 30 years of results, beginning w ith 5 years of GWR in effect, the last 3 of w hich also include initial implementation of the RTCR, follow ed by 25 years of RTCR in 

effect. Alternatively, Ex. 6.2 – 6.4 include the modeled period that encompasses years 3 - 27 of the 30-year modeling period, including the 3 years of RTCR initial implementation and the 22 years 

that follow of RTCR in effect. During the 3 years of RTCR initial implementation, under either the RTCR or Alternative option, systems are still w orking under the requirements of the 1989 TCR and 

GWR w hile incurring costs for the initial implementation activities of the new rule requirements. 

Number of 

Level 1 

Assessments

Level 1 and 

Level 2 (based 

on non-acute 

triggers) 

Assessments

PWS Size

(Population

Served)

PWSs 

Subject to 

Alternative 

Option

Number of 

Repeat 

Monitoring 

Samples

Number of 

Corrective 

Actions (based 

on Level 2 

Assessments)

Number of 

Level 2 

Assessments 

(based on 

Acute 

Violations)
Economic Analysis for the Final RTCR 6-25 September 2012 

Exhibit 6.5 Predicted Average Annual Acute Violations by Regulatory Option and 

System Type1 

PWS Size

(Population

Served)

Number of 

Systems 1989 TCR RTCR

Alternative 

Option

≤100 1,170 7 5 5

101-500 2,150 8 5 5

501-1,000 1,173 5 3 3

1,001-4,100 2,938.0 7.4 6.6 6.6

4,101-33,000 3,164 9 9 9

33,001-96,000 720 3 3 3

96,001-500,000 308 1 1 1

500,001-1 Million 31 0 0 0

> 1 Million 17 0 0 0

Totals 11,671 39 33 33

≤100 11,938 52 39 42

101-500 13,892 47 32 34

501-1,000 4,467 13 9 9

1,001-4,100 6,443 22 16 16

4,101-33,000 3,156 12 12 12

33,001-96,000 335 2 2 2

96,001-500,000 63 0 0 0

500,001-1 Million 4 0 0 0

> 1 Million 3 0 0 0

Totals 40,301 148 109 116

≤100 250 2 1 1

101-500 253 1.3 0.9 0.9

501-1,000 88 0.4 0.3 0.3

1,001-4,100 72 0.9 0.6 0.6

4,101-33,000 22 0 0 0

33,001-96,000 2 0 0 0

96,001-500,000 1 0 0 0

500,001-1 Million 0 0 0 0

> 1 Million 0 0 0 0

Totals 688 4 3 3

≤100 8,826 39 25 33

101-500 6,613 20.31 14.31 20.29

501-1,000 1,718 4.31 3.61 4.51

1,001-4,100 812 8 5 5

4,101-33,000 70 0 0 0

33,001-96,000 2 0 0 0

96,001-500,000 0 0 0 0

500,001-1 Million 0 0 0 0

> 1 Million 0 0 0 0

Totals 18,041 72 49 63

≤100 1,339 20 11 11

101-500 497 8 4 4

501-1,000 88.00 1.25 0.79 0.79

1,001-4,100 67.0 2.3 1.3 1.3

4,101-33,000 18 0 0 0

33,001-96,000 0 0 0 0

96,001-500,000 0 0 0 0

500,001-1 Million 0 0 0 0

> 1 Million 1 0 0 0

Totals 2,010 31 18 18

≤100 60,200 302 249 354

101-500 19,275 94.93 73.11 110.96

501-1,000 1,963 10.07 8.04 10.47

1,001-4,100 617 8 5 5

4,101-33,000 67 0 0 0

33,001-96,000 2 0 0 0

96,001-500,000 1 0 0 0

500,001-1 Million 1 0 0 0

> 1 Million 0 0 0 0

Totals 82,126 416 336 481

Grand Total 154,837 710 547 713

Source: 

Output from RTCR models as described in Sections 5.3 and 5.4 of this EA for 

systems serving <4,100 people and systems serving >4,100 people. 

Note:

Monitoring activates under RTCR begin in year 4 after rule promulgation. Therefore 

to represent the average annual acute violations occurring over the 25-year modeled 

time period, the total number of violations is divided by 22 years where monitoring 

activities are conducted.

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

Transient Noncommunity Water Systems (TNCWSs) - SW

Transient Noncommunity Water Systems (TNCWSs) - GW

Community Water Systems (CWSs) - SW

Community Water Systems (CWSs) - GW

Nontransient Noncommunity Water Systems (NTNCWSs) - SW
Economic Analysis for the Final RTCR 6-26 September 2012 

Exhibit 6.6 Predicted Change in Average Annual Acute Violations by Regulatory 

Option and System Type 

PWS Size

(Population

Served) RTCR Alternative Option

≤100 -36% -36%

101-500 -29% -29%

501-1,000 -27% -27%

1,001-4,100 -10% -10%

Totals -17% -17%

≤100 -25% -19%

101-500 -32% -27%

501-1,000 -34% -29%

1,001-4,100 -28% -28%

Totals -26% -22%

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

≤100 -20% -20%

101-500 -35% -35%

501-1,000 -32% -32%

1,001-4,100 -30% -30%

Totals -28% -28%

≤100 -35% -15%

101-500 -30% 0%

501-1,000 -16% 5%

1,001-4,100 -32% -32%

Totals -32% -12%

≤100 -42% -42%

101-500 -47% -47%

501-1,000 -37% -37%

1,001-4,100 -43% -43%

Totals -43% -43%

≤100 -18% 17%

101-500 -23% 17%

501-1,000 -20% 4%

1,001-4,100 -37% -37%

Totals -19% 16%

Grand Total -23% 1%

Community Water Systems (CWSs) - SW

Community Water Systems (CWSs) - GW

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

Source: 

Exhibit 6.5. Percentages may not match results calculated directly from 

exhibit 6.5 due to rounding in exhibit 6.5. 

Notes:

1) Monitoring activates under RTCR begin in year 4 after rule 

promulgation. Therefore to represent the average annual acute violations 

occurring over the 25-year modeled time period, the total number of 

violations is divided by 22 years where monitoring activities are conducted.

2) Negative changes indicate reductions in the number of acute violations 

under either option in comparison to the 1989 TCR; positive changes 

indicate increases in acute violations. As described further in Section 6.4, 

a net increase in acute violations is caused by increased diagnostic power 

from increased sampling. 

Systems serving >4,100 were omitted from this table because there were 

no changes predicted in the number of violations to be incurred.

Transient Noncommunity Water Systems (TNCWSs) - SW

Transient Noncommunity Water Systems (TNCWSs) - GW
Economic Analysis for the Final RTCR 6-27 September 2012 

6.3.1.3 Overall Assessment of Predictive Analysis Results 

For PWSs serving ≤4,100 people, EPA expects risk to decrease under the RTCR and 

Alternative option as compared to the 1989 TCR. As shown by the year by year detail of the 

output provided in Appendix A of this EA and summarized in Exhibits 5.16–5.21, risk is further 

reduced for PWSs under the Alternative option relative to baseline (the 1989 TCR) for the first 5 

years after the effective date as compared to the RTCR relative to baseline. This additional 

reduction in risk under the Alternative option is driven by the increase in additional sampling 

that would occur while all systems were still on monthly sampling. Over time, some of these 

systems could qualify to move from monthly to quarterly under either the RTCR or the 

Alternative option, or from quarterly to annual sampling under the RTCR. Unlike the RTCR, no 

systems under the Alternative option would be able to sample annually. However, additional 

costs are incurred under the Alternative option for this increased monitoring, especially for the 

systems most impacted by the RTCR (TNCWSs serving ≤500 people). Chapter 7 presents the 

full discussion of costs associated with implementation of the regulatory options considered. 

When considering the period beginning in Year 9 after RTCR promulgation through the 

end of the period of analysis (model year 11 in Exhibits 5.16–5.21), the RTCR and Alternative 

option generally have similar estimates of occurrence. Year 9 after RTCR promulgation 

represents the first year of the steady state for monitoring regimens, when all PWSs that qualified 

for reduced monitoring are following their new regimens. However, for some categories and 

sizes of PWSs the RTCR actually has a lower rate of occurrence than the Alternative option. 

This may occur because states under the RTCR may have more resources available to perform 

the annual site visits at more PWSs based on states needing fewer resources for activities related 

to monitoring (tracking, compliance) than under the Alternative option. Appendix B includes 

graphs of predicted occurrence for each of the size and PWS categories considered in this 

analysis. 

EPA does not expect changes in risk for the PWSs serving >4,100 people under the 

RTCR to be as significant as they are for the systems serving ≤4,100 people. Systems serving 

>4,100 people are starting from a smaller baseline level of occurrence than systems serving 

≤4,100 people, and have a correspondingly lower level of triggered assessment and correction 

action activity. This suggests that such small percentage increases in these activities will result in 

relatively less change in risk, although the expected change is still a reduction in risk. 

Additionally, monitoring requirements for PWSs serving >4,100 people would remain 

essentially unchanged under either the RTCR or the Alternative option as compared to the 1989 

TCR. Thus the observed overall net increase in benefits (and costs) for PWSs serving >4,100 

people is driven by the requirements to conduct assessments and to correct any sanitary defects 

that are found. The increase of 10% from baseline in effective corrective actions implemented 

applies to systems serving >4,100 people just as it does to systems serving ≤4,100 people; 

however, as shown in Chapter 4 (Exhibit 4.10), the systems serving >4,100 people have a much 

smaller level of violations than systems serving ≤4,100 people, based on reasons discussed in 

Chapter 5 (Section 5.4). Therefore, increases in corrective actions will be less evident in absolute 

(not percentage) terms. 
Economic Analysis for the Final RTCR 6-28 September 2012 

6.4 Uncertainty and Sensitivity Analyses 

Key sources of uncertainty in the estimates provided in this EA include the data used to 

develop baseline estimates and the assumptions made regarding model input variables, as 

described in Chapters 4 and 5 of this EA, respectively. The quality and representativeness of the 

data used in this EA are discussed in Section 4.2, while uncertainty in model input variables is 

discussed in Section 5.3.3.1. A summary of assumptions made in developing the baseline and 

input parameters to the predictive model that contribute uncertainty to the analysis are included 

in Chapters 4 and 5 (Exhibits 4.13 and 5.22a–b). By definition, those uncertainty factors that are 

incorporated into the baseline will have a similar effect on the 1989 TCR, the RTCR and 

Alternative option; therefore, EPA believes that they will not significantly affect the net results 

of the EA. These assumptions are shown in Ex. 5.22a, and include the estimates representing 

GWR effects. Although EPA believes its GWR efficacy estimates are conservative, the estimates 

are applied in similar fashion to the baseline (1989 TCR) and RTCR and Alternative option; 

therefore, any bias that could be introduced is essentially canceled out in the net analysis. By 

contrast, the assumptions listed in Ex. 5.22b include those assumptions that will affect only the 

RTCR and Alternative option, such as the assumed increase in the number of effective corrective 

actions implemented as compared to the 1989 TCR. These types of assumptions are not canceled 

out in the net analysis, and are expected to have some effect on net results. Therefore, EPA has 

identified the key drivers of the analysis among this type of assumption and performed a 

sensitivity analysis on their values (Chapter 5, Section 5.3.3.1). 

This discussion focuses on the provisions of the RTCR and Alternative option for 

conducting corrective actions based on the results of Level 1 and Level 2 assessments performed, 

and the reductions in repeat samples following TC+ samples and in the additional routine 

samples required in the month following a TC+. The analyses performed and presented here are 

intended to provide insight into the overall impact of these two changes in rule provisions under 

the RTCR, each of which moves risk (as defined in this EA) in opposite directions. Unlike the 

uncertainty analysis presented in Chapter 5 (Occurrence and Predictive Model), this analysis 

does not consider variations on the assumptions related to corrective actions, but instead tests the 

relative impact of changes in the sampling regimen given the assumptions for corrective actions 

applied in the primary analysis of this EA (and summarized in Section 5.3). 

The primary benefit of the RTCR is a potential reduction in exposure to microbial 

contaminants from drinking water provided by PWSs. Two features of the RTCR are expected to 

influence the exposure reduction. 

The first feature is the requirement to perform corrective actions based on the results of 

the Level 1 and Level 2 assessments performed in response to their individual triggers. 

Implementation of additional corrective actions beyond the level currently implemented under 

the 1989 TCR will reduce exposure to microbial contamination both by addressing the 

immediate problem identified by the Level 1 or Level 2 assessment and by preventing some 

additional future exposures to fecal contamination. 

The second feature, which primarily affects the smaller systems, is the reduction in the 

numbers of additional routine and repeat samples that systems are required to take whenever 

routine samples are found to be TC+. This reduction in sampling may contribute to increased 
Economic Analysis for the Final RTCR 6-29 September 2012 

exposure and risk because fewer samples provide fewer opportunities to identify and address TC 

and E. coli exposures. 

The analyses that were performed used the predictive model with the occurrence input 

parameters for the nondisinfecting GW TNCWS serving <101 people. This set of systems was 

chosen because: 1) it contains the largest number of systems of the 27 occurrence sets (46,642 

systems in this set); 2) it is subject to all of the changes in sampling requirements; and 3) it has 

the highest routine TC hit rate so that effects on this set of systems are likely to be more 

pronounced (and therefore more clearly observable) than other sets. The analysis was carried out 

by running simulations of 10,000 systems each for monthly, quarterly, or annual monitoring 

schedules. 

There were five sampling and corrective action “regimens” considered in the model. As 

shown in Exhibit 6.7, Regimens 1 through 3 assume a routine sampling regimen equivalent to 

the 1989 TCR (i.e., 1 regular routine sample and a minimum of five routine samples in the month 

following a TC+). Regimen 1 is the only one of the five regimens that assumes there are no 

corrective actions (in addition to those already conducted under the 1989 TCR); Regimens 2 

through 5 all assume corrective actions are conducted in accordance with requirements under the 

RTCR. Regimens 3 through 5 decrease the repeat samples from four to three. Regimen 4 also 

decreases the minimum number of routine samples in the month following a TC+ from five to 

three; Regimen 5 uses the sampling requirements of the RTCR where systems doing monthly 

sampling need only take their one regular routine sample in a month following a TC+, while for 

those that monitor quarterly and annually, the requirement remains for a minimum of three 

additional routine samples in the month following a TC+. 

In this analysis, Regimen 1 describes the 1989 TCR and Regimen 5 describes the RTCR. 

Going from Regimen 1 to Regimen 2, where corrective actions are brought in without any 

change in sampling, provides key insights to the benefits (reduction in exposure) derived from 

the corrective action aspect of the RTCR. Going from Regimen 2 through Regimen 5 provides 

some insight into how much of those corrective action benefits might be foregone because of the 

small reductions in the number of TC samples required. 

The metric used for comparing the relative impacts of these five regimens was the 

number of acute violations based on EC+ assays (referred to as “acutes” throughout this section)

because this was considered to be the most relevant measure of the potential microbial health 

risk-based benefits of the RTCR. The numbers presented are the average annual numbers of 

acute violations. 

It is important to note that in order to isolate the effects of the RTCR corrective actions 

and sampling changes, this analysis excluded any effect of the GWR. To further understand the 

effects of sampling regimen, this analysis also presents the results separately for monthly, 

quarterly, and annual sampling since one of the changes in the RTCR applies only to those on 

monthly sampling. Exhibit 6.7 provides a summary of the results of this analysis. 
Economic Analysis for the Final RTCR 6-30 September 2012 

Exhibit 6.7 Relative Impacts Analysis for TNCWS Serving <101 People 

for the Range of Corrective Action and Sampling Regimens Predicted 

M Q A M Q A M Q A M Q A M Q A

1 5 5 5 4 No 168,252 60,980 15,317 279 106 25

2 5 5 5 4 Yes 160,394 59,693 15,103 198 92 26 80 14 -1 0 0 0

3 5 5 5 3 Yes 156,779 57,851 14,894 172 79 25 70 12 -1 37 14 2

4 3 3 3 3 Yes 151,500 189 77 13

5 1 3 3 3 Yes 146,129 175 71 32

Ratios of Prevented to Found: 0.41 0.15 -0.05

11 5

Regimen

Minimum Samples in 

Month

Following a TC+ Repeat 

Samples

L1 & L2 

CAs?

Average Total

TC Samples per Year

Average Acutes Per Year

Found

Key: (CA) = correction action; L1 and L2 = Level 1 and Level 2; M = monthly; Q = quarterly; and A = annual.

Definitions: Acutes “found” are acute violations the model predicts will be identified; acutes “prevented” are those avoided by implementation of CAs; acutes “missed” are those found under the 

sampling regimen of the 1989 TCR option (Regimen 1) that were not found under the reduced sampling of Regimens 3, 4, and 5 (calculated by subtracting acutes found under Regimens 3, 4, 

and 5 from those found under Regimen 1).

Notes: 

Results shown are averages based on simulations of 10,000 systems each for monthly, quarterly, and annual monitoring using occurrence inputs for nondisinfecting GW TNCWS serving <101 

people.

Assumptions for L1 and L2 CA efficacy and resulting duration of reduced occurrence are those used in the primary analysis.

For the purpose of isolating the relative impacts of changes in monitoring regimens and implementation of L1 and L2 CAs, no GWR effects (including GWR corrective actions) are modeled in 

these runs.

Ratios of acutes “prevented” to those “found” are based on Regimen 2 results, which reflect the 1989 TCR option sampling regimen but includes implementation of L1 and L2 CAs.

Average Acutes Per Year

Prevented

Average Acutes Per Year

Missed

55,411 14,031 82 21 13 -1

Regimen 1, representing the 1989 TCR, provides a baseline against which the other 

regimens can be compared. Although arguably more acute violations could be found if more 

routine and repeat samples were taken, the numbers of acute violations shown here as “found” 

(monthly = 279, quarterly = 106, and annual = 25) represent the maximum number that can be 

found given the amount of sampling done. This finding is based on analysis using 10,000 

simulated systems each for monthly, quarterly, and annual; the sampling scheme under the 1989 

TCR; and no additional corrective actions being performed. 

Regimen 2 uses the exact same sampling scheme as Regimen 1, but includes the 

performance of Level 1 and Level 2 corrective actions consistent with the RTCR. Here there is a 

reduction observed in the number of acutes found for monthly and quarterly sampling although 

not for annual sampling. Since there is no change in the sampling requirements, differences (and 

similarities) between Regimen 1 and Regimen 2 numbers are due to: a) the implementation of 

corrective actions under Regimen 2; and b) and random variation that is endemic to the Monte 

Carlo simulation. 

For monthly sampling, which requires a large number of TC samples per year, Monte 

Carlo variation is relatively small with respect to the effect of the parameter adjustments. 

Approximately 80 acute violations occur under monthly sampling for Regimen 1 (279 acutes) 

that do not occur under Regimen 2 (198 acutes) as the result of corrective actions. Quarterly and 

annual sampling regimens require far fewer TC samples per year, and therefore the Monte Carlo 

variation may obscure the salient data trends in those model results. For instance, the increase in 

the number of acutes under annual sampling under Regimen 1 from 25 to 26 under Regimen 2, 

which is not consistent with the trend seen in the larger sample size in the simulation of monthly 

systems, is likely to be reflective of stochastic noise from the Monte Carlo simulation performed 

rather than of the impact of corrective actions. For this reason most of the discussion that follows 

on the trends across these regimens focuses on the monthly sampling results. 

Regimen 3 reflects the reduction in repeat sampling requirements of four to three

following a TC+. As would be expected, this also results in a small reduction in the number of 

acutes found. For example, in the monthly sampling group this falls from 198 to 172. Using an 
Economic Analysis for the Final RTCR 6-31 September 2012 

assumption that the ratio of acutes prevented to acutes found in Regimen 2 apply to the other 

regimens as well, then results for the monthly sampling group (where 80/198 = 0.41 for Regimen 

2) indicate that 70 acutes are still prevented under Regimen 3. The sum of those found under 

Regimen 3 (172) and those prevented under Regimen 3 (70) for the group of systems on monthly 

sampling is 242. This implies, then, that as a result of the reduction in repeat sampling from four 

to three, a total of 37 acutes are missed under Regimen 3. 279 acutes are found under the 1989 

TCR sampling regimen (Regimen 1); therefore, the number of acutes missed is calculated as 279 

– (172+70) = 37. That is, these 37 acute violations are neither found nor prevented under 

Regimen 3, but are assumed to occur unobserved. 

Regimen 4 reduces the number of routines in a month following a TC+ from five to three, 

but retains the three repeats and the corrective action requirements. The number of acutes now 

“missed” changes to 13, 11, and 5 respectively for those on monthly, quarterly, and annual

sampling. 

Regimen 5, which represents the RTCR, excludes any additional routine samples in the 

month following a TC+ for those on monthly sampling. Here the number of “missed” acutes for 

those on monthly increases from 13 to 32. There are no changes for those on quarterly or annual 

sampling relative to Regimen 4 since systems sampling quarterly and annually are treated 

identically in both scenarios. 

In addition to displaying the changes in the number of annual average acutes for these 

five regimens, Exhibit 6.7 also shows the average annual number of TC samples (regular routine, 

additional routines and repeat samples) taken. The number of samples declines considerably 

across the regimens due both to the reduction in actual sampling requirements and to reduced 

number of additional routines and repeats that need to be taken because of the prevention of TC 

occurrence by the corrective actions taken. 

This analysis points first and foremost to the highly positive public health benefits of 

including the corrective actions as part of the RTCR (based on the modest assumptions regarding 

their effectiveness used in the occurrence analysis detail in Chapter 5 of this EA). This is seen 

not only in the number of acutes that are found for which corrective actions may be performed, 

but also—and perhaps more importantly—in the large number of additional acutes that are 

prevented from occurring again in those systems as a result of the corrective actions.

While some of these potential benefits are “missed” as a result of the reductions in 

additional routine and repeat sampling requirements, these numbers (shown in Exhibit 6.7) seem 

small when compared to the numbers found and prevented. This is particularly important when 

considering the potential cost savings from reducing the number of TC samples that are taken, as 

discussed in Chapter 9 (Net Benefits) of this EA. 

The group of 61,539 TNCWSs serving ≤100 currently has, and will continue to have, a 

vast majority of systems on either quarterly or annual sampling in the steady state of the analysis 

period, beginning in approximately Year 9 after RTCR promulgation. Since quarterly and annual 

estimates of acutes are less stable, predictions for this specific subset of systems are less reliable. 

Nonetheless, since approximately 40% of systems affected by the RTCR are on monthly 

sampling, the trends in the monthly numbers cited above should be indicative of trends for other 
Economic Analysis for the Final RTCR 6-32 September 2012 

types and sizes of systems included in this model (those serving ≤4,100 people). That is, relative 

to the 1989 TCR, the inclusion of the Level 1 and Level 2 corrective actions will always result in 

more benefits accruing from corrective actions being performed and acute violations being 

avoided than the relatively small reductions in sample numbers will result in “missing” acute 

violations. 

Because all of the other system types have lower overall TC and E. coli hit rates than the 

nondisinfecting GW TNCWS serving <101 people, on a per system basis their missed acute 

violations would be fewer than those estimated for the set of systems addressed in this analysis. 

Furthermore, for the systems serving 1,001 to 4,100 people where the RTCR change in the 

minimum number of samples to be taken in the month following a TC+ is smaller, the number of 

missed acute violations would be less than that seen in this analysis for the systems serving <101 

people. For example, for systems serving 3,301 to 4,100 (which are all on monthly sampling), 

the minimum number of next month samples is reduced from five to four compared with a 

reduction from five to one for the systems serving fewer than 1,001 people that perform monthly 

sampling. Thus this analysis presents an estimate that is near the higher end of the range for 

various system types in expected missed acute violations due to reduced sampling requirements 

under the RTCR. In spite of this conservative estimate, the effect of the RTCR requirements for 

corrective actions more than balances this effect with a larger change in risk in the opposite 

(reducing) direction, as shown by the relatively large number of prevented to missed acute 

violations. 

6.5 Other Potential Benefits 

A number of other benefits may accrue to PWSs and their populations served that are not 

included in the qualitative relative risk comparison or reductions in occurrence discussed in 

Sections 6.1–6.4 (above), they are described in the following sections. 

6.5.1 Increased System Knowledge 

By requiring additional assessments focused on isolating and identifying system 

problems in response to TC+ or EC+ samples, the RTCR will increase the likelihood that PWS 

operators, in particular those of systems triggered to conduct assessments, will develop further 

general understanding of system operations and potential issues. This heightened familiarity with 

the system may increase preventive maintenance, or may increase the efficiency with which 

future problems are identified, decreasing risk to the PWS population served in both cases. 

Delaying system component replacement costs or avoiding an increase in treatment costs may 

also result from this increased knowledge and result in cost savings for some communities. 

6.5.2 Accelerated Infrastructure Repair/Replacement 

As described in 6.5.1 (above), the increased familiarity of operators with their systems 

may encourage an increase in preventive maintenance, preempting some potential contamination 

issues and decreasing risk for the PWS population served. Some systems may see additional nonquantified benefits associated with the acceleration of their capital replacement fund investments 

in response to early identification of impending problems with large capital components. 

Although such capital investment would have occurred anyway, earlier investment may ensure 
Economic Analysis for the Final RTCR 6-33 September 2012 

that problems are addressed in a preventive manner and may preclude some decrease in 

protection that may have occurred otherwise. At the very least, the increased operator awareness 

should reduce the occurrence of unplanned capital expenditures in any given year. 

6.5.3 Reduction in Averting Behavior 

As the risk of contamination is reduced in PWSs over time following RTCR 

promulgation, EPA expects that the public will eventually become aware of increased quality, 

and consistency of quality, of their water. This may lead to PWS customers becoming 

increasingly comfortable with drinking tap water and cause them to exercise less averting 

behavior (e.g., drinking bottled water or using point of use filtration devices). Such averting 

behaviors are costly relative to consuming tap water. 

6.5.4 Reduction of Co-Occurring and Other Contaminants 

In addition to the specific E. coli endpoint targeted by the RTCR, there are many 

potentially co-occurring and emerging pathogens (such as viruses, parasitic protozoa and/or other 

bacteria) that may be avoided as part of any avoided contamination event. To the extent that E. 

coli co-occurs with pathogens sufficiently in abundance to result in health effects, the RTCR 

offers the potential for additional morbidity and mortality prevention. 

Potential benefits from the RTCR include avoidance of a full range of health effects, 

including acute and chronic illness, endemic and epidemic disease, associated outbreaks and 

death that may occur from the consumption of fecally contaminated drinking water. Also, since 

fecal contamination may contain waterborne pathogens including bacteria, viruses, and parasitic 

protozoa, in general, a reduction in fecal contamination should also reduce the risk from these 

other contaminants. 

Systems may choose corrective actions that also address other drinking water 

contaminants. For example, correcting for a pathway of potential contamination into the 

distribution system can mitigate a variety of potential contaminants. Due to a lack of 

contamination co-occurrence data that quantify the effect that treatment corrective action may 

have on contamination entering through distribution system pathways, EPA has not quantified 

such potential benefits. 

6.5.5 Reduction in Outbreak Risk and Response Costs 

Besides reducing the endemic risk of illnesses from waterborne pathogens, the RTCR 

would reduce the likelihood of major outbreaks from occurring. These avoided illnesses and 

other costs are not estimated or included in the RTCR analyses and would be difficult to 

quantify. The economic value of reducing the risk of outbreaks could be quite high when the 

magnitude of potential costs is considered. The Agency was unable to quantify or monetize the 

cost associated with acute and chronic illnesses or death acquired from consuming water 

contaminated with waterborne pathogens because cases avoided could not be calculated, as 

described in Section 6.2. Examples of potential illnesses associated with ingestion of waterborne 

pathogens and their potential costs are described in Chapter 2 of this EA. 
Economic Analysis for the Final RTCR 6-34 September 2012 

Other types of costs associated with outbreaks include spending by local, state, and 

national public health agencies; emergency corrective actions by utilities; and possible legal 

costs if liability is a factor. Affected water systems and local governments may incur costs 

through provisions of alternative water supplies and issuing customer water use warnings and 

health alerts. Commercial establishments (e.g., restaurants) and their customers may incur costs 

due to interrupted and lost service. Local businesses, institutions, and households may incur costs 

associated with undertaking averting and defensive actions. Thus, to the extent that the RTCR 

reduces the likelihood of waterborne disease outbreaks, avoided response costs are potentially 

numerous and significant. For example, an analysis of the economic impacts of a waterborne 

disease outbreak in Walkerton, Ontario (population 5,000) estimated the economic impact 

(excluding estimates of the value of a statistical life for seven deaths and intangible costs for 

illness-related suffering) to be over $45.9 million47 in 2007 Canadian dollars (approximately 42.8 

million 2007 U.S. dollars)48 (Livernois, 2002). Note that some of these costs were incurred by 

individuals and businesses in neighboring communities. The author believed that this was a 

conservative estimate.

 

47 Households and businesses in the town of Walkerton were unable to use municipal water for eight months 

following the contamination event. The response involved a massive effort at all levels of government in terms of 

public health response and investigation of the cause. The paper asserts that the impact of the crisis extended beyond 

Walkerton to nearby towns and the countryside, resulting in economic costs that the author expects were at a 

minimum equal to the costs presented in the paper (of which only the non-medical costs are included here). 

48 Updated from $43 million in Canadian dollars, $32 million U.S. dollars in 2000. Costs updated from 2000 dollars 

to 2007 dollars using the Canadian core CPI (= 95.71667 ÷ 109.8167 = 1.14731) and the 2007 exchange rate 

(1.0734 Canadian dollars /1.0 U.S. dollars). 
Economic Analysis for the Final RTCR 7-1 September 2012 

7 Cost Analysis 

7.1 Introduction 

This chapter presents estimates of the total national and household costs of the Revised 

Total Coliform Rule (RTCR). To estimate the national costs of the RTCR, the United States 

Environmental Protection Agency (EPA or Agency) calculated the net change in costs (i.e., 

incremental costs over the 1989 Total Coliform Rule (1989 TCR)) of rule components associated 

with state49 practices and system activities required under the revised rule. The remainder of this 

chapter provides detailed discussion of the methodology used and results from the cost analyses 

and is organized as follows: 

 Section 7.2 describes the cost model and general costing and compliance 

assumptions used to estimate national costs of the RTCR. 

 Section 7.3 describes the methodology of projecting costs over a 25-year period 

(discounted at 3 and 7 percent, respectively) according to the RTCR compliance 

schedule, estimating the present value of each cost, and annualizing each over a 25-

year period. 

 Section 7.4 describes the methodology for developing costs for all rule activities. 

 Section 7.5 presents household cost estimates. 

 Section 7.6 presents a discussion of non-quantified costs. 

 Section 7.7 presents a discussion of uncertainties in cost estimates. 

 Section 7.8 presents a comparison of cost estimates for all regulatory options.

7.2 General Cost Assumptions and Methodology 

The RTCR cost model builds on the baseline data, occurrence analysis, and benefits 

model results described in Chapters 4–6. Based on these analyses, the annual and cumulative 

numbers of public water systems (PWSs) that would be required to comply with each rule 

component of the RTCR over the 25-year compliance period are provided in Appendix A 

(Exhibits 6.2–6.4 provide a summary of this information). In general, the numbers of PWSs 

presented in Appendix A are multiplied by the unit cost assumptions described in this chapter to 

calculate total annual costs. 

There are also several general costing assumptions that are unique to the costing process 

and are used as inputs to the cost model. The derivation of these inputs is discussed in detail 

below. 

 

49 The term “state” in the context of this chapter refers to any state or other primacy agency that has oversight 

authority for drinking water programs. 
Economic Analysis for the Final RTCR 7-2 September 2012 

7.2.1 Labor Rates 

For costing purposes, EPA estimates the labor needs and hourly labor rates of PWSs and 

states. EPA recognizes that there may be significant variation in labor rates across all PWSs. 

However, for purposes of this economic analysis (EA), and to implement national policy, EPA 

uses national-level estimates from Labor Costs for National Drinking Water Rules (USEPA, 

2003a) (as used in the Ground Water Rule Economic Analysis (USEPA, 2006a)). For the RTCR 

cost analyses, these labor rates were inflated to 2007$ using the Employee Cost Index (ECI), and 

weighted based on the PWS size categories used in the RTCR EA. To account for the general 

composition of staff at PWSs of smaller sizes (e.g., PWSs serving 3,300 or fewer), EPA uses 

only the technical rate. For PWSs serving more than 3,300 people, EPA uses a ratio of 80 percent 

technical labor to 20 percent managerial labor to arrive at a labor cost, or weighted labor rate. 

The actual ratio between technical and managerial rates employed may vary by PWS and among 

the different compliance activities under the RTCR. However, for simplicity, the 80/20 ratio is 

used as a general assumption for costing purposes in this EA. A full description of the derivation 

of the labor rates used is provided in the Technology and Cost Document for the Final Revised 

Total Coliform Rule (USEPA, 2010d). The weighted labor rates ($2007) are shown in Exhibit 

7.1.

Exhibit 7.1 Labor Rates by PWS Size (2007$) 

PWS Size (population served) Weighted Labor Rate ($/hour)

< 100 $ 25.10 

101 - 500 $ 27.03 

501 - 1,000 $ 28.96 

1,001 - 4,100 $ 29.73 

4,101 - 33,000 $ 36.00 

33,001 - 96,000 $ 36.39 

96,001 - 500,000 $ 41.01 

500,001-1 Million $ 41.01 

> 1 Million $ 41.01 

Source: Final RTCR T&C Document

Note: Labor rates for each size category are assumed to be the same 

regardless of system type (CWS, NTNCWS, and TNCWS).

For states, the administrative and field engineer labor rates from the 2001 State Drinking 

Water Needs Analysis (ASDWA, 2001) are used in the RTCR EA (as used in the Ground Water 

Rule (GWR) EA (USEPA, 2006a)). These rates include a 60 percent overhead rate and were 

inflated to 2007$ using the ECI. EPA recognizes that there may be significant variation in labor 

rates across all states. The state labor rates in 2007$ are $39.22 for an administrative state 

employee and $43.58 for a state field engineer. EPA assumes that the state field engineer would 

conduct annual site visits,50 and the administrative state employee would work with PWSs on all 

remaining aspects of the RTCR. Because this separation between field engineer and 

 

50 Because of the high cost for an annual site visit by a state, for this analysis, EPA assumes that no states would 

choose to conduct annual site visits unless they already do so under the 1989 TCR. See section 7.4.4 for additional 

information. 
Economic Analysis for the Final RTCR 7-3 September 2012 

administrative employee is used, the 80/20 weighting ratio between technical and managerial 

rates is not used to develop state costs. 

7.2.2 TCR Monitoring Costs per Sample 

A cost per sample is associated with distribution system monitoring. For the purpose of 

this cost analysis, PWSs would perform total coliform (TC) monitoring, supplemented by E. coli 

analyses as required. EPA estimated the sample analysis cost for both in-house and commercial 

laboratory analysis. The weighted unit costs for monitoring provided in Exhibit 7.2 are based on 

the percentage of PWSs conducting in-house and commercial laboratory analysis based on 

conversations of the Total Coliform Rule Distribution System Advisory Committee (TCRDSAC) 

Technical Workgroup (TWG). For in-house sample analysis, the estimated burden includes 

sample collection and analysis and also accounts for operations and maintenance (O&M) costs 

such as equipment and maintenance. For commercial laboratory analysis, the estimated burden 

includes sample collection, shipping and delivery, and the laboratory analysis fee. These 

estimates reflect a national average; however, individual PWSs may realize collection burden

that is either less than or greater than this average depending on the locations of sampling points 

in a particular PWS. 

Rates may vary due to regional variations in laboratory fees, the number of samples 

processed (quantity discounts), and laboratory capacity. As shown in Exhibit 7.2, the cost per 

sample decreases as more samples are taken, and as PWSs take advantage of savings from bulk 

shipping. A full description of the derivation of the monitoring costs per sample is provided in 

the Technology and Cost Document for the Final Revised Total Coliform Rule (USEPA, 2010d). 

Exhibit 7.2 Monitoring Costs per Sample (2007$) 

1 2 3 4 > 5

< 100 $ 50.54 $ 42.64 $ 40.01 $ 38.69 $ 37.90 

101 - 500 $ 51.55 $ 43.63 $ 40.99 $ 39.67 $ 38.87 

501 - 1,000 $ 59.81 $ 51.86 $ 49.21 $ 47.88 $ 47.09 

1,001 - 4,100 $ 60.40 $ 52.45 $ 49.79 $ 48.47 $ 47.67 

4,101 - 33,000 $ 65.26 $ 57.23 $ 54.55 $ 53.21 $ 52.40 

33,001 - 96,000 $ 60.57 $ 56.55 $ 55.21 $ 54.54 $ 54.14 

96,001 - 500,000 $ 72.38 $ 71.57 $ 71.30 $ 71.17 $ 71.09 

500,001-1 Million $ 72.38 $ 71.57 $ 71.30 $ 71.17 $ 71.09 

> 1 Million $ 72.38 $ 71.57 $ 71.30 $ 71.17 $ 71.09 

PWS Size

(population served)

Numbers of Samples Taken and Delivered at the Same Time

Note: Per sample monitoring costs for each size category are assumed to be the same regardless 

of PWS type (CWS, NTNCWS, and TNCWS).

Source: Final RTCR T&C Document

7.2.3 Technology Unit Costs and Compliance Forecasts 

EPA has assumed that PWSs may use a variety of existing best management practices 

(BMPs) and technologies to address distribution system deficiencies discovered during Level 1 
Economic Analysis for the Final RTCR 7-4 September 2012 

and Level 2 assessments. These BMPs and technologies include a combination of flushing 

programs, training of personnel to collect samples, replacing valves/pipes/hydrants/meters, 

installing new water mains, modifying operation of storage facilities, booster disinfection, 

physical security devices, etc. For a full list of technologies and BMPs that are anticipated to be 

used to meet rule requirements, see Appendix D. EPA estimated unit costs for these various 

components using equipment price lists and quotes, costs associated with BMPs from PWSs, 

engineering cost data sources (e.g., Means, 1998), consultations with the TWG supporting the 

TCRDSAC Federal Advisory Committee (FAC), and other relevant assumptions used in 

economic analyses performed for existing drinking water rules (e.g., GWR). Detailed 

explanations of the unit cost derivations for these BMPs and technologies are presented in the 

Technology and Cost Document for the Final Revised Total Coliform Rule (USEPA, 2010d).

Compliance forecasts (or technology selection forecasts) are estimates of which 

technologies PWSs undergoing corrective action would use. Section 7.4.6 provides details on 

compliance forecasts for PWSs performing corrective actions based on Level 1 and Level 2 

assessments. 

7.2.4 Cost Model 

National costs are estimated using a cost model specifically developed for the RTCR. The 

model builds on the occurrence model described in Chapter 5. Within the modeling structure, 

costs for PWSs serving >4,100 retail customers are analyzed differently from smaller PWSs to 

capture differing baseline structures and to account for differences in available occurrence data 

as described in Chapter 4. 

PWS costs are estimated for different PWS types and size categories (nine size categories 

are used based on population served, consistent with the Technology and Cost Document for the 

Final Revised Total Coliform Rule (USEPA, 2010d)). PWS cost analyses include estimates to 

implement the rule; to revise sample siting plans; to conduct routine monitoring, additional 

routine monitoring, and repeat monitoring; to perform Level 1 and Level 2 assessments and 

implement corrective actions; and to provide public notification (PN). State cost analyses include 

estimates of the labor burdens that states would face, including staff training on RTCR 

requirements and conducting annual administration, reviewing monitoring reports, reviewing 

assessments, reviewing and approving corrective action plans, and recordkeeping. Section 7.4 

provides detailed discussion on the underlying cost-buildup for each rule component analyzed 

within the cost model. 

7.2.5 Modeled Variability and Uncertainty in National Costs 

As noted throughout this EA, there is variability among many of the input parameters to 

the RTCR cost model and several rule compliance assumptions based on PWS size and type 

(e.g., population served, labor rates, TC hit rates, and occurrence distributions are different for 

different sizes and types of PWSs). However, there is insufficient information to fully 

characterize the distribution of variability (i.e., calculating confidence bounds) within each of 

these PWS size and type classifications on a national scale; therefore, EPA uses mean values for 

these input parameters. 
Economic Analysis for the Final RTCR 7-5 September 2012 

EPA also recognizes that there is uncertainty in the national cost estimates, much of 

which has the same impact on the modeled results of both the 1989 TCR and RTCR (e.g., 

baseline assumptions and effects of GWR implementation). Because the EA analyses focus on 

net changes between the 1989 TCR and the RTCR, these common sources of uncertainty cancel 

each other out in the net change analyses. For assumptions that are major drivers of the analysis 

and differ between the 1989 TCR and RTCR (e.g., corrective action compliance forecast), EPA 

has evaluated uncertainty and performed sensitivity analyses to qualitatively and quantitatively 

characterize the potential impacts of alternative input parameters. Chapter 5 discusses 

uncertainty and presents sensitivity analyses pertaining to the predictive occurrence model 

results, which also impact the cost calculations. Section 7.7 discusses uncertainty and provides 

sensitivity analysis results as they specifically pertain to the cost analyses. 

7.3 Projecting and Discounting National Costs 

Costs must be expressed in common units so they can be added together to calculate total 

annual costs and compared to benefits. For the RTCR, the performance of activities varies over 

time in response to regulatory requirements and monitoring results. To compare the values of 

performing these activities, the year or years in which all costs are expended must be determined 

and the costs must be calculated as a net present value. For the purposes of this EA, one-time and 

yearly costs were projected over a 25-year time period to allow comparison with other drinking 

water regulations using the same analysis period. The net present values of costs are calculated 

using discount rates of 3 and 7 percent based on EPA policy and guidance from the Office of 

Information and Regulatory Affairs of the Office of Management and Budget (OMB).51 A 

summary of the steps used in making adjustments to the national-level costs presented in this EA 

is as follows: 

 Estimate all costs (noncorrective action, corrective action, and state) over a 25-year 

time horizon based on the rule implementation schedule. 

 Calculate total net present value costs using 3 and 7 percent discount rates. 

 Annualize the costs over 25 years using the same discount rates. 

Appendix C presents step-by-step results for the projection and discounting of costs to 

show how yearly costs for each rule component are accounted for by the cost model for 

community water systems (CWSs), nontransient noncommunity water systems (NTNCWSs), 

transient noncommunity water systems (TNCWSs), and states. Exhibits C.1 through C.9 show 

the nominal costs projected over the rule schedule and the present value of each cost calculated 

to the expected year of rule implementation for the 1989 TCR. Exhibits C.10 through C.45 show 

the results for the RTCR and the Alternative option. 

 

51 The choice of an appropriate discount rate is a complex and controversial issue among economists and policy 

makers. Therefore, the Agency compares streams of future national level costs and benefits using two alternative 

discount rates, 3 and 7 percent. The underlying logic for each discount rate can be found in Guidelines for Preparing 

Economic Analyses (USEPA, 2000). 
Economic Analysis for the Final RTCR 7-6 September 2012 

7.4 Derivation of Costs for PWSs and States 

This section presents the methodology and unit costs used to derive national costs for 

PWSs and states to perform 1989 TCR- and RTCR-related activities. Chapter 3 contains detailed 

summaries of the activities under the 1989 TCR, RTCR, and Alternative option. The following 

subsections provide a brief summary of each activity and the assumptions used to estimate the 

burden and costs attributable to both PWSs and states for: 

7.4.1 Rule Implementation and Annual Administration 

7.4.2 Revise Sample Siting Plan 

7.4.3 Monitoring 

7.4.4 Annual Site Visits 

7.4.5 Assessments 

7.4.6 Corrective Actions 

7.4.7 Public Notification 

This chapter uses information from the baseline analysis in Chapter 4 as a starting point 

for analysis of PWSs subject to each rule requirement. Additional baseline information and 

detailed intermediate model outputs are provided in Appendix A. There are also 57 states and 

primacy agencies that would incur costs as a result of the rule. 

7.4.1 Rule Implementation and Annual Administration 

PWSs 

Under the RTCR and Alternative option, all PWSs subject to the rule would incur onetime costs that include time for staff to read the rule and become familiar with its provisions and 

to train employees on rule requirements. No additional implementation burden or costs are 

incurred by PWSs to implement the 1989 TCR, as these PWSs have already performed 

implementation and are continuing to perform annual administration activities under the 1989 

TCR. Under the RTCR and Alternative option, all PWSs subject to the RTCR would perform 

additional or transitional implementation activities. The labor rates presented in Section 7.2.1 are 

used along with estimates of labor hours to generate estimated implementation costs for all 

PWSs. Based on previous experience with rule implementation and consistent with estimates 

used in the GWR EA, EPA estimates that PWSs would require a total of 4 hours to read and 

understand the rule, and a total of 8 hours to plan and mobilize (i.e., assign appropriate personnel 

and resources to carry out rule activities). 
Economic Analysis for the Final RTCR 7-7 September 2012 

Exhibit 7.3 Net Change in PWS Unit Burden and Cost Estimates for Rule 

Implementation (2007$) 

A B C D=A*(B+C)

Community Water Systems (CWSs)

≤100 $ 25.10 4.0 8.0 301.20 $ 

101-500 $ 27.03 4.0 8.0 324.36 $ 

501-1,000 $ 28.96 4.0 8.0 347.52 $ 

1,001-4,100 $ 29.73 4.0 8.0 356.76 $ 

4,101-33,000 $ 36.00 4.0 8.0 432.00 $ 

33,001-96,000 $ 36.39 4.0 8.0 436.68 $ 

96,001-500,000 $ 41.01 4.0 8.0 492.12 $ 

500,001-1 Million $ 41.01 4.0 8.0 492.12 $ 

> 1 Million $ 41.01 4.0 8.0 492.12 $ 

Nontransient Noncommunity Water Systems (NTNCWSs)

≤100 $ 25.10 4.0 8.0 301.20 $ 

101-500 $ 27.03 4.0 8.0 324.36 $ 

501-1,000 $ 28.96 4.0 8.0 347.52 $ 

1,001-4,100 $ 29.73 4.0 8.0 356.76 $ 

4,101-33,000 $ 36.00 4.0 8.0 432.00 $ 

33,001-96,000 $ 36.39 4.0 8.0 436.68 $ 

96,001-500,000 $ 41.01 4.0 8.0 492.12 $ 

500,001-1 Million $ 41.01 4.0 8.0 492.12 $ 

> 1 Million $ 41.01 4.0 8.0 492.12 $ 

Transient Noncommunity Water Systems (TNCWSs)

≤100 $ 25.10 4.0 8.0 301.20 $ 

101-500 $ 27.03 4.0 8.0 324.36 $ 

501-1,000 $ 28.96 4.0 8.0 347.52 $ 

1,001-4,100 $ 29.73 4.0 8.0 356.76 $ 

4,101-33,000 $ 36.00 4.0 8.0 432.00 $ 

33,001-96,000 $ 36.39 4.0 8.0 436.68 $ 

96,001-500,000 $ 41.01 4.0 8.0 492.12 $ 

500,001-1 Million $ 41.01 4.0 8.0 492.12 $ 

> 1 Million $ 41.01 4.0 8.0 492.12 $ 

Notes: 

Sources:

(A) Labor rates for PWSs from Exhibit 7.1.

(B), (C) EPA estimates based on best professional judgment.

Unit Cost

PWS burden and cost estimates for implementation activities are assumed to be identical under the 

RTCR and Alternative Option.

PWS Size

(Population

Served)

Labor Cost 

(per hour)

Read and 

Understand 

Rule 

(hours/system)

Planning and 

Mobilization 

(hours/system)
Economic Analysis for the Final RTCR 7-8 September 2012 

States 

States would incur administrative costs to implement the RTCR. These implementation 

costs are not directly required by specific provisions of the RTCR but are necessary for states to 

ensure that the provisions of the RTCR are properly carried out. States would need to allocate 

time for their staff to establish and maintain the programs necessary to comply with the RTCR, 

including developing and adopting state regulations and modifying data management systems to 

track new required PWS reports to the states. As a one-time burden covered under the 520 hours 

allocated to modifying data management systems, each state would modify their data 

management system to be able to track the changes in monitoring regimes. Note, on average no 

on-going annual cost is assumed for modifying data management because the tracking system 

would already be in place and oversight would be accounted under state review of sampling 

results, assessments, etc. Time requirements for a variety of state agency activities and responses 

are estimated in this EA. Exhibit 7.4 lists the activities required to revise the program following 

promulgation of the RTCR along with their respective costs and burden. Because time 

requirements for implementation and annual administration activities vary among state agencies, 

EPA recognizes that the burden and cost estimates presented in Exhibit 7.4 may be an over- or 

underestimate for some states.

Exhibit 7.4 Net Change in State Unit Burden and Cost Estimates for Rule 

Implementation (2007$) 

Labor Cost

(per hour) Hours FTEs Cost

A B C=B/2,080 D=A*B

$ 39.22 1 5 0.01 $ 588

$ 39.22 260 0.13 $ 10,197

$ 39.22 - - -$ 

$ 39.22 520 0.25 $ 20,393

$ 39.22 520 0.25 $ 20,393

$ 39.22 130 0.06 $ 5,098

Per State Total 1,445 $ 56,670

National Totals (57 States/Primacy Agencies) 82,365 $ 3,230,201

Staff Training

Read and Understand Rule

Compliance Activity

Regulation Adoption and Program Development

Initial Laboratory Certification

Modify Data Management Systems

PWS Training and Technical Assistance

Notes:

Detail may not add due to independent rounding.

State burden and cost estimates for Implementation activities are assumed to be identical under the RTCR and Alternative 

Option.

Sources:

(A) Labor rate for state employee from Section 7.2.1.

(B) Labor hours for start-up activities are based on GWR estimates. Because the RTCR is a revision of the 1989 TCR, one 

fourth of the State unit start up burden from GWR is used in the RTCR. 

(C) Full-time equivalent (FTE) assumes individual w orking 40 hours per w eek, 52 w eeks per year.

In addition to these one-time costs, states would use resources to continue administrative 

activities. On an annual basis, states must coordinate with their particular EPA regional office to 

be certain that the state’s program is consistent with federal requirements. States would also 

continue to train state and PWS staffs, maintain laboratories’ certifications, and report PWS 

compliance information to the Safe Drinking Water Information System (SDWIS). However, 
Economic Analysis for the Final RTCR 7-9 September 2012 

based on discussions with stakeholders, once the initial implementation activities are complete, 

the annual burden (on average) for general administrative tasks for the RTCR would not be any 

higher than the burden incurred under the 1989 TCR requirements. In some cases, the general 

administrative burden for the 1989 TCR may actually decrease as PWSs experience better 

performance, and thus require less state interaction, under the RTCR. Therefore, no continuing 

annual administrative costs are estimated for the EA. 

States would also spend time responding to specific requirements under the RTCR (i.e., 

review assessment reports, consult with PWSs, etc.). In these cases, the state costs are estimated 

under the costing for that particular rule requirement. 

Implementation Net Cost Summary 

Because EPA does not anticipate early implementation of the RTCR, EPA expects that 

implementation activities would take place in years 1 through 3 of the 25-year compliance period 

before PWSs begin monitoring activities. Annualized cost estimates for PWSs and states to 

perform implementation activities are estimated by multiplying the number of PWSs or states 

required to comply with the RTCR (i.e., all PWSs) by the unit costs presented in Exhibits 7.3 and 

7.4. Total and net change in annualized present value cost estimates for PWSs and states to 

perform implementation activities under the 1989 TCR, RTCR, and Alternative option are 

presented in Exhibit 7.5. 

Exhibit 7.5 Annualized Cost Estimates for Rule Implementation ($Millions, 2007$) 

PWSs State Total PWSs State Total

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total $ 2.77 $ 0.18 $ 2.95 $ 4.00 $ 0.26 $ 4.26

RTCR - Net Change $ 2.77 $ 0.18 $ 2.95 $ 4.00 $ 0.26 $ 4.26

Alternative Option - Total $ 2.77 $ 0.18 $ 2.95 $ 4.00 $ 0.26 $ 4.26

Alternative Option - Net Change $ 2.77 $ 0.18 $ 2.95 $ 4.00 $ 0.26 $ 4.26

Notes: 

1) Detail may not add due to independent rounding.

2) PWS and state burden and cost estimates for implementation activities are assumed to be identical under the RTCR and Alternative Option.

Source: Final RTCR Cost Model.

3% Discount Rate 7% Discount Rate

7.4.2 Revise Sample Siting Plan 

PWSs 

Under the RTCR and Alternative option, all PWSs subject to the RTCR would incur onetime costs to revise existing sample siting plans to identify sampling locations and collection 

schedules that are representative of water throughout the distribution system. System sample 

siting plans must include routine and repeat sample sites and any sampling points necessary to 

meet GWR requirements. Under the TCR, no additional burden or costs are expected to be 

incurred by PWSs to revise sample siting plans, as these PWSs are already collecting TC

samples in accordance with a written sample siting plan. The labor rates presented in Section 

7.2.1 are used along with estimates of labor hours to generate sample siting plan costs for all 
Economic Analysis for the Final RTCR 7-10 September 2012 

PWSs. Based on previous experience, EPA estimates that PWSs would require 2–8 hours for 

revising their sample siting plan, depending on PWS size. Estimates of PWS unit costs to revise 

sample siting plans are presented in Exhibit 7.6. 

States 

Under the RTCR and Alternative option, states are expected to incur one-time costs to 

review sample siting plans and recommend any revisions to PWSs. Under the 1989 TCR, no 

additional burden or costs are incurred by states to review sample siting plans, as these PWSs’ 

sample siting plans have already been reviewed and approved. State costs are based on the 

number of PWSs submitting revised sample siting plans to PWSs each year. The state labor rate 

presented in Section 7.2.1, the number of PWSs in each PWS size category required to revise 

sample siting plans, and estimates of labor hours are used to generate sample siting plan costs 

incurred by states. Based on previous experience, EPA estimates that states would require 1–4 

hours to review revised sample siting plans and provide any necessary revisions to PWSs, 

depending on PWS size. Estimates of state unit costs to revise sample siting plans are presented 

in Exhibit 7.6. 
Economic Analysis for the Final RTCR 7-11 September 2012 

Exhibit 7.6 Net Change in PWS and State Burden and Cost Estimates to Revise 

Sample Siting Plans (2007$) 

A B C=A*B D E F=D*E

Community Water Systems (CWSs)

≤100 $ 25.10 2.0 $ 50.20 $ 39.22 1.0 $ 39.22

101-500 $ 27.03 2.0 $ 54.06 $ 39.22 1.0 $ 39.22

501-1,000 $ 28.96 4.0 $ 115.84 $ 39.22 2.0 $ 78.44

1,001-4,100 $ 29.73 4.0 $ 118.92 $ 39.22 2.0 $ 78.44

4,101-33,000 $ 36.00 6.0 $ 216.00 $ 39.22 3.0 $ 117.65

33,001-96,000 $ 36.39 8.0 $ 291.12 $ 39.22 4.0 $ 156.87

96,001-500,000 $ 41.01 8.0 $ 328.08 $ 39.22 4.0 $ 156.87

500,001-1 Million $ 41.01 8.0 $ 328.08 $ 39.22 4.0 $ 156.87

> 1 Million $ 41.01 8.0 $ 328.08 $ 39.22 4.0 $ 156.87

Nontransient Noncommunity Water Systems (NTNCWSs)

≤100 $ 25.10 2.0 $ 50.20 $ 39.22 1.0 $ 39.22

101-500 $ 27.03 2.0 $ 54.06 $ 39.22 1.0 $ 39.22

501-1,000 $ 28.96 4.0 $ 115.84 $ 39.22 2.0 $ 78.44

1,001-4,100 $ 29.73 4.0 $ 118.92 $ 39.22 2.0 $ 78.44

4,101-33,000 $ 36.00 6.0 $ 216.00 $ 39.22 3.0 $ 117.65

33,001-96,000 $ 36.39 8.0 $ 291.12 $ 39.22 4.0 $ 156.87

96,001-500,000 $ 41.01 8.0 $ 328.08 $ 39.22 4.0 $ 156.87

500,001-1 Million $ 41.01 8.0 $ 328.08 $ 39.22 4.0 $ 156.87

> 1 Million $ 41.01 8.0 $ 328.08 $ 39.22 4.0 $ 156.87

Transient Noncommunity Water Systems (TNCWSs)

≤100 $ 25.10 2.0 $ 50.20 $ 39.22 1.0 $ 39.22

101-500 $ 27.03 2.0 $ 54.06 $ 39.22 1.0 $ 39.22

501-1,000 $ 28.96 4.0 $ 115.84 $ 39.22 2.0 $ 78.44

1,001-4,100 $ 29.73 4.0 $ 118.92 $ 39.22 2.0 $ 78.44

4,101-33,000 $ 36.00 6.0 $ 216.00 $ 39.22 3.0 $ 117.65

33,001-96,000 $ 36.39 8.0 $ 291.12 $ 39.22 4.0 $ 156.87

96,001-500,000 $ 41.01 8.0 $ 328.08 $ 39.22 4.0 $ 156.87

500,001-1 Million $ 41.01 8.0 $ 328.08 $ 39.22 4.0 $ 156.87

> 1 Million $ 41.01 8.0 $ 328.08 $ 39.22 4.0 $ 156.87

Notes: 

Sources:

(A) Labor rates for systems from Exhibit 7.1.

(B) PWS labor hours to review and revise sample siting plans reflect EPA estimate.

(D) Labor rates for state employee from Section 7.2.1.

(E) State labor hours to review and revise sample siting plans reflect EPA estimate.

Revise Sample 

Siting Plan 

(hours/system)

PWS and state burden and cost estimates to review and revise sample siting plans are assumed to be identical under the RTCR and 

Alternative Option.

Unit Cost

State Labor 

Cost (per hour)

Review and 

Revise Sample 

Siting Plan 

(hours/system) Unit Cost

PWS Size

(Population

Served)

PWSs States

PWS Labor Cost 

(per hour)
Economic Analysis for the Final RTCR 7-12 September 2012 

Sample Siting Plan Net Cost Summary 

PWSs are expected to revise sample siting plans before monitoring begins. For modeling 

purposes costs are split between years 2 and 3 of the 25-year compliance period (monitoring is 

required starting in year 4). Total and net change in annualized present value cost estimates for 

PWSs to revise sample siting plans and states to review the revised sample siting plans (and 

consult with PWSs if necessary) under the 1989 TCR, RTCR, and Alternative option are 

presented in Exhibit 7.7. 

Exhibit 7.7 Annualized Cost Estimates to Revise (PWSs) and Review (States) 

Sample Siting Plans ($Millions, 2007$) 

PWSs State Total PWSs State Total

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total $ 0.59 0.42$ $ 1.01 $ 0.84 $ 0.59 $ 1.42

RTCR - Net Change $ 0.59 0.42$ $ 1.01 $ 0.84 $ 0.59 $ 1.42

Alternative Option - Total $ 0.59 0.42$ $ 1.01 $ 0.84 $ 0.59 $ 1.42

Alternative Option - Net Change $ 0.59 0.42$ $ 1.01 $ 0.84 $ 0.59 $ 1.42

Note: Detail may not add due to independent rounding.

Source: Final RTCR Cost Model.

3% Discount Rate 7% Discount Rate

7.4.3 Monitoring 

PWSs 

Monitoring costs for PWSs are calculated by multiplying the total numbers of routine, 

additional routine, and repeat samples required under the 1989 TCR, RTCR, and Alternative 

option (Exhibit 7.9) by the monitoring costs per sample presented in Exhibit 7.2. 

EPA assumed that the numbers of systems on monthly, quarterly, and annual monitoring 

remain unchanged at the rule effective date for a continuation of the 1989 TCR. For RTCR, EPA 

assumed that only systems that received an annual site visit under the 1989 TCR would continue 

on annual monitoring; systems that would no longer qualify for annual monitoring under the 

RTCR were assumed to revert to baseline quarterly monitoring. (See section 7.4.4 for more 

information regarding annual site visits.) Under the Alternative option, all PWSs, regardless of 

size or type, start at monthly monitoring at the rule effective date. These differences in 

monitoring requirements between the 1989 TCR and the RTCR and Alternative option, which 

are presented in more detail in Exhibit 7.8 below, drive the differences in monitoring costs 

between the options. Chapters 4 (Exhibit 4.4) and 5 (Exhibit 5.9a–5.9c) show the distribution of 

monitoring frequencies prior to and after rule implementation, that are used to further inform the 

analysis. The effects of the differences in monitoring regimes on net changes in costs are 

described in further detail following the exhibit.
Economic Analysis for the Final RTCR 7-13 September 2012 

Exhibit 7.8 Summary of Monitoring Requirements Under the 1989 TCR, RTCR, and Alternative Option 

Monitoring 

Requirement 1989 TCR RTCR Alternative Option

Default Routine 

Monitoring Frequency

The default TC monitoring frequency for 

ground water Noncommunity Water Systems 

(NCWSs) serving ≤1,000 people is quarterly

The default TC monitoring frequency for all 

other PWSs is monthly for TC

The default TC monitoring frequency for nonseasonal ground water NCWSs serving ≤1,000 

people is quarterly

The default TC monitoring frequency for all other 

PWSs is monthly

PWSs would be permitted to transition to the 

RTCR at their current TC monitoring 

frequencies52

The default TC monitoring frequency for all PWSs 

is monthly

All PWSs would start on monthly TC monitoring

Reduced/Increased 

Routine Monitoring

Frequency

Ground water NCWSs serving ≤1,000 

people can reduce to annual monitoring if no 

sanitary defects and served only by 

protected GW sources

Ground water CWSs serving ≤1,000 can 

reduce to quarterly monitoring if no history of 

TC+ in current configuration, no sanitary 

defects, and served only by protected GW

sources

All other PWSs are ineligible for reduced 

monitoring 

PWSs not meeting criteria for reduced 

monitoring return to default monitoring (no 

increased monitoring provision under 1989

TCR)

Ground water NCWSs serving ≤1,000 people can 

reduce to annual monitoring if no sanitary 

defects, clean compliance history for minimum of 

12 months, and annual site visit or Level 2 

assessment, and correction of all identified 

sanitary defects

Ground water CWSs serving ≤1,000 people can 

reduce to quarterly monitoring if no sanitary 

defects, clean compliance history for a minimum 

of 12 months, and at least one of the following:

1) Annual site visit or voluntary Level 2 

assessment and correction of all identified 

sanitary defects; 

2) An approved cross connection control 

program;

3) Continuous disinfection & a residual; 

4) 4-log inactivation of viruses daily as per GWR 

(4-hr exception allowed); or

5) Other equivalent measures as approved by 

the primacy agency.

All other PWSs are ineligible for reduced 

Ground water NCWSs serving ≤1,000 people can 

reduce to quarterly monitoring if no sanitary 

defects, clean compliance history for minimum of 

12 months, and annual site visit or Level 2 

assessment, and correction of all identified sanitary 

defects.

Ground water CWSs serving ≤1,000 people can 

reduce to quarterly monitoring if no sanitary 

defects, clean compliance history for a minimum of 

12 months, and at least one of the following:

1) Annual site visit or voluntary Level 2 assessment 

and correction of all identified sanitary defects; 

2) An approved cross connection control program;

3) Continuous disinfection & a residual; 

4) 4-log inactivation of viruses daily as per GWR (4 

hour exception allowed); or

5) Other equivalent measures as approved by the 

primacy agency.

All other PWSs are ineligible for reduced 

 

52 In order for PWSs to be able to transition to the RTCR at their current TC monitoring frequencies, an annual site visit or voluntary Level 2 assessment would 

be needed in the first year for PWSs on annual monitoring, including those transitioning. 
Economic Analysis for the Final RTCR 7-14 September 2012 

Monitoring 

Requirement 1989 TCR RTCR Alternative Option

monitoring

Ground water PWSs serving ≤1,000 people on 

quarterly or annual monitoring that experience 

any of the following events will be required to 

begin monthly monitoring:

1) System triggers a Level 2 assessment (or a 

2nd Level 1 assessment in a rolling 12-month 

period);

2) System has an E. coli Maximum Contaminant 

Level (MCL) violation;

3) System has an RTCR treatment technique 

violation (either Level 1 or 2); or

4) System has two monitoring violations in a 

rolling 12-month period.

5) NCWSs serving ≤1,000 increase from 

quarterly to monthly monitoring if system has one 

monitoring violation and one Level 1 assessment 

within 12 months.

6) NCWSs serving ≤1,000 increase from annual 

to quarterly monitoring if system has one 

monitoring violation.

monitoring

Ground water PWSs serving ≤1,000 people on 

quarterly monitoring that experience any of the 

following events will be required to begin monthly 

monitoring (i.e., return to default monitoring 

frequency):

1) System triggers a Level 2 assessment (or a 2nd 

Level 1 assessment in a rolling 12-month period);

2) System has an E. coli MCL violation;

3) System has an RTCR treatment technique 

violation (either Level 1 or 2); or

4) System has two monitoring violations in a rolling 

12-month period.

5) NCWSs serving ≤1,000 increase from quarterly 

to monthly monitoring if system has one monitoring 

violation and one Level 1 assessment within 12 

months.

6) NCWSs serving ≤1,000 increase from annual to 

quarterly monitoring if system has one monitoring 

violation.

Additional Routine

Monitoring Frequency

All PWSs serving ≤4,100 people must take 

at least 5 samples in the month following a 

TC+ unless state performs site visit and 

deems additional sampling unnecessary OR 

determines the reason for the TC+ and PWS

has or will correct problem.

Not required for PWSs serving >4,100 

people

Ground water NCWSs serving ≤1,000 people 

and monitoring quarterly or annually must take at 

least 3 samples in the month following TC+

Ground water CWSs serving ≤1,000 people and

monitoring quarterly must take at least 3 samples 

in the month following TC+ 

Not required for PWSs monitoring monthly

Ground water PWSs (NCWS and CWS) serving 

≤1,000 people and monitoring quarterly must take 

at least 3 samples in the month following TC+

Not required for PWSs monitoring monthly

Repeat Monitoring

Frequency

All PWSs serving ≤1,000 people must take 4 

repeat TC samples

All PWSs serving >1,000 people must take 3 

repeat TC samples 

All PWSs must take 3 repeat TC samples All PWSs must take 3 repeat TC samples
Economic Analysis for the Final RTCR 7-15 September 2012 

Routine Monitoring 

Under the RTCR, the increased stringency to qualify for reduced monitoring results in 

more routine samples being taken over time (fewer PWSs are on reduced monitoring) for most 

PWS sizes and types. The only PWSs predicted to have a decrease in routine monitoring under 

the RTCR are ground water NTNCWSs serving ≤1,000 people due to more PWSs monitoring 

quarterly than under the 1989 TCR. For the Alternative option, this effect would be combined 

with the requirement that all PWSs start the implementation period on monthly monitoring, 

resulting in more routine samples being taken for all PWS sizes and types. The Alternative 

option also prohibits annual monitoring leading to an even greater increase in the number of 

routine samples. The resulting increases in total national costs due to increased monitoring on the 

national level are reflected in the routine monitoring costs shown in Exhibit 7.10. 

Additional Routine Monitoring53

The overall reductions in additional routine samples required under the RTCR and 

Alternative option result in reduced costs (Exhibit 7.10). Under the RTCR and Alternative 

option, additional routine monitoring is no longer required for systems that monitor at least 

monthly, and when additional routine monitoring is required, the number of samples required is 

reduced from five to three. Cost reductions are greater under the Alternative option than under 

the RTCR because all PWSs start on monthly monitoring and are not required to take additional 

routine samples during that period. 

Repeat Monitoring 

Under the RTCR and Alternative option, all PWSs are only required to take three repeat 

samples. However, EPA assumes that ground water PWSs treating to less than 4-log would still 

take an additional source water sample to comply with the GWR (no change in cost). 

Additionally, the number of repeat samples taken is a function of the number of regular and 

additional routine samples taken, which in turn affects the number of TC+ samples found (i.e., 

the more samples taken, the greater chance of finding a TC+). Thus, the overall increase in 

routine sampling under the RTCR and Alternative option would result in more repeat samples 

while the decreases in additional routine samples under both of these options would lead to fewer 

repeat samples. 

In most PWS size and type categories, the large reductions in additional routine 

monitoring samples is the major driver, leading to decreases in repeat samples. Under the RTCR, 

only ground water TNCWSs serving ≤100 people are predicted to see an increase repeat 

sampling due to the large increase in routine sampling within this category. Under the 

Alternative option, ground water NTNCWSs and TNCWSs serving ≤1,000 people are predicted 

to have increased repeat monitoring as a function of large increases in routine monitoring. The 

overall effect on the national level is a reduction in the number (and cost) of required repeat 

samples under the RTCR and an increase under the Alternative option compared to the 1989 

TCR (Exhibit 7.10). 

 

53 For modeling purposes and discussion throughout the cost chapter, regular routine monitoring samples taken in 

the month following a TC+ are included in the additional routine monitoring sample counts. 
Economic Analysis for the Final RTCR 7-16 September 2012 

Cumulative Monitoring Summary 

Exhibit 7.9 summarizes the total number of samples taken by PWS size and category for 

routine, additional, and repeat monitoring under the 1989 TCR, RTCR, and Alternative option 

over the entire 25-year period of analysis. Appendix A presents additional information on 

samples taken for each individual year during the analysis period. 

States 

Under the 1989 TCR, states are estimated to incur a monthly 15-minute burden to review 

each PWS’s sample results. This estimate reflects the methodology used to calculate reporting 

and recordkeeping burden under the 1989 TCR in the Information Collection Request for the 

Microbial Rules (USEPA, 2008b). Because the existing methodology is calculated on a per PWS 

basis and the total number of PWSs is the same for cost modeling under the 1989 TCR, RTCR, 

and Alternative option, the net change in costs for reviewing monitoring results is estimated to be 

zero for the RTCR and Alternative option. Specific actions by states related to positive samples 

are accounted for under the actions required in response to those samples. Maintenance of 

sample results in SDWIS is accounted for under general implementation and administrative 

activities, which are discussed in Section 7.4.1. 

Monitoring Net Cost Summary 

Total and net change in annualized present value cost estimates for PWSs and states to 

perform monitoring under the 1989 TCR, RTCR, and Alternative option are presented in Exhibit 

7.10. All monitoring is modeled to begin in year 4 of the 25-year analysis period. 

The overall estimated increase in monitoring costs seen under the RTCR is driven by 

increases in routine monitoring due to stricter requirements to qualify for reduced monitoring. 

However, this is mostly offset by reductions in additional routine and repeat monitoring required 

under the revised regulation. For the Alternative option, the requirement for all PWSs to sample 

on a monthly basis at the beginning of rule implementation results in a large cost differential that 

is only partially offset by reduced costs due to reductions in additional routine monitoring 

requirements. Although not shown in Exhibit 7.10, costs for individual PWS categories (size and 

type) are expected to move in the same direction relative to the numbers of samples taken as 

reflected in Exhibit 7.9. Exceptions to the general trends on the national level are discussed in the 

subsections describing routine, additional routine, and repeat sampling above. 
Economic Analysis for the Final RTCR 7-17 September 2012 

Exhibit 7.9 Cumulative Number of Samples over 25-Year Period of Analysis 

Routine 

Monitoring 

Samples

Additional 

Routine 

Monitoring 

Samples

Repeat 

Monitoring 

Samples

Routine 

Monitoring 

Samples

Additional 

Routine 

Monitoring 

Samples

Repeat 

Monitoring 

Samples

Routine 

Monitoring 

Samples

Additional 

Routine 

Monitoring 

Samples

Repeat 

Monitoring 

Samples

A B C D E F G H I

Community Water Systems (CWSs) - SW

≤100 304,247 23,167 18,698 308,880 13,764 - 308,880 13,764 - 

101-500 562,198 27,009 21,684 567,600 15,660 - 567,600 15,660 - 

501-1,000 306,605 15,334 12,299 309,672 8,708 - 309,672 8,708 - 

1,001-4,100 1,921,237 55,132 33,729 1,951,224 33,326 - 1,951,224 33,326 - 

4,101-33,000 10,636,296 186,729 - 10,636,296 181,661 - 10,636,296 181,661 - 

33,001-96,000 11,058,960 194,149 - 11,058,960 188,880 - 11,058,960 188,880 - 

96,001-500,000 10,190,400 178,901 - 10,190,400 174,046 - 10,190,400 174,046 - 

500,001-1 Million 2,019,600 35,456 - 2,019,600 34,493 - 2,019,600 34,493 - 

> 1 Million 1,686,960 29,616 - 1,686,960 28,812 - 1,686,960 28,812 - 

Total 38,686,502 120,642 38,729,592 711,259 679,350 - 38,729,592 679,350 - 

≤100 2,815,951 286,073 194,462 2,870,075 8,760 156,897 2,908,469 7,545 158,439 

101-500 3,344,578 243,895 171,252 3,391,200 6,127 136,906 3,428,876 5,264 137,959 

501-1,000 1,072,202 70,803 51,673 1,085,730 1,844 39,659 1,098,488 1,616 39,580

1,001-4,100 3,997,293 160,710 100,618 4,079,328 96,939 - 4,079,328 96,939 - 

4,101-33,000 9,145,224 230,201 - 9,145,224 217,321 - 9,145,224 217,321 - 

33,001-96,000 4,884,000 122,938 - 4,884,000 116,060 - 4,884,000 116,060 - 

96,001-500,000 1,945,680 48,976 - 1,945,680 46,236 - 1,945,680 46,236 - 

500,001-1 Million 253,440 6,380 - 253,440 6,023 - 253,440 6,023 - 

> 1 Million 269,280 6,778 - 269,280 6,399 - 269,280 6,399 - 

Total 27,727,648 761,481 27,923,956 933,279 16,731 28,012,784 822,439 14,425 824,956

≤100 65,018 4,910 3,991 66,000 3,040 - 66,000 3,040 - 

101-500 66,045 3,735 3,011 66,792 2,169 - 66,792 2,169 - 

501-1,000 22,976 1,278 1,029 23,232 - 23,232 756 - 756

1,001-4,100 41,759 2,142 1,348 42,768 1,228 - 42,768 1,228 - 

4,101-33,000 50,424 1,628 - 50,424 1,448 - 50,424 1,448 - 

33,001-96,000 34,320 1,108 - 34,320 - 34,320 985 - 985

96,001-500,000 31,680 1,023 - 31,680 - 31,680 910 - 910

500,001-1 Million - - - - - - - - -

> 1 Million - - - - - - - - -

Total 312,223 12,065 13,138 315,216 10,536 - 315,216 10,536 - 

≤100 971,538 128,775 84,992 932,025 48,142 68,123 1,314,175 36,965 91,416

101-500 725,785 66,525 43,597 678,688 25,630 35,860 976,627 19,382 48,269

501-1,000 190,649 16,037 10,680 180,145 6,166 8,601 249,760 4,802 11,817

1,001-4,100 460,470 28,214 17,790 473,352 15,887 - 473,352 15,887 - 

4,101-33,000 153,648 5,936 - 153,648 5,157 - 153,648 5,157 - 

33,001-96,000 23,760 - 23,760 918 - 23,760 797 - 797

96,001-500,000 - - - - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million - - - - - - - - -

Total 2,525,850 239,551 163,913 2,441,617 79,938 134,426 3,191,322 61,149 173,343

≤100 345,401 40,475 33,065 353,496 23,122 - 353,496 23,122 - 

101-500 128,156 15,261 12,454 131,208 8,192 - 131,208 8,192 - 

501-1,000 22,691 2,704 2,207 23,232 1,533 - 23,232 1,533 - 

1,001-4,100 40,151 4,155 2,707 42,240 2,312 - 42,240 2,312 - 

4,101-33,000 40,656 - 40,656 - 2,225 - 40,656 2,225 - 

33,001-96,000 - - - - - - - - -

96,001-500,000 - - - - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million 102,960 - 102,960 - 5,636 - 102,960 5,636 - 

Total 680,015 62,596 50,434 693,792 43,020 - 693,792 43,020 - 

≤100 4,493,808 905,554 600,315 6,076,163 446,166 631,105 9,524,123 333,524 912,589

101-500 1,614,924 316,238 210,714 1,940,946 135,822 194,697 3,021,771 104,732 282,740

501-1,000 177,264 32,730 22,064 206,130 14,078 20,078 304,534 10,412 27,932

1,001-4,100 335,283 29,957 19,113 348,480 16,027 - 348,480 16,027 - 

4,101-33,000 156,288 8,909 - 156,288 7,188 - 156,288 7,188 - 

33,001-96,000 34,320 1,956 - 34,320 1,578 - 34,320 1,578 - 

96,001-500,000 26,400 1,505 - 26,400 1,214 - 26,400 1,214 - 

500,001-1 Million 63,360 3,612 - 63,360 2,914 - 63,360 2,914 - 

> 1 Million - - - - - - - - -

Total 6,901,647 1,284,478 868,188 8,852,088 596,065 13,479,275 874,801 448,667 1,252,181

Grand Total 76,833,885 2,480,814 2,740,210 78,956,260 692,734 2,564,572 84,421,981 524,241 2,983,387

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

Transient Noncommunity Water Systems (TNCWSs) - SW

Transient Noncommunity Water Systems (TNCWSs) - GW

Source: Appendix A - Total PWS Counts (A.1z, A.2z, A.3z)

PWS Size

(Population

Served)

1989 TCR RTCR Alternative Option

Note: (B), (E), (H) For modeling purposes, additional routine sample counts include regular routine samples taken in the same month.

Community Water Systems (CWSs) - GW

Nontransient Noncommunity Water Systems (NTNCWSs) - SW
Economic Analysis for the Final RTCR 7-18 September 2012 

Exhibit 7.10 Annualized PWS and State Cost Estimates for Monitoring Costs 

($Millions, 2007$) 

PWSs State Total PWSs State Total

1989 TCR - Total $ 170.59 -$ 170.59 $ $ 163.94 -$ 163.94 $ 

RTCR - Total $ 174.71 -$ 174.71 $ $ 167.74 -$ 167.74 $ 

RTCR - Net Change $ 4.12 -$ $ 4.12 $ 3.80 -$ $ 3.80

RTCR - Percent Change 2.42% - 2.42% 2.32% - 2.32%

Alternative Option - Total $ 187.50 -$ 187.50 $ $ 182.48 -$ 182.48 $ 

Alternative Option - Net Change $ 16.91 -$ $ 16.91 $ 18.54 -$ $ 18.54

Alternative Option - Percent Change 9.91% - 9.91% 11.31% - 11.31%

1989 TCR - Total $ 3.87 -$ $ 3.87 $ 3.72 -$ $ 3.72

RTCR - Total $ 1.12 -$ $ 1.12 $ 1.09 -$ $ 1.09

RTCR - Net Change $ (2.75) -$ $ (2.75) $ (2.63) -$ $ (2.63)

RTCR - Percent Change -71.11% - -71.11% -70.75% - -70.75%

Alternative Option - Total $ 0.78 -$ $ 0.78 $ 0.66 -$ $ 0.66

Alternative Option - Net Change $ (3.10) -$ $ (3.10) $ (3.06) -$ $ (3.06)

Alternative Option - Percent Change -79.98% - -79.98% -82.29% - -82.29%

1989 TCR - Total $ 5.11 -$ $ 5.11 $ 4.92 -$ $ 4.92

RTCR - Total $ 4.88 -$ $ 4.88 $ 4.70 -$ $ 4.70

RTCR - Net Change $ (0.23) -$ $ (0.23) $ (0.22) -$ $ (0.22)

RTCR - Percent Change -4.53% - -4.53% -4.43% - -4.43%

Alternative Option - Total $ 5.66 -$ $ 5.66 $ 5.59 -$ $ 5.59

Alternative Option - Net Change $ 0.54 -$ $ 0.54 $ 0.67 -$ $ 0.67

Alternative Option - Percent Change 10.61% - 10.61% 13.71% - 13.71%

1989 TCR - Total $ 179.57 -$ 179.57 $ $ 172.57 -$ 172.57 $ 

RTCR - Total $ 180.71 -$ 180.71 $ $ 173.52 -$ 173.52 $ 

RTCR - Net Change $ 1.14 -$ $ 1.14 $ 0.95 -$ $ 0.95

RTCR - Percent Change 0.63% - 0.63% 0.55% - 0.55%

Alternative Option - Total $ 193.93 -$ 193.93 $ $ 188.72 -$ 188.72 $ 

Alternative Option - Net Change $ 14.36 -$ $ 14.36 $ 16.15 -$ $ 16.15

Alternative Option - Percent Change 7.99% - 7.99% 9.36% - 9.36%

Notes: 

1) Detail may not add due to independent rounding.

2) For modeling purposes, additional routine sample counts include regular routine samples taken in the same month.

Source: Final RTCR Cost Model.

3) State costs are premised on a per system basis. State costs for monitoring are expected to be identical under the 1989 TCR, RTCR, 

and Alternative Option, and are therefore not included in the total costs.

Routine Monitoring

3% Discount Rate 7% Discount Rate

Additional Routine Monitoring

Repeat Monitoring

Total
Economic Analysis for the Final RTCR 7-19 September 2012 

7.4.4 Annual Site Visits 

Under the RTCR, any PWS on an annual monitoring schedule would be required to also 

have an annual site visit conducted by the state or state-designated third party. A voluntary Level 

2 assessment can also satisfy the annual site visit requirement. In many cases a sanitary survey 

performed during the same year can also be used to satisfy this requirement.54 Although similar 

annual site visits are not currently required under the 1989 TCR, discussions with states during 

the TCRDSAC proceedings revealed that some do, in fact, conduct such inspections for PWSs 

on annual monitoring schedules. Because of the high cost for an annual site visit by a state, for 

this analysis, EPA assumes that no states would choose to conduct annual site visits unless they 

already do so under the 1989 TCR. Similarly, because of the high cost of the voluntary Level 2 

assessment relative to other options that PWSs have to comply with the rule (such as quarterly 

monitoring) it was assumed that any PWS that is currently on annual monitoring, but not 

receiving an annual site visit, would opt not to conduct a voluntary Level 2 assessment. 

Therefore, for overall costing purposes, no net change in state or PWS costs are assumed for 

annual monitoring site visits under the RTCR or Alternative option. 

7.4.5 Assessments

PWSs 

Level 1 Assessments 

Under the RTCR and Alternative option, all PWSs experiencing a Level 1 trigger must 

complete a Level 1 assessment of the PWS. A Level 1 trigger under the RTCR and Alternative 

option is defined as: 

 For PWSs taking ≥40 samples per month, TC+ exceeds 5.0% for a given month; 

 For PWSs taking <40 samples per month, two or more TC+ in a month; or 

 Failure to take all required repeat samples after a single TC+ sample. 

The 1989 TCR does not require a specific assessment to be performed in response to 

events comparable to the Level 1 triggers described above (i.e., non-acute violations). However, 

PWSs do perform some level of activity similar to a Level 1 assessment in response to 

violations. This effort is taken into account in the cost model to accurately assess the net cost of 

changes attributable to the RTCR. 

A Level 1 assessment is an evaluation to identify the possible presence of sanitary 

defects, defects in distribution system coliform monitoring practices, and (when possible) the 

likely reason that the system triggered the assessment. It is conducted by the system operator or 

 

54 In some instances, the performance of an assessment (especially a Level 2 assessment) may overlap with a 

scheduled sanitary survey. To the extent that the requirements for performing a sanitary survey may be satisfied as 

part of the assessment process, PWSs and states may realize a cost savings compared to performing a separate 

sanitary survey. This potential for indirect cost savings is not captured in the cost model, resulting in a potential 

overestimate of costs stemming from RTCR implementation. 
Economic Analysis for the Final RTCR 7-20 September 2012 

owner. Minimum elements include review and identification of atypical events that could affect 

distributed water quality or indicate that distributed water quality was impaired; changes in 

distribution system maintenance and operation that could affect distributed water quality 

(including water storage); source and treatment considerations that bear on distributed water 

quality, where appropriate (e.g., whether a ground water system is disinfected); existing water 

quality monitoring data; and inadequacies in sample sites, sampling protocol, and sample 

processing. The state may tailor specific assessment elements to the size and type of the system. 

Systems may tailor their assessment activities based on the characteristics of the distribution 

system (consistent with any state directives). Additionally, as part of the Level 1 assessment, 

PWSs would be required to submit to the state a form identifying sanitary defects detected, 

corrective actions completed, and a timetable for any corrective actions not already completed. 

Additional detail on the requirements of a Level 1 assessment and the derivation of associated 

unit burden (labor hours) for performance of the assessment is provided in the Technology and 

Cost Document for the Final Revised Total Coliform Rule (USEPA, 2010d).

Level 2 Assessments 

Under the RTCR and Alternative option, all PWSs experiencing a Level 2 trigger must 

complete a Level 2 assessment of the PWS. A Level 2 trigger under the RTCR and Alternative 

option is defined as: 

 An E. coli MCL violation; or 

 A second Level 1 treatment technique trigger, within a rolling 12-month period, 

unless the first Level 1 treatment technique trigger was based on exceeding the 

allowable number of TC+ samples, the state has determined a likely reason for the 

TC+ samples that caused the initial Level 1 treatment technique trigger, and the 

state establishes that the system has fully corrected the problem; or 

 For PWSs with approved reduced annual monitoring, a Level 1 trigger in two 

consecutive years. 

As with Level 1 assessments, the 1989 TCR does not require a specific assessment to be 

performed in response to events comparable to the Level 2 triggers described above (i.e., acute 

violations), but PWSs do currently perform some level of activity similar to a Level 2 assessment 

in response to acute violations. These actions are taken into account in the cost model to properly 

assess the net cost of changes attributable to the RTCR regulatory options. 

A Level 2 assessment (or comparable assessment under the 1989 TCR) would be more 

involved than a Level 1 assessment. A Level 2 assessment would be an evaluation to identify the 

possible presence of sanitary defects, defects in distribution system coliform monitoring 

practices, and (when possible) the likely reason that the system triggered the assessment. A Level 

2 assessment provides a more detailed examination of the system (including the system’s 

monitoring and operational practices) than does a Level 1 assessment through the use of more 

comprehensive investigation and review of available information, additional internal and 

external resources, and other relevant practices. It is conducted by an individual approved by the 

state, which may include the system operator. Minimum elements include review and 
Economic Analysis for the Final RTCR 7-21 September 2012 

identification of atypical events that could affect distributed water quality or indicate that 

distributed water quality was impaired; changes in distribution system maintenance and 

operation that could affect distributed water quality (including water storage); source and 

treatment considerations that bear on distributed water quality, where appropriate (e.g., whether a 

ground water system is disinfected); existing water quality monitoring data; and inadequacies in 

sample sites, sampling protocol, and sample processing. The state may tailor specific assessment 

elements to the size and type of the system. The state may also direct expedited actions or 

additional actions in the case of an E. coli MCL violation. Systems may tailor their assessment 

activities based on the characteristics of the distribution system (consistent with any state 

directives). Additionally, as part of the Level 2 assessment, PWSs must submit to the state a 

form identifying sanitary defects detected, corrective actions completed, and a timetable for 

completion of any corrective actions that not already completed. Additional detail on the 

derivation of associated unit burden (labor hours) for performance of the assessment is provided 

in the Technology and Cost Document for the Final Revised Total Coliform Rule (USEPA,

2010d).

The labor rates presented in Section 7.2.1 are used along with estimates of labor hours as 

presented in the Technology and Cost Document for the Final Revised Total Coliform Rule

(USEPA, 2010d) to generate Level 1 and Level 2 assessment unit costs by PWS size and type. 

Labor hours provided are assumed to include time for reporting and recordkeeping activities. 

Estimates of PWS unit costs for Level 1 and Level 2 assessments are presented in Exhibits 7.11 

and 7.12. Additionally, the numbers of Level 1 and level 2 assessments over the 25-year 

compliance period (used to calculate total costs) are presented in Exhibit 7.13.
Economic Analysis for the Final RTCR 7-22 September 2012 

Exhibit 7.11 PWS Unit Costs Estimates for Assessment Activities 

(1989 TCR) (2007$) 

A B C=A*B D E=A*D F G=A*F

≤100 $ 25.10 11.0 $ 276.10 14.0 $ 351.40 14.0 $ 351.40

101-500 $ 27.03 11.0 $ 297.33 14.0 $ 378.42 14.0 $ 378.42

501-1,000 $ 28.96 13.0 $ 376.48 15.0 $ 434.40 15.0 $ 434.40

1,001-4,100 $ 29.73 22.0 $ 654.06 29.0 $ 862.17 29.0 $ 862.17

4,101-33,000 $ 36.00 30.0 $ 1,080.00 36.0 1,296.00 $ 36.0 $ 1,296.00

33,001-96,000 $ 36.39 59.0 $ 2,147.01 75.0 2,729.25 $ 75.0 $ 2,729.25

96,001-500,000 $ 41.01 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

500,001-1 Million 41.01 $ 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

> 1 Million $ 41.01 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

≤100 $ 25.10 11.0 $ 276.10 14.0 $ 351.40 14.0 $ 351.40

101-500 $ 27.03 11.0 $ 297.33 14.0 $ 378.42 14.0 $ 378.42

501-1,000 $ 28.96 13.0 $ 376.48 15.0 $ 434.40 15.0 $ 434.40

1,001-4,100 $ 29.73 22.0 $ 654.06 29.0 $ 862.17 29.0 $ 862.17

4,101-33,000 $ 36.00 30.0 $ 1,080.00 36.0 1,296.00 $ 36.0 $ 1,296.00

33,001-96,000 $ 36.39 59.0 $ 2,147.01 75.0 2,729.25 $ 75.0 $ 2,729.25

96,001-500,000 $ 41.01 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

500,001-1 Million 41.01 $ 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

> 1 Million $ 41.01 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

≤100 $ 25.10 4.0 $ 100.40 6.0 $ 150.60 6.0 $ 150.60

101-500 $ 27.03 4.0 $ 108.12 6.0 $ 162.18 6.0 $ 162.18

501-1,000 $ 28.96 4.0 $ 115.84 6.0 $ 173.76 6.0 $ 173.76

1,001-4,100 $ 29.73 4.0 $ 118.92 6.0 $ 178.38 6.0 $ 178.38

4,101-33,000 $ 36.00 30.0 $ 1,080.00 36.0 1,296.00 $ 36.0 $ 1,296.00

33,001-96,000 $ 36.39 59.0 $ 2,147.01 75.0 2,729.25 $ 75.0 $ 2,729.25

96,001-500,000 $ 41.01 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

500,001-1 Million 41.01 $ 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

> 1 Million $ 41.01 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

≤100 $ 25.10 4.0 $ 100.40 6.0 $ 150.60 6.0 $ 150.60

101-500 $ 27.03 4.0 $ 108.12 6.0 $ 162.18 6.0 $ 162.18

501-1,000 $ 28.96 4.0 $ 115.84 6.0 $ 173.76 6.0 $ 173.76

1,001-4,100 $ 29.73 4.0 $ 118.92 6.0 $ 178.38 6.0 $ 178.38

4,101-33,000 $ 36.00 30.0 $ 1,080.00 36.0 1,296.00 $ 36.0 $ 1,296.00

33,001-96,000 $ 36.39 59.0 $ 2,147.01 75.0 2,729.25 $ 75.0 $ 2,729.25

96,001-500,000 $ 41.01 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

500,001-1 Million 41.01 $ 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

> 1 Million $ 41.01 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

≤100 $ 25.10 4.0 $ 100.40 6.0 $ 150.60 6.0 $ 150.60

101-500 $ 27.03 4.0 $ 108.12 6.0 $ 162.18 6.0 $ 162.18

501-1,000 $ 28.96 4.0 $ 115.84 6.0 $ 173.76 6.0 $ 173.76

1,001-4,100 $ 29.73 4.0 $ 118.92 6.0 $ 178.38 6.0 $ 178.38

4,101-33,000 $ 36.00 30.0 $ 1,080.00 36.0 1,296.00 $ 36.0 $ 1,296.00

33,001-96,000 $ 36.39 59.0 $ 2,147.01 75.0 2,729.25 $ 75.0 $ 2,729.25

96,001-500,000 $ 41.01 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

500,001-1 Million 41.01 $ 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

> 1 Million $ 41.01 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

≤100 $ 25.10 4.0 $ 100.40 6.0 $ 150.60 6.0 $ 150.60

101-500 $ 27.03 4.0 $ 108.12 6.0 $ 162.18 6.0 $ 162.18

501-1,000 $ 28.96 4.0 $ 115.84 6.0 $ 173.76 6.0 $ 173.76

1,001-4,100 $ 29.73 4.0 $ 118.92 6.0 $ 178.38 6.0 $ 178.38

4,101-33,000 $ 36.00 30.0 $ 1,080.00 36.0 1,296.00 $ 36.0 $ 1,296.00

33,001-96,000 $ 36.39 59.0 $ 2,147.01 75.0 2,729.25 $ 75.0 $ 2,729.25

96,001-500,000 $ 41.01 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

500,001-1 Million 41.01 $ 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

> 1 Million $ 41.01 108.0 $ 4,429.08 117.0 $ 4,798.17 117.0 $ 4,798.17

Note:

Sources:

(A) Labor rates for PWSs from Exhibit 7.1.

(B), (D), (F) Final RTCR T&C Document. 

(F) EPA assumes that the burden incurred by operators to assess their PWSs follow ing a second non-acute violation is equal to the burden incurred by an 

assessment follow ing an acute violation.

Transient Noncommunity Water Systems (TNCWSs) - GW

Transient Noncommunity Water Systems (TNCWSs) - SW

Non-Acute 

Violations (single 

violation) (hours) Unit Cost

Acute 

Violations 

(hours)

Community Water Systems (CWSs) - GW

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

Unit Cost

Community Water Systems (CWSs) - SW

Activities Similar to Level 1 Assessments Activities Similar to Level 2 Assessments

PWS Size 

(Population 

Served)

Labor Cost 

(per hour)

Non-Acute 

Violations 

(multiple 

violations) 

(hours) Unit Cost
Economic Analysis for the Final RTCR 7-23 September 2012 

Exhibit 7.12 PWS Unit Costs Estimates for Level 1 and Level 2 Assessments 

(RTCR and Alternative Option) (2007$) 

A B C=A*B D E=A*D F G=A*F

≤100 $ 25.10 19.0 $ 476.90 23.0 $ 577.30 22.0 $ 552.20

101-500 $ 27.03 19.0 $ 513.57 23.0 $ 621.69 22.0 $ 594.66

501-1,000 $ 28.96 20.0 $ 579.20 24.0 $ 695.04 23.0 $ 666.08

1,001-4,100 $ 29.73 31.0 $ 921.63 48.0 1,427.04 $ 46.0 $ 1,367.58

4,101-33,000 $ 36.00 1,476.00 41.0 $ 71.0 2,556.00 $ 69.0 $ 2,484.00

33,001-96,000 $ 36.39 2,474.52 68.0 $ 121.0 $ 4,403.19 116.0 $ 4,221.24

96,001-500,000 $ 41.01 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

500,001-1 Million 41.01 $ 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

> 1 Million $ 41.01 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

≤100 $ 25.10 19.0 $ 476.90 23.0 $ 577.30 22.0 $ 552.20

101-500 $ 27.03 19.0 $ 513.57 23.0 $ 621.69 22.0 $ 594.66

501-1,000 $ 28.96 20.0 $ 579.20 24.0 $ 695.04 23.0 $ 666.08

1,001-4,100 $ 29.73 31.0 $ 921.63 48.0 1,427.04 $ 46.0 $ 1,367.58

4,101-33,000 $ 36.00 1,476.00 41.0 $ 71.0 2,556.00 $ 69.0 $ 2,484.00

33,001-96,000 $ 36.39 2,474.52 68.0 $ 121.0 $ 4,403.19 116.0 $ 4,221.24

96,001-500,000 $ 41.01 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

500,001-1 Million 41.01 $ 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

> 1 Million $ 41.01 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

≤100 $ 25.10 7.0 $ 175.70 21.0 $ 527.10 9.0 $ 225.90

101-500 $ 27.03 7.0 $ 189.21 21.0 $ 567.63 9.0 $ 243.27

501-1,000 $ 28.96 7.0 $ 202.72 21.0 $ 608.16 9.0 $ 260.64

1,001-4,100 $ 29.73 8.0 $ 237.84 29.0 $ 862.17 10.0 $ 297.30

4,101-33,000 $ 36.00 1,476.00 41.0 $ 71.0 2,556.00 $ 69.0 $ 2,484.00

33,001-96,000 $ 36.39 2,474.52 68.0 $ 121.0 $ 4,403.19 116.0 $ 4,221.24

96,001-500,000 $ 41.01 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

500,001-1 Million 41.01 $ 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

> 1 Million $ 41.01 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

≤100 $ 25.10 7.0 $ 175.70 21.0 $ 527.10 9.0 $ 225.90

101-500 $ 27.03 7.0 $ 189.21 21.0 $ 567.63 9.0 $ 243.27

501-1,000 $ 28.96 7.0 $ 202.72 21.0 $ 608.16 9.0 $ 260.64

1,001-4,100 $ 29.73 8.0 $ 237.84 29.0 $ 862.17 10.0 $ 297.30

4,101-33,000 $ 36.00 1,476.00 41.0 $ 71.0 2,556.00 $ 69.0 $ 2,484.00

33,001-96,000 $ 36.39 2,474.52 68.0 $ 121.0 $ 4,403.19 116.0 $ 4,221.24

96,001-500,000 $ 41.01 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

500,001-1 Million 41.01 $ 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

> 1 Million $ 41.01 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

≤100 $ 25.10 7.0 $ 175.70 21.0 $ 527.10 9.0 $ 225.90

101-500 $ 27.03 7.0 $ 189.21 21.0 $ 567.63 9.0 $ 243.27

501-1,000 $ 28.96 7.0 $ 202.72 21.0 $ 608.16 9.0 $ 260.64

1,001-4,100 $ 29.73 8.0 $ 237.84 29.0 $ 862.17 10.0 $ 297.30

4,101-33,000 $ 36.00 1,476.00 41.0 $ 71.0 2,556.00 $ 69.0 $ 2,484.00

33,001-96,000 $ 36.39 2,474.52 68.0 $ 121.0 $ 4,403.19 116.0 $ 4,221.24

96,001-500,000 $ 41.01 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

500,001-1 Million 41.01 $ 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

> 1 Million $ 41.01 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

≤100 $ 25.10 7.0 $ 175.70 21.0 $ 527.10 9.0 $ 225.90

101-500 $ 27.03 7.0 $ 189.21 21.0 $ 567.63 9.0 $ 243.27

501-1,000 $ 28.96 7.0 $ 202.72 21.0 $ 608.16 9.0 $ 260.64

1,001-4,100 $ 29.73 8.0 $ 237.84 29.0 $ 862.17 10.0 $ 297.30

4,101-33,000 $ 36.00 1,476.00 41.0 $ 71.0 2,556.00 $ 69.0 $ 2,484.00

33,001-96,000 $ 36.39 2,474.52 68.0 $ 121.0 $ 4,403.19 116.0 $ 4,221.24

96,001-500,000 $ 41.01 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

500,001-1 Million 41.01 $ 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

> 1 Million $ 41.01 159.0 $ 6,520.59 10,334.52 252.0 $ 238.0 $ 9,760.38

Sources:

(A) Labor rates for PWSs from Exhibit 7.1.

(B), (D), (F) Final RTCR T&C Document.

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

Level 2 Triggers 

(triggered by 

multiple Level 1s) 

(hours) Unit Cost

Community Water Systems (CWSs) - SW

Community Water Systems (CWSs) - GW

Transient Noncommunity Water Systems (TNCWSs) - GW

Transient Noncommunity Water Systems (TNCWSs) - SW

Labor Cost 

(per hour)

PWS Size

(Population

Served)

Level 1 Assessments Level 2 Assessments

Non-Acute 

Trigger 

(single trigger) 

(hours) Unit Cost

Acute 

Violations 

(hours) Unit Cost
Economic Analysis for the Final RTCR 7-24 September 2012 

Exhibit 7.13 Number of Level 1 and Level 2 Assessments over the 25-Year 

Compliance Period 

Activities 

Similar to 

Level 1 

Assessments

Level 1 

Assessments

Level 1 

Assessments

A B C D E F G H I

Community Water Systems (CWSs) - SW

≤100 525 157 184 400 100 102 400 100 102

101-500 649 167 111 539 119 75 539 119 75

501-1,000 361 102 63 277 75 40 277 75 40

1,001-4,100 954 162 149 920 146 132 920 146 132

4,101-33,000 2,152 197 - 2,152 197 - 2,152 197 -

33,001-96,000 534 56 - 534 56 - 534 56 -

96,001-500,000 233 24 - 233 24 - 233 24 -

500,001-1 Million 22 - - 22 - - 22 - -

> 1 Million - - - - - - - - -

Total 5,429 865 507 5,076 717 349 5,076 717 349

≤100 9,772 1,141 5,383 8,004 853 3,523 7,871 926 3,272 

101-500 8,169 1,025 4,214 6,502 696 2,399 6,495 747 2,543 

501-1,000 2,250 284 1,050 1,780 188 626 1,772 203 607

1,001-4,100 3,545 477 2,808 3,208 342 1,705 3,208 342 1,705 

4,101-33,000 4,545 263 - 4,545 263 - 4,545 263 -

33,001-96,000 656 53 - 656 53 - 656 53 -

96,001-500,000 129 10 - 129 10 - 129 10 -

500,001-1 Million - - - - - - - - -

> 1 Million - - - - - - - - -

Total 29,066 3,253 13,455 24,824 2,405 8,253 24,675 2,544 8,127

≤100 98 35 77 75 28 41 75 28 41

101-500 88 29 40 69 19 24 69 19 24

501-1,000 30 9 13 24 6 9 24 6 9

1,001-4,100 42 19 37 37 13 23 37 13 23

4,101-33,000 5 - - 5 - - 5 - -

33,001-96,000 - - - - - - - - -

96,001-500,000 - - - - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million - - - - - - - - -

Total 262 93 167 209 67 98 209 67 98

≤100 5,581 856 3,829 4,797 559 2,010 5,673 723 3,390 

101-500 3,130 447 1,273 2,794 315 757 3,551 446 1,333 

501-1,000 744 95 298 675 79 168 814 99 298

1,001-4,100 818 169 974 690 114 530 690 114 530

4,101-33,000 123 9 - 123 9 - 123 9 - 

33,001-96,000 4 - - 4 - - 4 - -

96,001-500,000 - - - - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million - - - - - - - - -

Total 10,400 1,577 6,373 9,084 1,077 3,466 10,855 1,393 5,551

≤100 1,093 430 780 796 250 425 796 250 425

101-500 410 170 320 278 90 154 278 90 154

501-1,000 67 28 47 50 17 25 50 17 25

1,001-4,100 92 50 128 73 29 69 73 29 69

4,101-33,000 8 - - 8 - - 8 - -

33,001-96,000 - - - - - - - - -

96,001-500,000 - - - - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million - - - - - - - - -

Total 1,670 677 1,275 1,204 386 674 1,204 386 674

≤100 44,730 6,649 25,425 47,190 5,477 20,628 57,597 7,796 37,532 

101-500 14,530 2,089 8,864 13,780 1,608 5,694 17,358 2,441 10,924 

501-1,000 1,477 221 896 1,396 177 585 1,661 230 1,015 

1,001-4,100 927 186 1,138 773 117 638 773 117 638

4,101-33,000 116 4 - 116 4 - 116 4 - 

33,001-96,000 - - - - - - - - -

96,001-500,000 - - - - - - - - -

500,001-1 Million - - - - - - - - -

> 1 Million - - - - - - - - -

Total 61,780 9,149 36,324 63,256 7,383 27,546 77,506 10,589 50,109

Grand Total 108,608 15,613 58,102 103,653 12,035 40,385 119,526 15,695 64,908

Notes: 

1) Detail may not add due to rounding.

Sources:

(A), (B), (C) - A.1.z

(D), (E), (F) - A.2.z

(G), (H), (I) - A.3.z

2) Assessments conducted under the 1989 TCR are not labeled as Level 1 and Level 2 assessments; how ever they are similar to the assessments under the 

RTCR and Alternative option.

Level 2 

Triggers 

(triggered 

by multiple 

Level 1s)

Level 2 

Assessments

1989 TCR

Non-Acute 

Violations 

(single 

violation)

Non-Acute 

Trigger 

(single 

trigger)

Acute 

Violations

PWS Size

(Population

Served)

Level 2 

Assessments

RTCR Alternative Option

Acute 

Violations

Activities Similar to 

Level 2 

Assessments

Acute 

Violations

Level 2 

Triggers 

(triggered 

by multiple 

Level 1s)

Non-Acute 

Trigger 

(single 

trigger)

Transient Noncommunity Water Systems (TNCWSs) - GW

Community Water Systems (CWSs) - GW

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

Transient Noncommunity Water Systems (TNCWSs) - SW

Non-Acute 

Violations 

(multiple 

violations)
Economic Analysis for the Final RTCR 7-25 September 2012 

States 

Level 1 and Level 2 Assessments 

Under the 1989 TCR, RTCR and Alternative option, states would incur burden to review 

the completed assessment forms required to be filed by PWSs (or similar reports required by 

states under the 1989 TCR). Although some states may choose to conduct assessments for their 

PWSs, EPA does not quantify these costs since this is not a regulatory requirement. State costs 

are based on the number of PWSs submitting assessment reports. The state labor rate presented 

in Section 7.2.1 and estimates of labor hours are used to generate state Level 1 and Level 2 

assessment unit costs. EPA estimates that state burden to review PWS assessment forms would 

range from one to eight hours depending on PWS size and type, as well as the level of the 

assessment. This burden includes any time required to consult with the PWS about the 

assessment report. Estimates of state unit costs for Level 1 and Level 2 assessments are presented 

in Exhibit 7.14. 

Assessment Net Cost Summary 

Annualized cost estimates for Level 1 and Level 2 assessments under the 1989 TCR, 

RTCR, and Alternative option are calculated by multiplying the number of assessments 

estimated by the predictive modeling (summarized in Exhibit 7.13) by the unit costs presented in 

Exhibits 7.11, 7.12, and 7.14. Exhibit 7.13 presents the estimated totals of non-acute and acute 

MCL violations (1989 TCR) and Level 1 and Level 2 assessments (RTCR and Alternative 

option). The model predicts a total of approximately 109,000 single non-acute MCL violations, 

58,000 cases of a second non-acute MCL violation, and 16,000 acute MCL violations for the 

1989 TCR under which some PWSs do currently engage in some assessment activity which may 

or may not meet the RTCR criteria (see section 7.4.5). For the RTCR, the model predicts 

approximately 104,000 Level 1 assessments and 52,000 Level 2 assessments. For the Alternative 

option, the model predicts approximately 120,000 Level 1 assessments and 81,000 Level 2 

assessments. (Appendix A provides a detailed breakout of the number of Level 1 and Level 2 

assessments estimated by the occurrence model.) Total and net change in annualized present 

value cost estimates for PWSs and states to perform Level 1 and Level 2 assessments under the 

1989 TCR, RTCR, and Alternative option are presented in Exhibit 7.15 below. 

Under the RTCR, all PWSs are required to conduct assessments of their systems when 

they exceed Level 1 or Level 2 treatment technique triggers. While PWSs are not required to 

conduct assessments under the 1989 TCR, some PWSs do currently engage in some assessment 

activity (which may or may not meet the RTCR criteria) following non-acute and acute MCL 

violations. EPA estimates both the costs to PWSs to conduct assessments under the RTCR as 

well as the level of effort that PWSs already put towards assessment activities under the 1989 

TCR; these estimates are based on the work of the stakeholders in the TWG during the 

proceedings of the TCRDSAC. These estimates allowed EPA to determine the average net costs 

to conduct assessments under the RTCR. EPA assumes that the numbers of non-acute and acute 

MCL violations would remain steady under a continuation of the 1989 TCR (based on review of 

SDWIS/FED violation data). Under the RTCR, EPA assumes that the numbers of assessment 

triggers decrease over time from the steady state level estimate based on the 1989 TCR to a new 
Economic Analysis for the Final RTCR 7-26 September 2012 

steady state level, as a result of reduced fecal indicator occurrence associated with the beneficial 

effects of requiring assessments and corrective action. 

The overall number of assessments increases under the Alternative option. This is a result 

of the initial monthly monitoring requirements for all PWSs under this analysis. The modeling 

results indicate that the much higher sampling early on after the rule’s effective date would result 

in more positive samples and associated assessments despite the predicted long term reductions 

in occurrence. This increase in total assessments performed, combined with the higher unit cost 

of performing assessments compared to existing practices under the 1989 TCR, results in a 

higher net cost increase for PWSs under the Alternative option than under the RTCR. For states, 

the increase in the number of assessments is estimated to translate directly to a cost increase. The 

total net change in cost for the Alternative option is estimated to be positive, and greater than 

under the RTCR. 
Economic Analysis for the Final RTCR 7-27 September 2012 

Exhibit 7.14 State Unit Cost Estimates for Review of Level 1 and Level 2 

Assessments under the 1989 TCR, RTCR, and Alternative Option (2007$) 

A B C=A*B D E=A*D F G=A*F

≤100 $ 39.22 1.0 $ 39.22 2.0 $ 78.44 2.0 $ 78.44

101-500 $ 39.22 1.0 $ 39.22 2.0 $ 78.44 2.0 $ 78.44

501-1,000 $ 39.22 2.0 $ 78.44 4.0 $ 156.87 4.0 $ 156.87

1,001-4,100 $ 39.22 2.0 $ 78.44 4.0 $ 156.87 4.0 $ 156.87

4,101-33,000 $ 39.22 3.0 $ 117.65 6.0 $ 235.31 6.0 $ 235.31

33,001-96,000 $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

96,001-500,000 $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

500,001-1 Million $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

> 1 Million $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

≤100 $ 39.22 1.0 $ 39.22 2.0 $ 78.44 2.0 $ 78.44

101-500 $ 39.22 1.0 $ 39.22 2.0 $ 78.44 2.0 $ 78.44

501-1,000 $ 39.22 2.0 $ 78.44 4.0 $ 156.87 4.0 $ 156.87

1,001-4,100 $ 39.22 2.0 $ 78.44 4.0 $ 156.87 4.0 $ 156.87

4,101-33,000 $ 39.22 3.0 $ 117.65 6.0 $ 235.31 6.0 $ 235.31

33,001-96,000 $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

96,001-500,000 $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

500,001-1 Million $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

> 1 Million $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

≤100 $ 39.22 1.0 $ 39.22 2.0 $ 78.44 2.0 $ 78.44

101-500 $ 39.22 1.0 $ 39.22 2.0 $ 78.44 2.0 $ 78.44

501-1,000 $ 39.22 2.0 $ 78.44 4.0 $ 156.87 4.0 $ 156.87

1,001-4,100 $ 39.22 2.0 $ 78.44 4.0 $ 156.87 4.0 $ 156.87

4,101-33,000 $ 39.22 3.0 $ 117.65 6.0 $ 235.31 6.0 $ 235.31

33,001-96,000 $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

96,001-500,000 $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

500,001-1 Million $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

> 1 Million $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

≤100 $ 39.22 1.0 $ 39.22 2.0 $ 78.44 2.0 $ 78.44

101-500 $ 39.22 1.0 $ 39.22 2.0 $ 78.44 2.0 $ 78.44

501-1,000 $ 39.22 2.0 $ 78.44 4.0 $ 156.87 4.0 $ 156.87

1,001-4,100 $ 39.22 2.0 $ 78.44 4.0 $ 156.87 4.0 $ 156.87

4,101-33,000 $ 39.22 3.0 $ 117.65 6.0 $ 235.31 6.0 $ 235.31

33,001-96,000 $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

96,001-500,000 $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

500,001-1 Million $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

> 1 Million $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

≤100 $ 39.22 1.0 $ 39.22 2.0 $ 78.44 2.0 $ 78.44

101-500 $ 39.22 1.0 $ 39.22 2.0 $ 78.44 2.0 $ 78.44

501-1,000 $ 39.22 2.0 $ 78.44 4.0 $ 156.87 4.0 $ 156.87

1,001-4,100 $ 39.22 2.0 $ 78.44 4.0 $ 156.87 4.0 $ 156.87

4,101-33,000 $ 39.22 3.0 $ 117.65 6.0 $ 235.31 6.0 $ 235.31

33,001-96,000 $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

96,001-500,000 $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

500,001-1 Million $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

> 1 Million $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

≤100 $ 39.22 1.0 $ 39.22 2.0 $ 78.44 2.0 $ 78.44

101-500 $ 39.22 1.0 $ 39.22 2.0 $ 78.44 2.0 $ 78.44

501-1,000 $ 39.22 2.0 $ 78.44 4.0 $ 156.87 4.0 $ 156.87

1,001-4,100 $ 39.22 2.0 $ 78.44 4.0 $ 156.87 4.0 $ 156.87

4,101-33,000 $ 39.22 3.0 $ 117.65 6.0 $ 235.31 6.0 $ 235.31

33,001-96,000 $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

96,001-500,000 $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

500,001-1 Million $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

> 1 Million $ 39.22 4.0 $ 156.87 8.0 $ 313.74 8.0 $ 313.74

Sources:

(A) Labor rates for state employee from Section 7.2.1.

(B), (D), (E) Labor hour assumptions based on best professional judgment.

Community Water Systems (CWSs) - GW

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

Unit Cost

Level 2 Triggers 

(triggered by 

multiple Level 1s) 

(hours) Unit Cost

Community Water Systems (CWSs) - SW

Transient Noncommunity Water Systems (TNCWSs) - GW

Transient Noncommunity Water Systems (TNCWSs) - SW

Labor Cost 

(per hour)

PWS Size

(Population

Served)

Level 1 Assessments Level 2 Assessments

Non-Acute 

Trigger 

(single trigger) 

(hours) Unit Cost

Acute 

Violations 

(hours)
Economic Analysis for the Final RTCR 7-28 September 2012 

Exhibit 7.15 Annualized PWS and State Cost Estimates for Level 1 and Level 2 

Assessments ($Millions, 2007$) 

PWSs State Total PWSs State Total

1989 TCR - Total $ 1.13 0.21$ $ 1.34 $ 1.08 $ 0.20 $ 1.29

RTCR - Total $ 1.63 0.20$ $ 1.84 $ 1.57 $ 0.20 $ 1.77

RTCR - Net Change $ 0.51 $ (0.01) $ 0.50 $ 0.49 $ (0.01) $ 0.48

Alternative Option - Total $ 1.76 0.23$ $ 1.99 $ 1.72 $ 0.23 $ 1.94

Alternative Option - Net Change $ 0.63 0.02$ $ 0.65 $ 0.63 $ 0.02 $ 0.65

1989 TCR - Total $ 0.70 0.26$ $ 0.96 $ 0.68 $ 0.25 $ 0.92

RTCR - Total $ 0.90 0.19$ $ 1.08 $ 0.88 $ 0.18 $ 1.06

RTCR - Net Change $ 0.20 $ (0.07) $ 0.12 $ 0.20 $ (0.07) $ 0.13

Alternative Option - Total $ 1.26 0.29$ $ 1.55 $ 1.30 $ 0.31 $ 1.61

Alternative Option - Net Change $ 0.55 0.03$ $ 0.58 $ 0.62 $ 0.06 $ 0.68

Note: Detail may not add due to independent rounding.

Source: Final RTCR Cost Model.

Level 2 Assessment

3% Discount Rate 7% Discount Rate

Level 1 Assessment

7.4.6 Corrective Actions 

PWSs 

Under the RTCR and Alternative option, all PWSs would be required to correct sanitary 

defects found through the performance of Level 1 or Level 2 assessments. For modeling 

purposes, EPA estimated only the net change in the number of corrective actions performed 

under the RTCR and Alternative option55 compared to the 1989 TCR. Based on discussions with 

state representatives, EPA estimates that additional corrective actions (on top of those already 

being performed under the 1989 TCR) would be performed for only 10% of the assessments 

undertaken as a result of the RTCR. Because only the net change in costs is estimated, no 

additional costs for corrective actions are modeled for the 1989 TCR (it is assumed that PWSs 

are already performing some corrective actions under the 1989 TCR). 

To estimate the costs incurred for the correction of sanitary defects, EPA estimated the 

percent distribution of PWSs that would perform different types of corrective actions as 

presented in the compliance forecast below (Exhibit 7.16a). The compliance forecast presented 

below focuses on the higher level categorization of corrective actions anticipated. The categories 

of anticipated corrective actions were informed by both EPA judgment and discussions of the 

TCRDSAC TWG and are essentially the same as those presented to the advisory committee. For 

each of the categories listed, a PWS is assumed to take a specific action that falls under that 

general category. Exhibit 7.16b lists the specific corrective actions that fall under the higher level 

categorization, along with the percent of PWSs estimated to perform that corrective action based 

on level 1 and level 2 assessments. Detailed compliance forecasts showing the specific corrective 

actions used in the cost analysis are provided in Appendix D, along with summary tables of the 

 

55 Any corrective actions based on a positive source water sample are assumed to be accounted for under the GWR 

and not under the RTCR. 
Economic Analysis for the Final RTCR 7-29 September 2012 

unit costs used in the analysis. Each corrective action in the detailed compliance forecast is also 

assigned a representative unit cost. Detailed descriptions of the derivation of unit costs are 

provided in Exhibits 5-1 through 5-47 of the Technology and Cost Document for the Final 

Revised Total Coliform Rule (USEPA, 2010d). 

As shown in the compliance forecast in Exhibit 7.16a, EPA estimates that corrective 

actions found through Level 1 assessments would result in corrective actions that focus more on 

actions by PWS staff such as flushing or training (columns A and B) than on permanent fixes to 

the PWS. This reflects the assumption that Level 1 assessments would generally be less involved 

than Level 2 assessments and may not result in finding more complex problems. Corrective 

actions taken as a result of Level 2 assessments are expected to find a higher proportion of 

structural/technical issues (columns C-K) resulting in material fixes to the PWSs and distribution 

system. Consistent with the discussions of the TCRDSAC regarding major structural fixes or 

replacements, EPA did not include these major costs in the analysis. Distribution system 

appurtenances such as storage tanks generally have a useful life that is accounted for in water 

system capital planning and the assessments conducted in response to RTCR triggers could 

identify when that useful life has ended but are not solely responsible for the need to correct the 

defect.56

It is not anticipated that the overall effectiveness of corrective actions will differ 

significantly by the type of corrective action. Some activities, such as spot flushing, may have a 

shorter, transient impact on water quality. However, most PWSs are expected to institute 

ongoing flushing programs that will have a continuing impact on water quality. Other corrective 

actions in the compliance forecast are expected to have ongoing benefits, though the exact 

duration may be highly variable depending on the exact conditions at the PWS. The overall 

duration of reduced occurrence modeled as a result of corrective actions initiated in response to 

either a Level 1 or Level 2 assessment is intended to reflect an average effectiveness of 

corrective actions. Uncertainties and associated sensitivity analyses that inform the effect of the 

reduced occurrence predicted from corrective actions are discussed further in Section 7.7. 

PWSs would also incur reporting and recordkeeping burden to notify the state upon 

completion of each corrective action. PWSs may also consult with the state or with outside 

parties to determine the appropriate corrective action to be implemented. PWS reporting and 

recordkeeping costs (including consultations) are derived by multiplying PWSs labor rates 

(Section 7.2.1) by an EPA-estimated labor burden. Exhibit 7.17 presents the estimated unit costs 

for this reporting and recordkeeping burden. 

 

56 Additionally, EPA ran two sensitivity analyses to assess the potential impacts of different distributions within the 

compliance forecast. Results of the sensitivity analyses are presented in Section 7.7, and indicate that the low bound 

estimates of annualized net change in costs at three percent discount rate are approximately $3M for the RTCR and 

$15M for the Alternative option, and the high bound estimates are approximately $25M for the RTCR and $40M for 

the Alternative option. Varying the assumptions about the percentage of corrective actions identified and the 

effectiveness of those actions had less than a linear effect on outcomes, and the RTCR continues to be less costly 

than the Alternative option under all scenarios modeled. 
Economic Analysis for the Final RTCR 7-30 September 2012 

States 

For each corrective action performed under the RTCR and Alternative option, states 

would incur recordkeeping and reporting burden to review and coordinate with PWSs. This 

includes burden incurred from any optional consultations states may conduct with PWSs or 

outside parties to determine the appropriate corrective action to be implemented. The state labor 

rate presented in Section 7.2.1 and estimates of labor hours are used to generate state unit 

corrective action costs. Exhibit 7.17 presents the estimated PWS and state reporting and 

recordkeeping unit costs (including consultations) by PWS size. 

Exhibit 7.16a Compliance Forecast for Corrective Actions based on Level 1 and 

Level 2 Assessments 

A B C D E F G H I J K

≤100 39% 15% 12% 9 % 8 % 6% 4% 1% 3% 1% 2 %

101-500 39% 15% 12% 9 % 8 % 6% 4% 1% 3% 1% 2 %

501-1,000 39% 15% 12% 9 % 8 % 6% 4% 1% 3% 1% 2 %

1,001-4,100 39% 15% 12% 9 % 8 % 6% 4% 1% 3% 1% 2 %

4,101-33,000 39% 15% 12% 9 % 8 % 6% 4% 1% 3% 1% 2 %

33,001-96,000 39% 15% 12% 9 % 8 % 6% 4% 1% 3% 1% 2 %

96,001-500,000 39% 15% 12% 9 % 8 % 6% 4% 1% 3% 1% 2 %

500,001-1 Million 39% 15% 12% 9 % 8 % 6% 4% 1% 3% 1% 2 %

> 1 Million 39% 15% 12% 9 % 8 % 6% 4% 1% 3% 1% 2 %

≤100 15% 4% 18% 15% 15% 11% 8% 2% 6% 2% 4 %

101-500 15% 4% 18% 15% 15% 11% 8% 2% 6% 2% 4 %

501-1,000 15% 4% 18% 15% 15% 11% 8% 2% 6% 2% 4 %

1,001-4,100 15% 4% 18% 15% 15% 11% 8% 2% 6% 2% 4 %

4,101-33,000 15% 4% 18% 15% 15% 11% 8% 2% 6% 2% 4 %

33,001-96,000 15% 4% 18% 15% 15% 11% 8% 2% 6% 2% 4 %

96,001-500,000 15% 4% 18% 15% 15% 11% 8% 2% 6% 2% 4 %

500,001-1 Million 15% 4% 18% 15% 15% 11% 8% 2% 6% 2% 4 %

> 1 Million 15% 4% 18% 15% 15% 11% 8% 2% 6% 2% 4 %

Source: (A) - (K) Percent of PWSs performing corrective actions based on Level 1 and Level 2 assessments reflect EPA estimate.

Addition or 

Upgrade of 

On-line 

Monitoring 

and Control

Booster 

Disinfection

Addition 

of 

Security 

Measures

Replace/Repair 

of Distribution 

System 

Components

PWS 

Flushing

Sampler 

Training

Storage 

Facility 

Maintenance

Maintenance 

of Adequate 

Pressure

Maintenance 

of 

appropriate 

Hydraulic 

Residence 

Level 2 Compliance Forecast

PWS Size

(Population

Served)

Crossconnection 

Control and 

Backflow 

Prevention 

Development 

and 

Implementation 

of an 

Operations Plan

Level 1 Compliance Forecast
Economic Analysis for the Final RTCR 7-31 September 2012 

Exhibit 7.16b Detailed PWS Compliance Forecast for Corrective Actions based on 

Level 1 and Level 2 Assessments 

Specific Corrective Action

Level 1 

Compliance 

Forecast

Level 2 

Compliance 

Forecast

Routine Flushing 30% 10%

Spot Flushing 9% 5%

Operator Training/Certification 15% 4%

Replace Valve 2% 3%

Installing a Dedicated Sampling Tap 2% 3%

Replace Iron Pipe 2% 3%

Replace Fittings 2% 3%

Replace Hydrant 2% 3%

Replace Meter 2% 3%

New Booster Pump Station 2% 3%

Modify/Replace Existing Pumps 2% 3%

Install Variable Frequency Drives 2% 3%

New Elevated Storage Tank 0% 0%

Install Surge Relief valve 2% 3%

Install Surge Control Tank 1% 3%

Install Auto Flushing Devices 2% 3%

Modify Inlet/Outlet Piping 1% 2%

Install Mixing Devices 1% 2%

Loop Dead Ends 1% 2%

Install Appropriate Main Sizes 1% 2%

Modify Storage Operation 1% 2%

Decommission Storage 1% 2%

Inspect & Clean Storage Tanks 2% 3%

Line Storage Tanks 1% 2%

Vent Repair/Replace Vent Screen 1% 2%

Repair/Replace Tank Hatch 1% 2%

Repair Storage Tank 1% 2%

Install Permanent Cl Booster Station 1% 2%

Install Temp Cl Booster Station 1% 2%

Install Permanent NH2Cl Booster Station 1% 2%

Install Temp NH2Cl Booster Station 1% 2%

Backflow Prevention Assembly 1% 2%

Online Cl Monitoring & Programming 1% 2%

Online NH2Cl Monitoring & Programming 1% 2%

Online Pressure Monitoring & Programming 1% 2%

Installation of Additional Security Measures 1% 2%

Develop/Implement/Maintain Operations 

Plan 1% 2%

Operator Training/Certification 1% 2%

Development and 

Implementation of an 

Operations Plan

General Corrective Action 

Category

Storage Facility Maintenance

Storage Facility Maintenance

Booster Disinfection

Cross-connection Control and 

Backflow Prevention Program

Addition or Upgrade of On-line 

Monitoring and Control

Addition of Security Measures

PWS Flushing

Replace/Repair of Distribution 

System Components

Maintenance of Adequate 

Pressure

Maintenance of Adequate 

Pressure

Sampler Training

Maintenance of appropriate 

Hydraulic Residence Time
Economic Analysis for the Final RTCR 7-32 September 2012 

Exhibit 7.17 Net Change in PWS and State Unit Costs Estimates for Reporting and 

Recordkeeping for Corrective Actions (2007$) 

A B C=A*B D E F=D*E

≤100 $ 25.10 0.5 $ 12.55 $ 39.22 0.5 $ 19.61

101-500 $ 27.03 0.5 $ 13.52 $ 39.22 0.5 $ 19.61

501-1,000 $ 28.96 0.5 $ 14.48 $ 39.22 0.5 $ 19.61

1,001-4,100 $ 29.73 0.5 $ 14.87 $ 39.22 0.5 $ 19.61

4,101-33,000 $ 36.00 0.5 $ 18.00 $ 39.22 0.5 $ 19.61

33,001-96,000 36.39 $ 0.5 $ 18.20 $ 39.22 0.5 $ 19.61

96,001-500,000 41.01 $ 0.5 $ 20.51 $ 39.22 0.5 $ 19.61

500,001-1 Million 41.01 $ 0.5 $ 20.51 $ 39.22 0.5 $ 19.61

> 1 Million $ 41.01 0.5 $ 20.51 $ 39.22 0.5 $ 19.61

Notes: 

Sources:

(A) Labor rates for PWSs from Exhibit 7.1.

(B) PWS labor hours for corrective action recordkeeping/reporting reflect EPA estimate.

(D) Labor rates for state employee from Section 7.2.1.

(E) State labor hours for corrective action recordkeeping/reporting reflect EPA estimate.

PWS Size

(Population

Served)

PWS and state burden estimates identical for all PWS types under 1989 TCR, RTCR, and Alternative Option.

Systems States

Labor Cost 

(per hour)

Corrective Action 

Burden (hours/ 

corrective action) Unit Cost

Labor Cost 

(per hour)

Corrective Action 

Burden (hours/ 

corrective action) Unit Cost

Corrective Action Net Cost Summary 

Annualized net cost estimates for PWSs and states to perform corrective actions are 

estimated by multiplying the number of Level 1 and Level 2 corrective actions estimated by the 

predictive model (i.e., 10 percent of Level 1 and Level 2 assessments representing the net 

increase in corrective actions found), by the percentages in the compliance forecast and unit 

costs of corrective actions and associated reporting and recordkeeping. Total and net change in 

annualized present value cost estimates for PWSs and states to perform corrective actions under 

the 1989 TCR, RTCR, and Alternative option are presented in Exhibit 7.18. 

Because only the net change in corrective actions taken is modeled, no costs are 

estimated under the 1989 TCR. The differences in the net change in corrective action costs 

between the RTCR and Alternative option are a function different number of assessments 

estimated to be performed in the predictive model as discussed in Section 7.4.5 above. 
Economic Analysis for the Final RTCR 7-33 September 2012 

Exhibit 7.18 Annualized PWS and State Cost Estimates for Corrective Actions 

based on Level 1 and Level 2 Assessments ($Millions, 2007$) 

PWSs State Total PWSs State Total

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total $ 9.62 0.01$ $ 9.63 $ 8.14 $ 0.01 $ 8.15

Alternative Option - Total $ 10.01 0.01$ $ 10.02 $ 8.52 $ 0.01 $ 8.53

RTCR - Net Change $ 9.62 0.01$ $ 9.63 $ 8.14 $ 0.01 $ 8.15

Alternative Option - Net Change 10.01 $ 0.01$ $ 10.02 $ 8.52 $ 0.01 $ 8.53

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total $ 2.82 0.00$ $ 2.82 $ 2.49 $ 0.00 $ 2.49

Alternative Option - Total $ 3.78 0.01$ $ 3.79 $ 3.57 $ 0.01 $ 3.58

RTCR - Net Change $ 2.82 0.00$ $ 2.82 $ 2.49 $ 0.00 $ 2.49

Alternative Option - Net Change $ 3.78 0.01$ $ 3.79 $ 3.57 $ 0.01 $ 3.58

Note: Detail may not add due to independent rounding.

Source: Final RTCR Cost Model.

Corrective Actions based on Level 2 Assessments

3% Discount Rate 7% Discount Rate

Corrective Actions based on Level 1 Assessments

7.4.7 Public Notification 

PWSs 

Tier 1 Public Notification 

Acute violations (E. coli MCL violations) would require Tier 1 PN under all regulatory 

options (1989 TCR, RTCR, and Alternative option). PWSs with acute violations must report the 

violation to the state by the end of the business day after the PWS learns of the violation and 

must notify the public within 24 hours. 

Tier 2 Public Notification 

PWSs with non-acute violations under the 1989 TCR must report the violation to the state 

by the end of the business day after the PWS learns of the violation, and must provide Tier 2 PN

within 30 days. PWSs with situations similar to 1989 TCR non-acute violations under the RTCR 

and Alternative option are not required to perform PN. These PWSs are required to perform Tier 

2 notification for a treatment technique violation (failure to perform Level 1 or 2 assessment if 

triggered; failure to correct all sanitary defects found), but because the cost model assumes full 

compliance with RTCR requirements, no cost is estimated for these violations. Overall, costs 

decrease significantly for Tier 2 PN under the Final Rule for both the RTCR and Alternative 

option. 

Tier 3 Public Notification 

Under the 1989 TCR, RTCR, and Alternative option, Tier 3 PN for monitoring and 

reporting violations are assumed to be reported once per year as part of the consumer confidence 

report (CCR). Because of the use of the CCR to communicate Tier 3 PN on a yearly basis, no 

cost differential between the 1989 TCR and the RTCR and Alternative option is estimated in the 

cost model. However, although they are not quantitatively evaluated as part of the EA, the 
Economic Analysis for the Final RTCR 7-34 September 2012 

TCRDSAC concluded that significant reductions in monitoring and reporting violations may be 

realized through the revised regulatory framework of the RTCR. See Section 7.6 for a discussion 

of non-quantified costs. 

Estimates of PWS unit costs for PN are derived by multiplying PWS labor rates from 

Section 7.2.1 and burden hour estimates derived from the Information Collection Request for the 

Public Water System Supervision Program (USEPA, 2008c). PWS PN unit cost estimates are 

presented in Exhibit 7.19. 
Economic Analysis for the Final RTCR 7-35 September 2012 

Exhibit 7.19 PWS Unit Cost Estimates for Public Notification (2007$) 

Labor Cost 

(per hour)

Average Number 

of Service 

Connections per 

System

Preparation 

(labor) (hours/

violation)

Distribution 

(labor)

(hours/

violation)

Distribution

(O&M Cost/

notice)

($/service

connection) Unit Cost

Preparation 

(labor) 

(hours/

violation)

Distribution 

(labor) (hours/

violation)

Distribution

(O&M Cost/notice) 

($/service

connection) Unit Cost

A B C D E F=A*(C+D)+(B*E) G H I J=A*(G+H)+(B*I)

≤100 25.10$ 440 8.5 12.0 0.05$ $ 536.55 3.5 9.0 $ 0.05 $ 335.75

101-500 27.03$ 387 8.5 12.0 0.05$ $ 573.44 3.5 9.0 $ 0.05 $ 357.20

501-1,000 28.96$ 303 8.5 12.0 -$ $ 593.68 3.5 30.0 $ 0.26 $ 1,049.05

1,001-4,100 29.73$ 850 8.5 12.0 -$ $ 609.47 3.5 30.0 $ 0.26 $ 1,216.99

4,101-33,000 36.00$ 4,288 9.2 12.0 -$ $ 763.66 3.5 30.0 $ 0.25 $ 2,259.65

33,001-96,000 36.39$ 17,273 10.0 12.0 -$ $ 800.58 3.5 30.0 $ 0.23 $ 5,191.88

96,001-500,000 41.01$ 56,465 10.0 12.0 -$ $ 902.22 3.5 30.0 $ 0.23 $ 14,360.67

500,001-1 Million 41.01$ 205,609 10.0 12.0 -$ $ 902.22 3.5 30.0 $ 0.23 $ 48,663.97

> 1 Million 41.01$ 448,564 10.0 12.0 -$ $ 902.22 3.5 30.0 $ 104,543.57 0.23 $ 

Community Water Systems (CWSs) - GW

≤100 25.10$ 4 1 8.5 12.0 0.05$ $ 516.62 3.5 9.0 $ 0.05 $ 315.82

101-500 27.03$ 9 9 8.5 12.0 0.05$ $ 559.05 3.5 9.0 $ 0.05 $ 342.81

501-1,000 28.96$ 315 8.5 12.0 -$ $ 593.68 3.5 30.0 $ 0.26 $ 1,052.07

1,001-4,100 29.73$ 756 8.5 12.0 -$ $ 609.47 3.5 30.0 $ 0.26 $ 1,192.61

4,101-33,000 36.00$ 3,495 9.0 12.0 -$ $ 757.48 3.5 30.0 $ 0.25 $ 2,076.93

33,001-96,000 36.39$ 16,366 10.0 12.0 -$ $ 800.58 3.5 30.0 $ 0.23 $ 4,983.17

96,001-500,000 41.01$ 50,564 10.0 12.0 -$ $ 902.22 3.5 30.0 $ 0.23 $ 13,003.50

500,001-1 Million 41.01$ 209,220 10.0 12.0 -$ $ 902.22 3.5 30.0 $ 0.23 $ 49,494.49

> 1 Million 41.01$ 473,641 10.0 12.0 -$ $ 902.22 3.5 30.0 $ 110,311.34 0.23 $ 

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

≤100 25.10$ 128 8.5 12.0 0.05$ $ 520.94 3.5 9.0 $ 0.05 $ 320.14

101-500 27.03$ 2 1 8.5 12.0 0.05$ $ 555.16 3.5 9.0 $ 0.05 $ 338.92

501-1,000 28.96$ 4 6 8.5 12.0 -$ $ 593.68 3.5 9.0 $ 0.05 $ 364.29

1,001-4,100 29.73$ 4 7 8.5 12.0 -$ $ 609.47 3.5 9.0 $ 0.05 $ 373.97

4,101-33,000 36.00$ 176 8.7 12.0 -$ $ 745.36 3.5 9.0 $ 0.05 $ 458.08

33,001-96,000 36.39$ 9 4 10.0 12.0 -$ $ 800.58 3.5 9.0 $ 0.02 $ 456.75

96,001-500,000 41.01$ 2,181 10.0 12.0 -$ $ 902.22 3.5 9.0 $ 0.02 $ 556.25

500,001-1 Million 41.01$ - 10.0 12.0 -$ $ 902.22 3.5 9.0 $ 0.02 $ 512.63

> 1 Million 41.01$ - 10.0 12.0 -$ $ 902.22 3.5 9.0 $ 0.02 $ 512.63

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

≤100 25.10$ 4 8.5 12.0 0.05$ $ 514.76 3.5 9.0 $ 0.05 $ 313.96

101-500 27.03$ 8 8.5 12.0 0.05$ $ 554.52 3.5 9.0 $ 0.05 $ 338.28

501-1,000 28.96$ 1 1 8.5 12.0 -$ $ 593.68 3.5 9.0 $ 0.05 $ 362.56

1,001-4,100 29.73$ 4 2 8.5 12.0 -$ $ 609.47 3.5 9.0 $ 0.05 $ 373.71

4,101-33,000 36.00$ 130 8.7 12.0 -$ $ 744.94 3.5 9.0 $ 0.05 $ 456.02

33,001-96,000 36.39$ 7 5 10.0 12.0 -$ $ 800.58 3.5 9.0 $ 0.02 $ 456.38

96,001-500,000 41.01$ - 10.0 12.0 -$ $ 902.22 3.5 9.0 $ 0.02 $ 512.63

500,001-1 Million 41.01$ - 10.0 12.0 -$ $ 902.22 3.5 9.0 $ 0.02 $ 512.63

> 1 Million 41.01$ - 10.0 12.0 -$ $ 902.22 3.5 9.0 $ 0.02 $ 512.63

Transient Noncommunity Water Systems (TNCWSs) - SW

≤100 25.10$ 9 8.5 12.0 0.05$ $ 514.99 3.5 9.0 $ 0.05 $ 314.19

101-500 27.03$ 3 0 8.5 12.0 0.05$ $ 555.62 3.5 9.0 $ 0.05 $ 339.38

501-1,000 28.96$ 4 9 8.5 12.0 -$ $ 593.68 3.5 9.0 $ 0.05 $ 364.45

1,001-4,100 29.73$ 5 8 8.5 12.0 -$ $ 609.47 3.5 9.0 $ 0.05 $ 374.50

4,101-33,000 36.00$ 5 7 8.8 12.0 -$ $ 747.00 3.5 9.0 $ 0.05 $ 452.55

33,001-96,000 36.39$ - 10.0 12.0 -$ $ 800.58 3.5 9.0 $ 0.02 $ 454.88

96,001-500,000 41.01$ - 10.0 12.0 -$ $ 902.22 3.5 9.0 $ 0.02 $ 512.63

500,001-1 Million 41.01$ - 10.0 12.0 -$ $ 902.22 3.5 9.0 $ 0.02 $ 512.63

> 1 Million 41.01$ 2 10.0 12.0 -$ $ 902.22 3.5 9.0 $ 0.02 $ 512.67

Transient Noncommunity Water Systems (TNCWSs) - GW

≤100 25.10$ 5 8.5 12.0 0.05$ $ 514.82 3.5 9.0 $ 0.05 $ 314.02

101-500 27.03$ 1 5 8.5 12.0 0.05$ $ 554.87 3.5 9.0 $ 0.05 $ 338.63

501-1,000 28.96$ 3 0 8.5 12.0 -$ $ 593.68 3.5 9.0 $ 0.05 $ 363.51

1,001-4,100 29.73$ 4 3 8.5 12.0 -$ $ 609.47 3.5 9.0 $ 0.05 $ 373.77

4,101-33,000 36.00$ 3 9 8.7 12.0 -$ $ 746.87 3.5 9.0 $ 0.05 $ 451.77

33,001-96,000 36.39$ 1 4 10.0 12.0 -$ $ 800.58 3.5 9.0 $ 0.02 $ 455.15

96,001-500,000 41.01$ 9 10.0 12.0 -$ $ 902.22 3.5 9.0 $ 0.02 $ 512.81

500,001-1 Million 41.01$ 1 10.0 12.0 -$ $ 902.22 3.5 9.0 $ 0.02 $ 512.65

> 1 Million 41.01$ - 10.0 12.0 -$ $ 902.22 3.5 9.0 $ 0.02 $ 512.63

(F), (J) used to derived 1989 TCR PN costs; (F) used to derive RTCR and Alternative Option PN costs. 

Sources:

(A) Labor rates for PWSs from Exhibit 7.1.

(B) SDWIS 2007 4th Quarter Freeze.

PWS Size

(Population

Served)

Tier 1 (acute) Tier 2 (non-acute)

Community Water Systems (CWSs) - SW

Notes: 

(E), (I) Distribution cost assumptions based on best professional judgment as carried forw ard from the original PN ICR.

(B) Service connections per system is consistent w ith SDWIS 2007 4th Quarter Freeze data. Data for certain size categories (e.g., <100, 101-500, 501-1,000) may seem counterintuitive. EPA is 

investigating the SDWIS database for any data discrepancies.

(C), (D), (G), (H) Labor hour assumptions based on best professional judgment as carried forw ard from the Information Collection Request for the Public Water System Supervision Program 

(USEPA, 2008c).
Economic Analysis for the Final RTCR 7-36 September 2012 

States 

Under the 1989 TCR, RTCR, and Alternative option, states would incur recordkeeping 

and reporting burden to provide consultation, review the PN certification, and file the report of 

the violation. State unit PN costs are based on the state labor rate presented in Section 7.2.1 and 

burden hour estimates derived from the Information Collection Request for the Public Water 

System Supervision Program (USEPA, 2008c). Estimates of state unit costs for PN are presented 

in Exhibit 7.20. 

Exhibit 7.20 State Unit Costs Estimates for Public Notification 

(1989 TCR, RTCR, Alternative Option) 

Labor Cost

(per hour)

Tier 1 

Consultation 

(labor) 

(hours/violation)

Tier 2 

Consultation 

(labor) 

(hours/violation)

Receive/Review 

PN Certification

(labor)

(hours/violation)

File Reports

(labor)

(hours/violation)

Tier 1

Unit Cost

Tier 2

Unit Cost

A B C D E F=A*(B+D+E) G=A*(C+D+E)

$ 39.22 3.0 1.1 0.2 0.1 $ 129.42 $ 54.91

Sources:

(A) Labor rate for state employee from Section 7.2.1.

(B), (C), (D), (E) Labor hour assumptions based on best professional judgment as carried forw ard from the Information Collection Request for 

the Public Water System Supervision Program (USEPA, 2008c).

Public Notification Net Cost Summary 

Total and net change in annualized present value costs for PN are estimated by 

multiplying the model estimates of PWSs with acute (Tier 1 PN) and non-acute (Tier 2 PN) 

violations by the PWS and state unit costs for performing PN activities. The RTCR Cost Model 

assumes that all violations are addressed following initial PN, and no burden would be incurred 

by PWSs or states for repeat notification. Exhibit 7.21 summarizes the total number of Tier 1 and 

Tier 2 PNs that would be prepared by PWS size and category for under the 1989 TCR, RTCR, 

and Alternative option over the entire 25-year period of analysis. Total and net change in 

annualized present value cost estimates for PWSs and states to perform PN under the 1989 TCR, 

RTCR, and Alternative option are presented in Exhibit 7.22. 

A significant reduction in costs is estimated due to the elimination of Tier 2 PN for TC 

occurrence (non-acute violations under the 1989 TCR) under the RTCR and Alternative option. 

Because state costs are calculated on a per-violation basis, state costs decline. Under the 

Alternative option, some of this cost decrease is offset by additional Tier 1 PN. 
Economic Analysis for the Final RTCR 7-37 September 2012 

Exhibit 7.21 Number of Tier 1 and Tier 2 Public Notifications over the 25-Year 

Compliance Period

RTCR

Alternative 

Option

A B C D

Community Water Systems (CWSs) - SW

≤100 157 709 100 100

101-500 167 760 119 119

501-1,000 102 424 75 75

1,001-4,100 162 1,103 146 146

4,101-33,000 197 2,152 197 197

33,001-96,000 56 534 56 56

96,001-500,000 24 233 24 24

500,001-1 Million - 22 - -

> 1 Million - - - -

Total 865 5,936 717 717

≤100 1,141 15,155 853 926

101-500 1,025 12,383 696 747

501-1,000 284 3,300 188 203

1,001-4,100 477 6,354 342 342

4,101-33,000 263 4,545 263 263

33,001-96,000 53 656 53 53

96,001-500,000 10 129 10 10

500,001-1 Million - - - -

> 1 Million - - - -

Total 3,253 42,521 2,405 2,544

≤100 35 175 28 28

101-500 29 128 19 19

501-1,000 9 42 6 6

1,001-4,100 19 79 13 13

4,101-33,000 - 5 - -

33,001-96,000 - - - -

96,001-500,000 - - - -

500,001-1 Million - - - -

> 1 Million - - - -

Total 93 429 67 67

≤100 856 9,411 559 723

101-500 447 4,402 315 446

501-1,000 95 1,042 79 99

1,001-4,100 169 1,792 114 114

4,101-33,000 9 123 9 9

33,001-96,000 - 4 - -

96,001-500,000 - - - -

500,001-1 Million - - - -

> 1 Million - - - -

Total 1,577 16,774 1,077 1,393

≤100 430 1,872 250 250

101-500 170 729 90 90

501-1,000 28 115 17 17

1,001-4,100 50 220 29 29

4,101-33,000 - 8 - -

33,001-96,000 - - - -

96,001-500,000 - - - -

500,001-1 Million - - - -

> 1 Million - - - -

Total 677 2,945 386 386

≤100 6,649 70,156 5,477 7,796

101-500 2,089 23,394 1,608 2,441

501-1,000 221 2,373 177 230

1,001-4,100 186 2,065 117 117

4,101-33,000 4 116 4 4

33,001-96,000 - - - -

96,001-500,000 - - - -

500,001-1 Million - - - -

> 1 Million - - - -

Total 9,149 98,104 7,383 10,589

Grand Total 15,613 166,709 12,035 15,695

Note: Detail may not add due to rounding.

Sources:

(A), (B) - A.1.z

(C) - A.2.z

(D) - A.3.z

1989 TCR

PWS Size

(Population

Served)

Tier 1 PN

Community Water Systems (CWSs) - GW

Transient Noncommunity Water Systems (TNCWSs) - GW

Nontransient Noncommunity Water Systems (NTNCWSs) - SW

Nontransient Noncommunity Water Systems (NTNCWSs) - GW

Transient Noncommunity Water Systems (TNCWSs) - SW

Tier 1 PN Tier 2 PN Tier 1 PN
Economic Analysis for the Final RTCR 7-38 September 2012 

Exhibit 7.22 Annualized PWS and State Cost Estimates for Public Notification 

($Millions, 2007$)

PWSs State Total PWSs State Total

1989 TCR - Total $ 3.75 0.44$ $ 4.19 $ 3.60 $ 0.42 $ 4.02

RTCR - Total $ 0.26 0.06$ $ 0.32 $ 0.25 $ 0.06 $ 0.31

RTCR - Net Change $ (3.49) $ (0.38) $ (3.86) $ (3.35) $ (0.36) $ (3.71)

RTCR - Percent Change -93% -86% -92% -93% -86% -92%

Alternative Option - Total $ 0.35 0.08$ $ 0.43 $ 0.35 $ 0.08 $ 0.44

Alternative Option - Net Change $ (3.40) $ (0.36) $ (3.76) $ (3.25) $ (0.34) $ (3.58)

Alternative Option - Percent Change -91% -81% -90% -90% -80% -89%

Note: Detail may not add due to independent rounding.

Source: Final RTCR Cost Model.

3% Discount Rate 7% Discount Rate

7.4.8 Uncertainty in Unit Costs 

As stated in Section 7.2.5, EPA recognizes that there are both variability and uncertainty 

in unit cost estimates used to develop national costs for the RTCR. Variability is expected in the 

actual costs that would be experienced by different PWSs of similar size conducting the same 

corrective action. Otherwise similar PWSs may experience different capital and/or O&M costs 

due to site-specific factors. Inputs to unit costs such as water quality conditions, labor rates, and 

land costs can be highly variable and increase the system-to-system variability in unit costs. In 

developing the unit cost estimates, there is insufficient information to fully characterize what the 

distribution of this variability would be on a national scale; therefore, EPA uses mean values for 

these input parameters. 

The unit costs used in this EA are developed as average or representative estimates of 

what these unit costs would be nationally, and are not the unit costs of any particular PWS. Some 

components of monitoring costs, such as the purchase and wear-and-tear of vehicles, are not 

quantified because of either limited data or inability to attribute these costs directly to the RTCR. 

Additionally, the PWS and state labor hours for each rule component (specifically for Level 1 

and Level 2 assessments) are meant to capture national averages for the purposes of developing 

national cost estimates and making comparisons between regulatory options. Thus, the unit costs 

presented in this document may over- or underestimate the unit costs of any particular PWS. 

Detailed information on the derivation of unit costs for each rule component is provided in the 

Technology and Cost Document for the Final Revised Total Coliform Rule (USEPA, 2010d).

7.5 Household Costs 

The household cost analysis considers the impact that the costs incurred by CWSs have 

on the households they serve. This analysis considers the potential increase in a household’s 

annual water bill if a CWS passed the entire cost increase resulting from the rule on to their 

customers. This analysis is a tool to gauge potential impacts and should not be construed as a 

precise estimate of potential changes to household water bills. State costs and costs to TNCWSs 

and NTNCWSs are not included in this analysis since their costs are not typically passed through 

directly to households. 
Economic Analysis for the Final RTCR 7-39 September 2012

To calculate household costs (which are in the units of $ per household per year), the 

CWS population subject to the RTCR by PWS size is divided by the average number of people 

per household, estimated as 2.56 for the year 2007 (United States Census Bureau, 2008), to 

calculate the number of households subject to the RTCR by PWS size. The cost of the rule, by 

size category, is then divided by that number of households to determine a per-household cost. 

The first section of Exhibit 7.23 presents net costs per household under the RTCR and 

Alternative option for all rule components spread across all CWSs. In this scenario, comparison 

to the 1989 TCR shows a cost savings for households in the largest size category. For those 

households that are expected to see a cost increase, the average annual water bill would be 

expected to increase by less than ten cents on average. Although this average cost per household 

is very low, customers served by PWSs that incur greater costs to comply with the RTCR would 

be higher.

While the average increase in annual household water bills to implement the RTCR is 

less than a dollar, customers served by a small CWS that have to take corrective actions as a 

result of the rule would incur slightly larger increases in their water bills. The subsequent 

sections of the exhibit present net costs per household for different subsections of CWSs (e.g., 

CWSs that perform assessments but no corrective actions, CWSs that do perform corrective 

actions, and CWSs that do not perform assessments or corrective actions). As shown in the 

second section of Exhibit 7.23, approximately 67% of households belong to CWSs that would 

perform assessments but would not perform corrective actions (because no sanitary defects are 

found). These households would experience a slight cost savings on an annual basis, due to a 

slight reduction in monitoring and PN costs. The 9% of households belonging to CWSs that 

would perform corrective actions would experience an increase in annual net household costs of 

less than $1 to approximately $26 on an annual basis. The final section of the exhibit presents the 

24% of households belonging to CWSs that would not perform assessments or corrective actions. 

Households of this category would experience an increase in cost savings when compared to 

those performing corrective actions, and a decrease in cost savings when compared to those 

performing assessments but no corrective actions. This decrease in costs savings is because no 

PN costs are associated with systems not performing assessments. Overall, the main driver of 

additional household costs under the RTCR is whether or not additional corrective actions are 

performed.
Economic Analysis for the Final RTCR 7-40 September 2012 

Exhibit 7.23 Summary of Net Annual Per-Household Costs for the RTCR (2007$) 

RTCR Net

RTCR Net Cost per 

Household

Alternative 

Option Net

Alternative 

Option Net 

Cost per 

Household RTCR Net

RTCR Net 

Cost per 

Household

Alternative 

Option Net

Alternative 

Option Net 

Cost per 

Household

A B C D=C/A E F=E/B G H=G/A I J=I/B

≤100 307,243 307,243 $ 111,694 $ 0.364 $ 225,693 $ 0.735 $ 207,140 0.674$ $ 348,782 $ 1.135

101-500 1,589,510 1,589,510 $ 371,004 $ 0.233 $ 464,207 $ 0.292 $ 471,664 0.297$ $ 598,244 $ 0.376

501-1,000 1,624,853 1,624,853 $ 46,687 $ 0.029 $ 87,294 $ 0.054 $ 96,473 0.059$ $ 148,274 $ 0.091

1,001-4,100 7,816,592 7,816,592 $ 371,294 $ 0.048 $ 371,294 $ 0.048 $ 418,935 0.054$ $ 418,935 $ 0.054

4,101-33,000 27,997,647 27,997,647 $ 2,385,056 $ 2,385,056 0.085 $ $ 2,083,266 0.085 $ 0.074$ 2,083,266 $ $ 0.074

33,001-96,000 21,933,438 21,933,438 $ 1,532,410 $ 1,532,410 0.070 $ $ 1,273,202 0.070 $ 0.058$ 1,273,202 $ $ 0.058

96,001-500,000 26,770,609 26,770,609 $ 1,479,280 $ 1,479,280 0.055 $ $ 1,214,316 0.055 $ 0.045$ 1,214,316 $ $ 0.045

500,001-1 Million 9,764,979 9,764,979 $ 157,138 $ 0.016 $ 157,138 $ 0.016 $ 125,671 0.013$ $ 125,671 $ 0.013

> 1 Million 16,309,853 16,309,853 $ (2,223) $ (0.000) $ (2,223) $ (0.000) $ (1,479) (0.000)$ $ (1,479) $ (0.000)

Total 114,114,724 114,114,724 $ 6,452,342 $ 6,700,151 0.057 $ $ 5,889,190 0.059 $ 0.052$ 6,209,211 $ $ 0.054

≤100 125,340 124,920 $ (185,923) $ (1.483) $ (149,283) $ (1.195) $ (125,037) (0.998)$ $ (75,885) $ (0.607)

101-500 460,577 464,568 $ (137,193) $ (0.298) $ (103,168) $ (0.222) $ (82,657) (0.179)$ $ (40,057) $ (0.086)

501-1,000 394,643 401,009 $ (133,453) $ (0.338) $ (123,890) $ (0.309) $ (111,147) (0.282)$ $ (98,598) $ (0.246)

1,001-4,100 2,341,578 2,341,578 $ (262,222) $ (0.112) $ (262,222) $ (0.112) $ (213,247) (0.091)$ $ (213,247) $ (0.091)

4,101-33,000 24,827,588 24,827,588 $ (195,108) $ (0.008) $ (195,108) $ (0.008) $ (76,420) (0.003)$ $ (76,420) $ (0.003)

33,001-96,000 19,232,570 19,232,570 $ (173,238) $ (0.009) $ (173,238) $ (0.009) $ (142,573) (0.007)$ $ (142,573) $ (0.007)

96,001-500,000 23,912,325 23,912,325 $ (146,682) $ (0.006) $ (146,682) $ (0.006) $ (131,967) (0.006)$ $ (131,967) $ (0.006)

500,001-1 Million 5,524,188 5,524,188 $ (40,160) $ (0.007) $ (40,160) $ (0.007) $ (36,993) (0.007)$ $ (36,993) $ (0.007)

> 1 Million - - $ - $ - $ - $ - $ - $ - $ - $ - 

Total 76,818,809 76,828,746 $ (1,273,980) $ (1,193,752) (0.017) $ $ (0.016) $ (920,040) (0.012)$ $ (815,739) $ (0.011)

≤100 13,927 13,880 $ 365,576 $ 26.250 $ 388,703 $ 28.004 $ 330,235 23.712$ $ 353,002 $ 25.432

101-500 51,175 51,619 $ 516,102 $ 10.085 $ 508,146 $ 9.844 $ 452,342 8.839$ $ 450,070 $ 8.719

501-1,000 43,849 44,557 $ 178,205 $ 4.064 $ 181,189 $ 4.066 $ 155,596 3.548$ $ 158,538 $ 3.558

1,001-4,100 260,175 260,175 $ 590,719 $ 2.270 $ 590,719 $ 2.270 $ 512,568 1.970$ $ 512,568 $ 1.970

4,101-33,000 3,170,059 3,170,059 $ 2,605,551 $ 2,605,551 0.822 $ $ 2,198,499 0.822 $ 0.694$ 2,198,499 $ $ 0.694

33,001-96,000 2,700,868 2,700,868 $ 1,709,801 $ 1,709,801 0.633 $ $ 1,424,758 0.633 $ 0.528$ 1,424,758 $ $ 0.528

96,001-500,000 2,858,284 2,858,284 $ 1,625,742 $ 1,625,742 0.569 $ $ 1,346,704 0.569 $ 0.471$ 1,346,704 $ $ 0.471

500,001-1 Million 613,799 613,799 $ 195,076 $ 0.318 $ 195,076 $ 0.318 $ 161,185 0.263$ $ 161,185 $ 0.263

> 1 Million - - -$ $ - -$ -$ -$ -$ -$ -$ 

Total 9,712,136 9,713,240 $ 7,786,773 $ 7,804,928 0.802 $ $ 6,581,888 0.804 $ 0.678$ 6,605,324 $ $ 0.680

≤100 167,976 168,442 (67,959) $ (0.405) (13,728) $ (0.081) 1,943 0.012$ 71,665 $ 0.425

101-500 1,077,758 1,073,324 (7,905) $ (0.007) 59,230 $ 0.055 101,979 0.095$ 188,231 $ 0.175

501-1,000 1,186,361 1,179,288 1,936 $ 0.002 29,995 $ 0.025 52,024 0.044$ 88,334 $ 0.075

1,001-4,100 5,214,839 5,214,839 42,797 $ 0.008 42,797 $ 0.008 119,614 0.023$ 119,614 $ 0.023

4,101-33,000 - - - $ - - -$ - -$ - -$ 

33,001-96,000 - - - $ - - -$ - -$ - -$ 

96,001-500,000 - - - $ - - -$ - -$ - -$ 

500,001-1 Million 3,626,992 3,626,992 - $ - - -$ - -$ - -$ 

> 1 Million 16,309,853 16,309,853 - $ - - -$ - -$ - -$ 

Total 27,583,779 27,572,738 $ (31,132) $ (0.001) $ 118,294 $ 0.004 $ 275,560 0.010$ $ 467,844 $ 0.017

Source:

(C), (E), (G), (I) Exhibit 7.28.

Community Water Systems (CWSs) performing Level 1/Level 2 Assessments (and no Corrective Actions)

Community Water Systems (CWSs) performing Corrective Actions

7% Discount Rate

PWS Size

(Population

Served)

3% Discount Rate

Number of 

Households 

(Alternative Option)

Community Water Systems (CWSs) not performing Level 1/Level 2 Assessments, or Corrective Actions

Number of 

Households 

(RTCR)

All Community Water Systems (CWSs)
Economic Analysis for the Final RTCR 7-41 September 2012

7.6 Non-quantified Costs

EPA believes that all of the rule elements that are the major drivers of the net changes in 

costs of the 1989 TCR have been quantified to the greatest degree possible. However, cost 

reductions related to fewer possible monitoring and reporting violations are not specifically 

accounted for in the cost analysis, and their exclusion from consideration may result in an 

overestimate of net change in cost between the 1989 TCR and the RTCR or Alternative option.

In addition, under the 1989 TCR, RTCR, and Alternative option, Tier 3 PN for 

monitoring and reporting violations are assumed to be reported once per year as part of the CCR. 

Because of the use of the CCR to communicate Tier 3 PN on a yearly basis, no cost differential 

between the 1989 TCR and the RTCR and Alternative option is estimated in the cost model. 

However, the advisory committee concluded that significant reductions in monitoring and 

reporting violations may be realized through the revised regulatory framework of the RTCR. 

These possible reductions have not been quantified. System resources used to process monitoring 

violation notices for the CCR and respond to customer inquiries about the notices as well as state 

resources to remind systems to take samples, may be reduced if significant reductions are 

realized. Exclusion of this potential cost savings may lead to an underestimate of the PN cost 

savings under both the RTCR and Alternative option. 

Additionally, as an underlying assumption to the costing methodology, EPA has assumed 

that all PWSs subject to the RTCR requirements are already complying with the 1989 TCR. 

There may be some PWSs that are not in full compliance with the 1989 TCR, and if so,

additional costs would be incurred. 

7.7 Uncertainty Analysis

There are two primary sources of uncertainty in the RTCR cost modeling. The first is 

related to the underlying estimates of events resulting from the rule revisions as generated from 

the occurrence and predictive modeling. The occurrence and predictive modeling (discussed in 

detail in Chapter 5) does not explicitly consider uncertainty, and therefore does not generate 

confidence intervals on the predicted outcomes. However, EPA evaluated the model inputs to 

determine which of the inputs were likely to have a significant effect on the results and subjected 

those to further review through sensitivity analyses. In particular, EPA evaluated the impacts of 

alternative estimates of the net change percentage of PWSs predicted to take corrective actions in 

response to an assessment (10 percent in the model) and the associated effectiveness of those 

corrective actions (Section 5.3.3.1 discusses these analyses in detail). The results of these 

analyses suggest that changes in the major assumptions about the net change percentage of 

corrective actions identified and the effectiveness of those actions have a less than linear effect 

on predicted outcomes. When applied to costs estimates they have even less impact.

In the case where PWSs increase the percentage of corrective actions taken in response to 

an assessment, costs are expected to increase corresponding to the greater number of corrective 

actions taken. Using the increases predicted for the small subset of PWSs analyzed, it is 

estimated that corrective actions (and related costs) would increase by 65% for Level 1 

corrective actions and 7% for Level 2 corrective actions. This is in response to a doubling of the 

net change percentage of corrective actions taken in response to an assessment. However, the 
Economic Analysis for the Final RTCR 7-42 September 2012

increased effectiveness of more corrective actions has a dampening effect on other costs that 

would offset the increased corrective action costs. For instance, although the numbers of 

corrective actions increase due to the higher percentages found during assessments, the actual 

number of assessments decreases by 16% for Level 1 and by 43% for Level 2 because fewer 

positive samples (ranging from a 14% decrease in routine TC+ to a 28% decrease in repeat TC+) 

are predicted to be found. The overall effect of the cost increases and decreases in response to the 

major predictive occurrence model uncertainties is expected to be minimal.

The other major area of uncertainty that may affect the resulting cost calculations is the 

distribution of corrective actions taken by PWSs (the compliance forecast) in response to finding 

a problem during a Level 1 or Level 2 assessment. The compliance forecast presented in Exhibits

7.16a and 7.16b represents EPA’s best estimate of a distribution of corrective actions that may be 

taken by PWSs to respond to problems identified under the RTCR. Because there is a wide 

variation in the unit costs of the actual corrective actions underlying the compliance forecast (see 

Appendix D for unit cost detail), EPA ran two sensitivity analyses to assess the potential impacts 

of different distributions within the compliance forecast. These two sensitivity runs attempt to 

bound the analysis of corrective action costs by generating a low and high cost bound to the 

estimates.

Low Bound Estimate

During discussions in the TCRDSAC meetings, several stakeholders suggested that 

almost all additional corrective actions taken in response to the RTCR would be in response to 

transient contamination events or poor sampling techniques. These are also the least expensive 

corrective actions. To examine the effects of greater emphasis on these types of corrective 

actions, EPA reran the cost model to reflect 90% selection of either spot flushing or sampler 

training as corrective actions. The remaining 10% of costs were distributed across the least costly 

corrective actions under each of the other compliance forecast categories. This results in an 

approximate 81 percent decrease in total net costs for the RTCR and an approximate 43 percent 

decrease in total net costs for the Alternative option, using a 3 percent discount rate. Exhibit 7.24 

shows the change in the overall costs with this change.

High Bound Estimate

PWSs may also take actions that result in higher corrective action costs than those 

predicted by the current compliance forecast, although this would be a less likely scenario based 

on stakeholder discussions. Purely economic considerations also suggest that, given the option, 

PWSs would opt for the least costly option to address any issues identified. However, to test a 

potential high end of corrective action costs, EPA ran the cost model with the compliance 

forecast set to take the highest cost corrective action in each compliance forecast category. In this 

scenario, only 5% of corrective actions were predicted for flushing and sampler training, and 

10% were estimated for each of the other compliance categories, and unit costs were assigned for 

the highest unit cost corrective action in each. This results in an increase in total net costs for the 

RTCR by approximately a factor of 1.8, and an increase in total net costs by approximately a 

factor of 1.5 for the Alternative option. Exhibit 7.24 shows the annualized total and net change 

cost estimates for PWSs and states to comply with RTCR under the 1989 TCR, RTCR, and 

Alternative options based on low bound and high bound estimates in the compliance forecast.
Economic Analysis for the Final RTCR 7-43 September 2012 

Exhibit 7.24 Sensitivity Analysis—Annualized Net Change in Costs based on 

Changes in Compliance Forecast ($Millions, 2007$) 

PWSs State Total PWSs State Total

RTCR Net Change $ 14.15 0.15$ $ 14.30 $ 13.75 $ 0.42 $ 14.17

RTCR Low Bound Net Change $ 2.61 0.15$ $ 2.75 $ 3.91 $ 0.42 $ 4.33

RTCR High Bound Net Change $ 25.10 0.15$ $ 25.25 $ 23.63 $ 0.42 $ 24.05

Alternative Option Net Change $ 29.29 0.31$ $ 29.60 $ 31.09 $ 0.61 $ 31.69

Alternative Option Low Bound Net Change $ 16.54 0.31$ $ 16.84 $ 19.93 $ 0.61 $ 20.54

Alternative Option High Bound Net Change $ 42.68 0.31$ $ 42.99 $ 43.63 $ 0.61 $ 44.24

Note: Detail may not add due to independent rounding.

Source: Final RTCR Cost Model.

3% Discount Rate 7% Discount Rate

Overall, EPA recognizes that there is uncertainty in various parts of its estimates that 

could result in either an over- or underestimate of the costs as presented in this chapter. Exhibit 

7.25 presents a summary of these issues, references the location in the EA where the information 

is introduced, and estimates the effects that each may have on national costs. All of the 

assumptions influencing the EA baseline (1989 TCR) do so in the same way for the RTCR and 

Alternative option. Therefore, EPA does not expect the net results of the analyses presented in 

this EA to be significantly influenced by the uncertainty in the assumptions applied in 

developing the RTCR cost analysis. EPA has been careful to use the best available data, to 

account for uncertainty quantitatively when possible, and to avoid any consistent biases in 

assumptions and the use of data. 
Economic Analysis for the Final RTCR 7-44 September 2012 

Exhibit 7.25 Cost Uncertainty Summary 

Uncertainty

Section with Full

Discussion of 

Uncertainty

Most Likely Effect of Current Assumptions on Estimate 

of National Costs

Underestimate Overestimate Unknown Impact

Labor Rate 7.2.1 No No X

Labor Burden 

Estimates

7.4.1–7.4.8 No No X

Unit Costs 7.4.1–7.4.8 No No X [note 1]

Percentage of 

systems on monthly, 

quarterly, and annual 

monitoring 

frequencies

7.4.3 No No X

Number of acute 

violations

7.4.5 No No X

Number of systems 

performing level 1 and 

level 2 assessments

7.4.5 No No X

Compliance forecasts 

for corrective actions 

based on level 1 and 

level 2 assessments

7.4.6 and 7.7 No No X [note 2]

Corrective Actions 

based on level 1 and 

level 2 Assessments

7.4.6 and 7.7 No No X

Notes: 

1) All unit costs (with the exception of those for corrective actions, which are not applied to the 1989 TCR) were 

used in the RTCR cost code in the same way for the 1989 TCR, RTCR, and Alternative option. Therefore, EPA 

expects that any under- or over-estimation would affect the baseline and other options similarly, resulting in no 

significant net effect on the results of the analysis. 

2) The compliance forecast represents EPA’s best estimate of a distribution of corrective actions that may be 

taken by PWSs to respond to problems identified under the RTCR. EPA ran two sensitivity analyses to assess 

the potential impacts of different distributions within the compliance forecast (see Section 7.7). These two 

sensitivity runs showed that under the low bound and high bound estimates, the net change costs for the RTCR 

were smaller than those for the Alternative option. 
Economic Analysis for the Final RTCR 7-45 September 2012 

7.8 Comparison of Total and Net Annualized Costs for All Regulatory Options 

Based on information presented previously in this chapter, EPA developed national cost 

estimates for the 1989 TCR, RTCR, and Alternative option. Exhibit 7.26 presents the total57 and 

net change in annualized costs to PWSs and states at 3 and 7 percent discount rates. Exhibit 7.27 

presents the total and net change in annualized costs for the 1989 TCR, RTCR, and Alternative 

option by rule component at 3 and 7 percent discount rates. Exhibit 7.28 presents the total and 

net change in annualized costs for the 1989 TCR, RTCR, and Alternative option by PWS size 

and type at 3 and 7 percent discount rates. Exhibit 7.29 presents the costs shown in Exhibit 7.28 

on a per-PWS basis. Further discussion of the results follows these exhibits. 

Exhibit 7.26 Comparison of Total and Net Change from 1989 TCR in Annualized 

Present Value Costs ($Millions, 2007$) 

PWSs State Total PWSs State Total

1989 TCR - Total $ 185 0.9$ $ 186 $ 178 $ 0.9 $ 179

RTCR - Total $ 199 1.1$ $ 200 $ 192 $ 1.3 $ 193

RTCR - Net Change $ 1 4 0.1$ $ 1 4 $ 1 4 $ 0.4 $ 1 4

RTCR - Percent Change 8% 16% 8% 8% 48% 8%

Alternative Option - Total $ 214 1.2$ $ 216 $ 209 $ 1.5 $ 210

Alternative Option - Net Change $ 2 9 0.3$ $ 3 0 $ 3 1 $ 0.6 $ 3 2

Alternative Option - Percent Change 16% 34% 16% 17% 69% 18%

Source: Final RTCR cost model.

Note: Detail may not add due to independent rounding. Because only the net change in costs of some rule components are considered as 

part of the cost analysis, references to “total” costs in this exhibit do not refer to the complete costs for regulatory implementation, but 

only to the specific costs considered to calculate net changes in costs. 

3% Discount Rate 7% Discount Rate

 

57 Because only the net change in costs of some rule components are considered as part of the cost analysis, 

references to total costs in this section do not refer to the complete costs for regulatory implementation, but only to 

the specific costs considered to calculate net changes in costs. 
Economic Analysis for the Final RTCR 7-46 September 2012 

Exhibit 7.27 Comparison of Total and Net Change in Annualized Present Value 

Costs by Rule Component ($Millions, 2007$) 

PWSs State Total PWSs State Total

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total $ 2.77 0.18$ $ 2.95 $ 4.00 $ 0.26 $ 4.26

RTCR - Net Change $ 2.77 0.18$ $ 2.95 $ 4.00 $ 0.26 $ 4.26

Alternative Option - Total $ 2.77 0.18$ $ 2.95 $ 4.00 $ 0.26 $ 4.26

Alternative Option - Net Change $ 2.77 0.18$ $ 2.95 $ 4.00 $ 0.26 $ 4.26

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total $ 0.59 0.42$ $ 1.01 $ 0.84 $ 0.59 $ 1.42

RTCR - Net Change $ 0.59 0.42$ $ 1.01 $ 0.84 $ 0.59 $ 1.42

Alternative Option - Total $ 0.59 0.42$ $ 1.01 $ 0.84 $ 0.59 $ 1.42

Alternative Option - Net Change $ 0.59 0.42$ $ 1.01 $ 0.84 $ 0.59 $ 1.42

1989 TCR - Total $ 170.59 -$ 170.59 $ $ 163.94 -$ 163.94 $ 

RTCR - Total $ 174.71 -$ 174.71 $ $ 167.74 -$ 167.74 $ 

RTCR - Net Change $ 4.12 -$ $ 4.12 $ 3.80 -$ $ 3.80

Alternative Option - Total $ 187.50 -$ 187.50 $ $ 182.48 -$ 182.48 $ 

Alternative Option - Net Change $ 16.91 -$ $ 16.91 $ 18.54 -$ $ 18.54

1989 TCR - Total $ 3.87 -$ $ 3.87 $ 3.72 -$ $ 3.72

RTCR - Total $ 1.12 -$ $ 1.12 $ 1.09 -$ $ 1.09

RTCR - Net Change $ (2.75) -$ $ (2.75) $ (2.63) -$ $ (2.63)

Alternative Option - Total $ 0.78 -$ $ 0.78 $ 0.66 -$ $ 0.66

Alternative Option - Net Change $ (3.10) -$ $ (3.10) $ (3.06) -$ $ (3.06)

1989 TCR - Total $ 5.11 -$ $ 5.11 $ 4.92 -$ $ 4.92

RTCR - Total $ 4.88 -$ $ 4.88 $ 4.70 -$ $ 4.70

RTCR - Net Change $ (0.23) -$ $ (0.23) $ (0.22) -$ $ (0.22)

Alternative Option - Total $ 5.66 -$ $ 5.66 $ 5.59 -$ $ 5.59

Alternative Option - Net Change $ 0.54 -$ $ 0.54 $ 0.67 -$ $ 0.67

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Net Change -$ -$ -$ -$ -$ -$ 

Alternative Option - Total -$ -$ -$ -$ -$ -$ 

Alternative Option - Net Change -$ -$ -$ -$ -$ -$ 

1989 TCR - Total $ 1.13 0.21$ $ 1.34 $ 1.08 $ 0.20 $ 1.29

RTCR - Total $ 1.63 0.20$ $ 1.84 $ 1.57 $ 0.20 $ 1.77

RTCR - Net Change $ 0.51 $ (0.01) $ 0.50 $ 0.49 $ (0.01) $ 0.48

Alternative Option - Total $ 1.76 0.23$ $ 1.99 $ 1.72 $ 0.23 $ 1.94

Alternative Option - Net Change $ 0.63 0.02$ $ 0.65 $ 0.63 $ 0.02 $ 0.65

1989 TCR - Total $ 0.70 0.26$ $ 0.96 $ 0.68 $ 0.25 $ 0.92

RTCR - Total $ 0.90 0.19$ $ 1.08 $ 0.88 $ 0.18 $ 1.06

RTCR - Net Change $ 0.20 $ (0.07) $ 0.12 $ 0.20 $ (0.07) $ 0.13

Alternative Option - Total $ 1.26 0.29$ $ 1.55 $ 1.30 $ 0.31 $ 1.61

Alternative Option - Net Change $ 0.55 0.03$ $ 0.58 $ 0.62 $ 0.06 $ 0.68

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total $ 9.62 0.01$ $ 9.63 $ 8.14 $ 0.01 $ 8.15

RTCR - Net Change $ 9.62 0.01$ $ 9.63 $ 8.14 $ 0.01 $ 8.15

Alternative Option - Total $ 10.01 0.01$ $ 10.02 $ 8.52 $ 0.01 $ 8.53

Alternative Option - Net Change $ 10.01 0.01$ $ 10.02 $ 8.52 $ 0.01 $ 8.53

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total $ 2.82 0.00$ $ 2.82 $ 2.49 $ 0.00 $ 2.49

RTCR - Net Change $ 2.82 0.00$ $ 2.82 $ 2.49 $ 0.00 $ 2.49

Alternative Option - Total $ 3.78 0.01$ $ 3.79 $ 3.57 $ 0.01 $ 3.58

Alternative Option - Net Change $ 3.78 0.01$ $ 3.79 $ 3.57 $ 0.01 $ 3.58

1989 TCR - Total $ 3.75 0.44$ $ 4.19 $ 3.60 $ 0.42 $ 4.02

RTCR - Total $ 0.26 0.06$ $ 0.32 $ 0.25 $ 0.06 $ 0.31

RTCR - Net Change $ (3.49) $ (0.38) $ (3.86) $ (3.35) $ (0.36) $ (3.71)

Alternative Option - Total $ 0.35 0.08$ $ 0.43 $ 0.35 $ 0.08 $ 0.44

Alternative Option - Net Change $ (3.40) $ (0.36) $ (3.76) $ (3.25) $ (0.34) $ (3.58)

Notes: 

2) For modeling purposes, additional routine sample counts include regular routine samples taken in the same month.

Source: Final RTCR cost model.

1) Detail may not add due to independent rounding. Because only the incremental costs of some rule components are considered as 

part of the cost analysis, references to “total” costs in this exhibit do not refer to the complete costs for regulatory implementation, 

but only to the specific costs considered to calculate net changes in costs. 

3% Discount Rate 7% Discount Rate

Rule Implementation and Annual Administration

Revising Sample Siting Plans

Routine Monitoring

Additional Routine Monitoring

Public Notification

Repeat Monitoring

Annual Site Visits

Level 1 Assessment

Level 2 Assessment

Corrective Actions based on Level 1 Assessments

Corrective Actions based on Level 2 Assessments
Economic Analysis for the Final RTCR 7-47 September 2012 

Exhibit 7.28 Total and Net Change in Annualized Costs to PWSs by PWS Size and 

Type ($Millions, 2007$) 

1989 TCR - Total RTCR - Total RTCR - Net

Alternative 

Option - Total

Alternative 

Option - Net

1989 TCR - 

Total RTCR - Total RTCR - Net

Alternative 

Option - 

Total

Alternative 

Option - Net

A B C=B-A D E=D-A F G H=G-F I J=I-F

≤100 $7.4 $7.5 $0.1 $7.6 $0.2 $7.1 $7.3 $0.2 $7.5 $0.3

101-500 $9.0 $9.4 $0.4 $9.5 $0.5 $8.6 $9.1 $0.5 $9.2 $0.6

501-1,000 $3.7 $3.8 $0.0 $3.8 $0.1 $3.6 $3.7 $0.1 $3.7 $0.1

1,001-4,100 $13.2 $13.6 $0.4 $13.6 $0.4 $12.7 $13.1 $0.4 $13.1 $0.4

4,101-33,000 $42.4 $44.8 $2.4 $44.8 $2.4 $40.7 $42.8 $2.1 $42.8 $2.1

33,001-96,000 $34.9 $36.4 $1.5 $36.4 $1.5 $33.5 $34.8 $1.3 $34.8 $1.3

96,001-500,000 $34.7 $36.2 $1.5 $36.2 $1.5 $33.4 $34.6 $1.2 $34.6 $1.2

500,001-1 Million $6.5 $6.7 $0.2 $6.7 $0.2 $6.2 $6.4 $0.1 $6.4 $0.1

> 1 Million $5.6 $5.6 ($0.0) $5.6 ($0.0) $5.3 $5.3 ($0.0) $5.3 ($0.0)

Total $157.4 $163.9 $6.5 $164.1 $6.7 $151.3 $157.2 $5.9 $157.5 $6.2

≤100 $2.6 $2.7 $0.1 $3.7 $1.1 $2.5 $2.7 $0.2 $3.8 $1.4

101-500 $1.9 $2.0 $0.1 $2.8 $0.9 $1.8 $2.0 $0.2 $2.9 $1.1

501-1,000 $0.6 $0.6 $0.1 $0.9 $0.3 $0.6 $0.6 $0.1 $0.9 $0.3

1,001-4,100 $1.2 $1.3 $0.1 $1.3 $0.1 $1.1 $1.2 $0.1 $1.2 $0.1

4,101-33,000 $0.4 $0.5 $0.1 $0.5 $0.1 $0.4 $0.5 $0.0 $0.5 $0.0

33,001-96,000 $0.1 $0.1 $0.0 $0.1 $0.0 $0.1 $0.1 $0.0 $0.1 $0.0

96,001-500,000 $0.1 $0.1 ($0.0) $0.1 ($0.0) $0.1 $0.1 ($0.0) $0.1 ($0.0)

500,001-1 Million $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0

> 1 Million $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0

Total $6.9 $7.3 $0.4 $9.3 $2.5 $6.6 $7.2 $0.6 $9.6 $3.0

≤100 $13.4 $18.7 $5.3 $28.1 $14.7 $12.8 $18.2 $5.3 $28.9 $16.1

101-500 $4.9 $6.5 $1.6 $9.5 $4.7 $4.7 $6.3 $1.6 $9.8 $5.1

501-1,000 $0.6 $0.8 $0.2 $1.2 $0.5 $0.6 $0.8 $0.2 $1.2 $0.6

1,001-4,100 $0.9 $1.0 $0.1 $1.0 $0.1 $0.9 $1.0 $0.1 $1.0 $0.1

4,101-33,000 $0.4 $0.5 $0.1 $0.5 $0.1 $0.4 $0.5 $0.0 $0.5 $0.0

33,001-96,000 $0.1 $0.1 ($0.0) $0.1 ($0.0) $0.1 $0.1 ($0.0) $0.1 ($0.0)

96,001-500,000 $0.1 $0.1 ($0.0) $0.1 ($0.0) $0.1 $0.1 ($0.0) $0.1 ($0.0)

500,001-1 Million $0.2 $0.2 ($0.0) $0.2 ($0.0) $0.2 $0.2 ($0.0) $0.2 ($0.0)

> 1 Million $0.3 $0.3 $0.0 $0.3 $0.0 $0.3 $0.3 $0.0 $0.3 $0.0

Total $20.9 $28.1 $7.3 $41.0 $20.1 $20.1 $27.3 $7.3 $42.0 $21.9

Grand Total $185.2 $199.3 $14.2 $214.4 $29.3 $177.9 $191.7 $13.8 $209.0 $31.1

Source: Final RTCR cost model.

Note: Detail may not add due to independent rounding. Because only the incremental costs of some rule components are considered as part of the cost analysis, references to “total” costs 

in this exhibit do not refer to the complete costs for regulatory implementation, but only to the specific costs considered to calculate net changes in costs. 

PWS Size

(Population

Served)

3% Discount Rate 7% Discount Rate

Community Water Systems (CWSs)

Nontransient Noncommunity Water Systems (NTNCWSs)

Transient Noncommunity Water Systems (TNCWSs)
Economic Analysis for the Final RTCR 7-48 September 2012 

Exhibit 7.29 Total and Net Change in Annualized Per PWS Costs by PWS Size and 

Type (2007$) 

1989 TCR - 

Total RTCR - Total RTCR - Net

Alternative 

Option - 

Total

Alternative 

Option - Net

1989 TCR - 

Total RTCR - Total RTCR - Net

Alternative 

Option - 

Total

Alternative 

Option - Net

A B C=B-A D E=D-A F G H=G-F I J=I-F

≤100 $564 $573 $9 $581 $17 $542 $558 $16 $569 $27

101-500 $561 $584 $23 $590 $29 $539 $568 $29 $576 $37

501-1,000 $663 $671 $8 $679 $15 $637 $654 $17 $664 $26

1,001-4,100 $1,411 $1,451 $40 $1,451 $40 $1,356 $1,401 $45 $1,401 $45

4,101-33,000 $6,707 $7,084 $377 $7,084 $377 $6,445 $6,775 $330 $6,775 $330

33,001-96,000 $33,053 $34,506 $1,453 $34,506 $1,453 $31,764 $32,971 $1,207 $32,971 $1,207

96,001-500,000 $93,620 $97,607 $3,987 $97,607 $3,987 $89,969 $93,242 $3,273 $93,242 $3,273

500,001-1 Million $185,678 $190,167 $4,490 $190,167 $4,490 $178,437 $182,027 $3,591 $182,027 $3,591

> 1 Million $277,732 $277,621 ($111) $277,621 ($111) $266,902 $266,828 ($74) $266,828 ($74)

Total $3,029 $3,153 $124 $3,158 $129 $2,911 $3,024 $113 $3,030 $119

≤100 $284 $295 $11 $406 $122 $273 $293 $20 $423 $150

101-500 $273 $291 $18 $409 $135 $263 $290 $28 $425 $163

501-1,000 $321 $349 $29 $472 $151 $308 $348 $40 $491 $183

1,001-4,100 $1,325 $1,441 $116 $1,441 $116 $1,274 $1,383 $110 $1,383 $110

4,101-33,000 $4,819 $5,382 $563 $5,382 $563 $4,631 $5,124 $493 $5,124 $493

33,001-96,000 $32,003 $33,305 $1,303 $33,305 $1,303 $30,755 $31,852 $1,096 $31,852 $1,096

96,001-500,000 $91,163 $90,898 ($265) $90,898 ($265) $87,609 $87,385 ($224) $87,385 ($224)

500,001-1 Million $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

> 1 Million $0 $0 $0 $0 $0 $0 $0 $0 $0 $0

Total $366 $390 $23 $498 $132 $352 $384 $32 $510 $158

≤100 $217 $304 $86 $457 $240 $209 $295 $87 $470 $261

101-500 $247 $327 $80 $483 $236 $237 $317 $80 $495 $257

501-1,000 $310 $408 $98 $567 $256 $298 $396 $97 $579 $281

1,001-4,100 $1,364 $1,528 $164 $1,528 $164 $1,311 $1,460 $150 $1,460 $150

4,101-33,000 $5,068 $5,679 $611 $5,679 $611 $4,871 $5,408 $537 $5,408 $537

33,001-96,000 $38,507 $38,155 ($352) $38,155 ($352) $37,008 $36,701 ($307) $36,701 ($307)

96,001-500,000 $77,791 $77,043 ($748) $77,043 ($748) $74,762 $74,090 ($672) $74,090 ($672)

500,001-1 Million $186,699 $184,841 ($1,858) $184,841 ($1,858) $179,429 $177,725 ($1,704) $177,725 ($1,704)

> 1 Million $287,010 $302,862 $15,852 $302,862 $15,852 $275,817 $291,208 $15,391 $291,208 $15,391

Total $248 $334 $86 $487 $239 $238 $325 $86 $499 $260

Grand Total $1,196 $1,287 $91 $1,385 $189 $1,149 $1,238 $42 $1,350 $154

Source: Final RTCR cost model.

Note: Detail may not add due to independent rounding. Because only the incremental costs of some rule components are considered as part of the cost analysis, 

references to “total” costs in this exhibit do not refer to the complete costs for regulatory implementation, but only to the specific costs considered to calculate net 

changes in costs. 

Transient Noncommunity Water Systems (TNCWSs)

3% Discount Rate 7% Discount Rate

Community Water Systems (CWSs)

Nontransient Noncommunity Water Systems (NTNCWSs)

PWS Size

(Population

Served)
Economic Analysis for the Final RTCR 7-49 September 2012 

Evaluation of Regulatory Options 

Exhibit 7.26 summarizes the comparison of total and annualized present value of the net 

change difference in cost from the baseline for each of the three regulatory options (1989 TCR, 

RTCR, and Alternative option). A continuation of the 1989 TCR would result in no net change in 

costs. The net change in mean annualized present value national costs of the RTCR is estimated 

to be approximately $14 million using a 3% or 7% discount rate. The net change in mean 

annualized present value national costs for the Alternative option are estimated to be 

approximately $30 million using a 3% discount rate and $32 million using a 7% discount rate. 

The total net change in national annualized present value costs for PWSs serving >4,100 

people (approximately $5.6 million at a 3% discount rate) is the same under the RTCR and 

Alternative option. This is expected because the provisions for PWSs serving >4,100 are the 

same under both the RTCR and Alternative option. Monitoring requirements for PWSs serving 

>4,100 people would remain essentially unchanged under either the RTCR or Alternative option. 

The observed overall net increase in costs for PWSs serving >4,100 people is driven primarily by 

the requirements to conduct assessments and to correct any sanitary defects that are found. 

Under the RTCR, PWSs are estimated to incur approximately 97% to 99% of the net 

annualized present value costs at 3 and 7 percent discount rates. States are expected to incur the 

remaining costs. EPA recognizes that state labor may be more expensive than PWS labor and 

that for some states, state costs may be passed onto PWSs. However, state costs are only a very 

small percentage of the total net change costs for the RTCR. 

Exhibit 7.27 presents the comparison of total and net change in annualized present value 

costs by rule component. The exhibit shows that, for the RTCR, corrective action costs are the 

most significant contributor to the net increase in costs for PWSs. For the Alternative option, 

routine monitoring costs are the most significant contributor to the net increase in costs for 

PWSs. Under the RTCR and Alternative option, state costs to review revised sample siting plans 

contribute most to the cost increase. For both PWSs and states, a net decrease in costs associated 

with PN requirements helps to offset the total net cost increase. 

The large difference in net cost increases between the RTCR and the Alternative option is 

primarily driven by the increased number of routine samples taken under the Alternative option 

in comparison to the RTCR. A larger number of samples are also estimated to result more in 

Level 1 and Level 2 triggers and to subsequently require corrective actions based on Level 1 and 

Level 2 assessments. Overall, the total net costs of the RTCR are estimated at 45% to 48% of the 

net costs of the Alternative option. This cost difference is an important consideration in the 

selection of the RTCR over the Alternative option as the preferred option. 

Exhibit 7.28 presents the total and net change in annualized costs to PWSs by size and 

type for the three regulatory options. No net change in costs would result from a continuation of 

the 1989 TCR. Among PWSs serving ≤4,100 people, the largest increase in net costs would be 

incurred by the TNCWSs serving ≤100 people under either the RTCR ($5.3 million) or 

Alternative option ($14.7 million). As shown in Exhibit 7.29, on a per system basis, this 

translates to a net annualized present value (3% discounting) increase of approximately $86 per 

system under the RTCR and $240 per system under the Alternative option for the TNCWSs 
Economic Analysis for the Final RTCR 7-50 September 2012 

serving ≤100 people. Significant impacts are also estimated for CWSs serving greater than 4,100

people, driven by the relatively high number of CWSs in this category, combined with relatively 

high unit costs for implementing corrective actions for PWSs of this size. However, PWSs of this 

size (and CWSs in general) are expected to be better able to absorb cost increases by passing 

costs through to a larger base of customers. Overall, the most important drivers of total net costs 

are the numbers of PWSs and the underlying baseline occurrence estimates in a given size 

category. Taken together, these influence the numbers of samples and ultimately the numbers of 

corrective actions taken, which drive the cost estimates. 

Exhibit 7.29 shows the costs from Exhibit 7.28 on a per-PWS basis. On this basis, the 

annual impact of the RTCR generally increases with PWS size and the magnitude of the annual 

per-PWS net costs do not appear to be prohibitive, even for the most heavily impacted PWS 

categories. However, the range of per-PWS costs is expected to be fairly wide and some 

individual PWSs may be more heavily impacted.
Economic Analysis for the Final RTCR 8-1 September 2012 

8 Economic Impact Analysis 

8.1 Introduction 

As part of the rulemaking process, the United States Environmental Protection Agency 

(EPA) is required to address the direct and indirect burdens that the Revised Total Coliform Rule 

(RTCR) may place on certain types of governments, businesses, and populations. This chapter 

presents analyses performed by the EPA in accordance with the following 14 federal mandates 

and statutory reviews: 

1. Executive Order 12866: Regulatory Planning and Review and Executive Order 

13563: Improving Regulation and Regulatory Review.

2. Paperwork Reduction Act (the Information Collection Request (ICR) document for 

the RTCR contains the complete analysis (USEPA, 2010a)). 

3. The Regulatory Flexibility Act (RFA) of 1980, as amended by the Small Business 

Regulatory Enforcement Fairness Act (SBREFA) of 1996. 

4. Unfunded Mandates Reform Act (UMRA) of 1995. 

5. Executive Order 13132: Federalism. 

6. Executive Order 13175: Consultation and Coordination with Indian Tribal 

Governments. 

7. Executive Order 13045: Protection of Children from Environmental Health Risks and 

Safety Risks. 

8. Executive Order 13211: Action Concerning Regulations That Significantly Affect 

Energy Supply, Distribution, or Use. 

9. National Technology Transfer and Advancement Act (NTTAA). 

10. Executive Order 12898: Federal Action to Address Environmental Justice in Minority 

Populations and Low-Income Populations. 

11. Consultations with the Science Advisory Board (SAB), National Drinking Water 

Advisory Council (NDWAC), and the Secretary of Health and Human Services as 

Required by Section 1412 (d) and (e) of the Safe Drinking Water Act (SDWA).

12. Impacts on Sensitive Subpopulations as Required by Section 1412(b)(3)(c)(i)(V) of 

the 1996 Amendments to the Safe Drinking Water Act. 

13. Effect of Compliance with the RTCR on the Technical, Financial, and Managerial 

Capacity of Public Water Systems as Required by Section 1420(d)(3) of SDWA. 
Economic Analysis for the Final RTCR 8-2 September 2012 

Many of the requirements and executive orders listed above call for an explanation of 

why the rule is necessary, the statutory authority for the rule, and the primary objectives that the 

rule is intended to achieve (refer to Chapter 2 for more information regarding the objectives of 

the rule). Others are designed to assess the financial and health effects of the rule on sensitive, 

low-income, and tribal populations as well as on small public water systems (PWSs). 

8.2 Executive Order 12866: Regulatory Planning and Review 

Under Executive Order 12866 (58 Federal Register (FR) 51735, October 4, 1993), the 

Agency must determine whether the regulatory action is significant and therefore subject to 

Office of Management and Budget (OMB) review and the requirements of the Executive Order. 

The Order defines “significant regulatory action” as one that is likely to result in a rule that may: 

 Have an annual effect on the economy of $100 million or more or adversely affect 

in a material way the economy, a sector of the economy, productivity, competition, 

jobs, the environment, public health or safety, or state, local, or tribal governments 

or communities; 

 Create a serious inconsistency or otherwise interfere with an action taken or 

planned by another agency; 

 Materially alter the budgetary impact of entitlement, grants, user fees, or loan 

programs or the rights and obligations of recipients thereof; or 

 Raise novel legal or policy issues arising out of legal mandates, the President’s 

priorities, or the principles set forth in the Executive Order. 

 Under Executive Order 12866, EPA has designated this action as a “significant 

regulatory action” because of the legal and policy issues raised. Accordingly, EPA submitted this 

action to the OMB for review under Executive Orders 12866 and 13563 (76 FR 3821, January 

21, 2011) and any changes made in response to OMB recommendations have been documented 

in the docket for this action. 

In addition, EPA prepared an analysis of the potential costs and benefits associated with 

this action. EPA estimates that the RTCR will have an overall annual impact on PWSs of $14 

million and that the impact on small entities (PWSs serving 10,000 people or fewer) will be 

$10.0 million–$10.3 million annualized at 3 and 7 percent discount rates, respectively. These 

impacts are described in Section 8.4 as well as sections VI and VII.C of the RTCR preamble 

(USEPA, 2010c), respectively. 

8.3 Paperwork Reduction Act 

The information collection requirements for the RTCR have been submitted for approval 

to the OMB under the Paperwork Reduction Act (PRA), 44 U.S.C. 3501 et seq. The ICR 

document prepared by EPA has been assigned EPA ICR number 1895.06. 

The PRA requires EPA to estimate the burden, as defined in 5 CFR 1320.3(b), on PWSs 

and state/primacy agencies of complying with the rule. The information collected as a result of 
Economic Analysis for the Final RTCR 8-3 September 2012 

EPA’s efforts toward proposing the RTCR should allow states/primacy agencies and EPA to 

determine appropriate requirements for specific systems and evaluate compliance with the 

RTCR. Burden is defined at 5 CFR 1320.3(b) and means the total time, effort, and financial 

resources required to generate, maintain, retain, disclose, or provide information to or for a 

federal agency. The burden includes the time needed to conduct the following state and PWS 

activities, as needed: 

State activities: 

 Read and understand the rule; 

 Mobilize (including primacy application), plan, and implement; 

 Train PWS and consultant staff; 

 Track compliance; 

 Analyze and review PWS data; 

 Review sample siting plans and recommend any revisions to PWSs; 

 Make determinations concerning PWS monitoring requirements; 

 Respond to PWSs with positive samples; 

 Recordkeeping; 

 Review completed assessment forms and consult with the PWS about the 

assessment report; 

 Review and coordinate with PWSs to determine optimal corrective actions to be 

implemented; and 

 Provide consultation, review public notification certifications, and file reports of 

violations. 

PWS activities: 

 Read and understand the rule; 

 Planning and mobilization activities; 

 Revise existing sample siting plans to identify sampling locations and collection 

schedules that are representative of water throughout the distribution system; 

 Conduct routine, additional routine, and repeat monitoring, and report the results as 

required; 
Economic Analysis for the Final RTCR 8-4 September 2012 

 Complete a Level 1 Assessment if the PWS experiences a Level 1 trigger, and 

submit a form to the state to identify sanitary defects detected, corrective actions 

completed, and a timetable for any corrective actions not already completed; 

 Complete a Level 2 Assessment if the PWS experiences a Level 2 trigger, and 

submit a form to the state to identify sanitary defects detected, corrective actions 

completed, and a timetable for any corrective actions not already completed; 

 Correct sanitary defects found through the performance of Level 1 or Level 2 

assessments and report on completion of corrective actions as required; 

 Develop and distribute Tier 1 public notices when E. coli MCL violations occur; 

 Develop and distribute Tier 2 public notices when the PWSs fail to take corrective 

action; and 

 Develop and distribute Tier 3 public notices when the PWSs fail to comply with the 

monitoring requirements or with mandatory reporting of required information 

within the specified timeframe. 

For the first three years after publication of the rule in the Federal Register, the major 

information requirements apply to 154,894 respondents. The net change in burden associated 

with moving from the information requirements of the 1989 TCR to those in the RTCR over the 

three years covered by the ICR is 2,518,577 hours, for an average of 839,526 hours per year. The 

total net change in costs (i.e., incremental costs over the 1989 TCR) over the three-year clearance 

period is $71.3 million, for an average of $23.8 million per year (simple average over three 

years). (The ICR estimate is higher than what is presented in the economic analysis (EA) for the 

RTCR because in the EA, the upfront costs that occur in the first three years, as well as future 

costs, are annualized over a 25-year time horizon.) The average burden per response (i.e., the 

amount of time needed for each activity that requires a collection of information) is 5.4 hours; 

the average cost per response is $153.4. The collection requirements are mandatory under 

SDWA (42 U.S.C. 300j-4 subsections (a)(1)(A) and (a)(1)(B)). Detail on the calculation of the 

RTCR information collection burden and costs can be found in the ICR for the RTCR and 

Chapter 7 of this EA. A summary of the burdens and costs of the collection is presented in 

Exhibit 8.1 below. 
Economic Analysis for the Final RTCR 8-5 September 2012 

Exhibit 8.1 Average Annual Net Change Burden and Costs for the RTCR 

Information Collection Request 

Annual Labor 

Cost

Annual O&M 

Cost

Annual Capital 

Cost

Total Annual 

Cost

PWSs 747,848 $ 20,171,639 $ - $ - $ 20,171,639 103,225

States and 

Territories 91,678 $ 3,595,421 $ - $ - $ 3,595,421 51,669

TOTAL 839,526 $ 23,767,060 $ - $ - $ 23,767,060 154,894

Notes: 

1) Detail may not add exactly to total due to independent rounding.

2) "Annual Burden Hours" reflects an annual average for all system sizes over the 3-year ICR period.

Respondent Type

Annual Burden 

Hours

Cost

Annual 

Responses

Source: ICR for the Final RTCR (USEPA 2010b).

An agency may not conduct or sponsor, and a person is not required to respond to, a 

collection of information unless it displays a currently valid OMB control number. The OMB 

control numbers for EPA's regulations in 40 CFR are listed in 40 CFR part 9. 

As part of the Federal Register notice on the proposed RTCR, EPA solicited comments 

on this information collection and the estimates in this ICR. EPA solicited comments on specific 

aspects of the proposed information collection, as described below: 

1. Whether the collection of information is necessary for the proper performance of the 

functions of the Agency, including whether the information will have practical utility; 

2. Whether the Agency’s burden estimate is accurate including the validity of the 

methodology and assumptions used; 

3. How to enhance the quality, utility, and clarity of the information to be collected; and 

4. How to minimize the burden on respondents, including use of appropriate automated 

electronic, mechanical, or other technological collection techniques or other forms of 

information technology. 

EPA did not receive comments that specifically referred to the ICR prepared for the 

proposed rule; however, it received several comments (such as the need to increase unit costs) on 

the associated EA, as well as the Technology and Cost Document for the Final Revised Total 

Coliform Rule (USEPA, 2010d) (which contains many of the unit costs used to estimate costs for 

the Cost Analysis and the ICR). For the RTCR, EPA revised many of the unit costs associated 

with corrective actions to incorporate those comments; these changes have been incorporated 

into this ICR. 

EPA’s responses to comments received on the proposed rule are available at 

http://www.regulations.gov, docket number EPA-HQ-OW-2008-0878. 
Economic Analysis for the Final RTCR 8-6 September 2012 

In compliance with the PRA (44 USC 3501 et seq.), EPA submitted the ICR for the 

RTCR Rule to OMB for review and approval prior to proposal. EPA did not receive any 

comments from OMB on the ICR at that time. 

8.4 The Regulatory Flexibility Act 

The RFA generally requires an agency to prepare a regulatory flexibility analysis of any 

rule subject to notice and comment rulemaking requirements under the Administrative Procedure 

Act or any other statute unless the agency certifies that the rule will not have a significant 

economic impact on a substantial number of small entities. Small entities include small 

businesses, small organizations, and small governmental jurisdictions. 

The RFA provides default definitions for each type of small entity. Small entities are 

defined as: (1) a small business as defined by the Small Business Administration’s (SBA)

regulations at 13 CFR 121.201; (2) a small governmental jurisdiction that is a government of a 

city, county, town, school district, or special district with a population of less than 50,000; and 

(3) a small organization that is any “not-for-profit enterprise which is independently owned and 

operated and is not dominant in its field.” However, the RFA also authorizes an agency to use 

alternative definitions for each category of small entity, “which are appropriate to the activities 

of the agency” after proposing the alternative definition(s) in the Federal Register and taking 

comment. 5 USC 601(3)–(5). In addition, to establish an alternative small business definition, 

agencies must consult with SBA’s Chief Counsel for Advocacy. 

For purposes of assessing the impacts of the RTCR on small entities, EPA considered 

small entities to be PWSs serving 10,000 people or fewer. This is the cutoff level specified by 

Congress in the 1996 Amendments to the SDWA for small system flexibility provisions. As 

required by the RFA, EPA proposed using this alternative definition in the Federal Register (63 

FR 7620, February 13, 1998), requested public comment, consulted with the SBA, and finalized 

the alternative definition in the Agency’s Consumer Confidence Reports Rule (USEPA, 1998b, 

63 FR 44524, August 19, 1998). As stated in that Final Rule, the alternative definition would be 

applied for all future drinking water regulations. 

After considering the economic impacts of today’s rule on small entities, EPA has 

certified that the RTCR will not have a significant economic impact on a substantial number of 

small entities. The small entities directly regulated by this rule are small PWSs serving 10,000 or 

fewer people. These include small community water systems (CWSs), non-transient 

noncommunity water systems (NTNCWSs), and transient noncommunity water systems 

(TNCWSs), entities such as municipal water systems (publicly and privately owned), and 

privately-owned PWSs and for profit businesses where provision of water may be ancillary, such 

as mobile home parks, day care centers, churches, schools and homeowner associations. In 

evaluating the impact on small PWSs, it has been determined that only 61 of 150,672 small 

systems (0.04 percent) will experience an impact of more than one percent of revenues, and that 

none of the small systems will experience an impact of three percent or greater of revenue. 

Exhibit 8.2 provides a summary of the numbers and percentages of small systems for which costs 

exceed one percent of revenues, by size category and system type using a three percent discount 

rate. Exhibit 8.3 provides a summary of the average costs and average revenues on a per system 
Economic Analysis for the Final RTCR 8-7 September 2012 

basis. See Appendix I for the detailed methodology and supporting information for the RFA 

screening analysis. 

Exhibit 8.2 RTCR - Average Annualized Revenue by System Size and Percent of 

Systems with Costs Exceeding One Percent and Three Percent of Revenue (Three 

Percent Discount Rate) 

Total

Systems

Average

Revenue/

System

1% of

Revenue

Systems

Exceeding 

1% of 

Revenue

Percent of 

Systems 

Exceeding 

1% of 

Revenue

3% of

Revenue

Systems

Exceeding 

3% of 

Revenue

Percent of 

Systems 

Exceeding 

3% of 

Revenue

A B C=B*0.01 D E=D/A F=B*0.03 G H=G/A

<500 29,150 $ 199,000 $ 2,000 60 0.21% 6,000 $ 0 0.00%

501 - 4,100 15,021 $ 1,114,000 $ 11,000 0 0.00% 33,000 $ 0 0.00%

4,101 - 10,000 3,672 $ 4,432,000 $ 44,000 1 0.03% 133,000 $ 0 0.00%

<500 15,942 $ 3,075,000 $ 31,000 0 0.00% 92,000 $ 0 0.00%

501 - 4,100 2,690 $ 11,793,000 $ 118,000 0 0.00% 354,000 $ 0 0.00%

4,101 - 10,000 80 61,663,000 $ $ 617,000 0 0.00% 1,850,000 $ 0 0.00%

<500 81,311 $ 1,811,000 $ 18,000 0 0.00% 54,000 $ 0 0.00%

501 - 4,100 2,735 $ 3,192,000 $ 32,000 0 0.00% 96,000 $ 0 0.00%

4,101 - 10,000 71 11,280,000 $ $ 113,000 0 0.00% 338,000 $ 0 0.00%

All ≤10,000 150,672 N/A N/A 61 0.04% N/A 0 0.00%

Sources: (A) SDWIS 2007 (B) Average CWS revenues from 2006 CWSS survey. Average NTNCWS and TNCWS revenues calculated 

based on representative revenues for specific business categorizations (Appendix I provides additional detail.)

(D, G) Number of systems with costs exceeding one percent and three percent of revenue calculated based on distributions of costs for 

each rule component by system size compared to the average revenues. As a function of calculations in the cost model, fractional system 

counts may be generated. Analyses in the exhibit are based only on whole system counts. (Appendix I provides additional detail.) 

Consistent with the rest of the EA, the population break is at 4,100 people rather than 3,300. This population break was based on 

TCRDSAC deliberations and consideration that concluded that breaking out the analysis at the 4,100 point would be most informative 

because of changes in the rule provisions at the 4,100 people point. (Chapter 4 provides further detail on data selection and size break 

outs.)

TNCWS

System

Type

System

Size

CWS

NTNCWS
Economic Analysis for the Final RTCR 8-8 September 2012 

Exhibit 8.3 RTCR—Average Costs per System and as Percentage of Revenue 

(2007$) 

Number

of 

Systems

Average

Annual

Net Cost/

System

Average 

Revenue/

System1

Average Annual 

Net Costs as a 

Percentage of 

Revenue

A B C D=(B/C)*100

<500 126,403 $ 60 $ 1,599,000 0.004%

501 - 4,100 20,446 $ 48 $ 2,797,000 0.002%

4,101 - 10,000 3,823 $ 276 $ 5,757,000 0.005%

All PWSs

≤10,000 150,672 $ 64 $ 1,867,000 0.003%

System

Size

1 Includes water revenues and non-water revenues (e.g., revenues related to the primary 

entities that operate a water system to support their business or municipal general revenue 

for publicly owned and operated systems). 

Although this rule will not have a significant economic impact on a substantial number of 

small entities, EPA nonetheless has tried to reduce the impact of this rule on small PWSs. 

Provisions in the RTCR that result in reduced costs for many small entities include: 

 Reduced routine monitoring for qualifying PWSs serving 1,000 or fewer people. 

 Reduced number of repeat samples required for systems serving 1,000 or fewer 

people. 

 Reduced additional routine monitoring for PWSs serving 4,100 or fewer people. 

 Reduced public notification requirements for all systems, including small systems. 

For some PWSs, cost savings may be offset in whole or in part by increased costs of 

more stringent assessment requirements, stricter rules for qualifying for reduced monitoring, or 

performing specific corrective actions. Additionally, seasonal PWSs are subject to increased 

monitoring. 

A description of activities that small systems perform under the RTCR for each rule 

component is provided in Section 7.4 of this EA along with the associated change in cost. 

Exhibit 8.4 below provides the distribution of total costs to small entities by rule component. 

Underlying these estimates are EPA’s assumptions regarding the types of corrective actions that 

will be implemented and the number of small PWSs predicted to implement each type. These 

assumptions are detailed in Appendix D of this EA. 
Economic Analysis for the Final RTCR 8-9 September 2012 

Exhibit 8.4 RTCR—Annualized Net Rule Costs Predicted for Small Entities (PWSs 

serving ≤10,000) by Rule Component Using Three Percent and Seven Percent 

Discount Rates (2007$) 

Rule Component Net Costs at 3% Net Costs at 7%

Rule Implementation $ 2,673,000 $ 3,849,000

Revising Sample Siting Plans $ 535,000 $ 755,000

Routine Monitoring $ 4,120,000 $ 3,800,000

Additional Routine Monitoring $ (2,753,000) $ (2,633,000)

Repeat Monitoring $ (178,000) $ (171,000)

Annual Site Visits $ - $ -

Level 1 Assessment $ 417,000 $ 404,000

Level 2 Assessment $ 172,000 $ 179,000

Correction Actions based on Level 1 

Assessments $ 5,159,000 $ 4,425,000

Correction Actions based on Level 2 

Assessments $ 2,642,000 $ 2,340,000

Public Notification $ (2,787,000) $ (2,674,000)

Total $ 10,000,000 $ 10,273,000

Source: Derived from cost model outputs (Appendix C).

EPA also conducted outreach to small entities and convened a Small Business Advocacy 

Review (SBAR) Panel to obtain advice and recommendations from representatives of the small 

entities that potentially would be subject to the rule's requirements. EPA consulted with small 

entity representatives before and during the review by the Panel. These small entity 

representatives included representatives from small water systems of various types and sizes, 

representatives from associations that assist and /or advocate for small systems, and federal 

agencies that operate small systems. Panel members included representatives from OMB, SBA, 

and the EPA Office of Ground Water and Drinking Water. The consultation led to the 

development of a report providing recommendations to EPA on how to revise the 1989 TCR to 

address small system concerns, which EPA considered in drafting the RTCR (SBAR Panel,

2008). EPA also made presentations to the advisory committee on the recommendations of the 

Panel so the advisory committee could consider their recommendations in developing the 

Agreement in Principle (AIP). 

Consistent with the RFA/SBREFA requirements, the SBAR Panel evaluated the 

assembled materials and small-entity comments on issues and prepared a final report to the EPA 

Administrator. A copy of the SBAR Panel report is included in the docket for this rule. The rule 

is consistent with the SBAR Panel recommendations to use total coliform (TC) as a trigger for 

investigation and/or corrective action, to balance monitoring requirements and costs with risk, to 

further differentiate requirements based on differences in water systems, to coordinate 

requirements with other related rules, and to consider reporting and recordkeeping costs in 

estimating burden.
Economic Analysis for the Final RTCR 8-10 September 2012 

EPA further reviewed the potential impacts of the RTCR on small entities in terms of the 

assumption incorporated into SDWA major rulemakings that households or residential water 

users are most vulnerable to cost increases58 (SBAR Panel, 2008). In an Assessment of the 

Vulnerability of Noncommunity Water Systems to SDWA Cost Increases (USEPA, 2008d), EPA 

considered the burden of SDWA rule costs in comparison to the average revenues of various 

categories of noncommunity water systems (NCWSs). All of the NCWS categories reviewed 

were found to be less vulnerable to SDWA-related increases than a typical household. The report 

notes that in some categories of businesses, costs are more easily passed on to the customer base 

than in others. However, in each NCWS category, expenditures on water were found to be a 

relatively small percentage of total revenues. Water expenditures (including expenditures for 

sewer service and miscellaneous other utilities) totaled less than one percent of total revenues in 

nearly all cases, and were not more than 1.3 percent of total revenues for any category. Several 

caveats were put forth in this report, including one that considered the potential for 

underestimating the impact to golf courses, which were grouped in with other recreational 

entities whose use of water was less significant to the core business than the golf courses. 

Despite the significant caveats listed, the report strongly suggests that TNCWS and NTNCWS 

should not be considered particularly vulnerable to operating cost increases resulting from 

SDWA rulemakings. 

The consistency of many of the aspects of the RTCR with the recommendations of the 

SBAR Panel further support the conclusion of the RTCR EA that the RTCR requirements are 

conducive to minimizing net impacts on small entities. Overall, the economic analysis 

summarized in Exhibit 8.2 shows that net cost increases from the RTCR over time are low 

relative to revenue. Based on this result, EPA certifies that there will not be a significant impact 

on a substantial number of small entities under the RTCR. 

8.5 Unfunded Mandates Reform Act 

The UMRA seeks to protect state, local, and tribal governments from the imposition of 

unfunded federal mandates. In addition, the Act seeks to strengthen the partnership between the 

federal government and state, local, and tribal governments and ensure that the federal 

government covers the costs incurred during compliance with federal mandates. 

Title II of the UMRA of 1995, Public Law 104-4, establishes requirements for federal 

agencies to assess the effects of their regulatory actions on state, local, and tribal governments 

and the private sector. Under section 202 of UMRA, EPA generally must prepare a written 

statement, including a cost-benefit analysis, for proposed and final rules with federal mandates 

that may result in expenditures to state, local, and tribal governments, in the aggregate, or to the 

private sector, of $100 million or more in any one year. 

Section 205 of UMRA generally requires EPA to identify and consider a reasonable 

number of regulatory options and adopt the least costly, most cost-effective or least burdensome 

option that achieves the objectives of the rule. The provisions of section 205 do not apply when 

they are inconsistent with applicable law. Moreover, section 205 allows EPA to adopt an option 

 

58 Major SDWA rulemakings generally include a section in the EA that presents an analysis of costs of the rule per 

household. 
Economic Analysis for the Final RTCR 8-11 September 2012 

other that the least costly, most cost-effective or least burdensome option if the Administrator 

publishes with the rule and explanation why that option was not adopted. 

Before EPA establishes any regulatory requirements that may significantly or uniquely 

affect small governments, including tribal governments, it must have developed under section 

203 of UMRA a small government agency plan. The plan must provide for notifying potentially 

affected small governments, enabling officials of affected small governments to have meaningful 

and timely input in the development of EPA regulatory proposals with significant federal 

intergovernmental mandates, and informing, educating, and advising small governments on 

compliance with the regulatory requirements. 

This rule does not contain a federal mandate that may result in expenditures to state, 

local, and tribal governments, in the aggregate, or to the private sector, of $100 million or more 

in any one year. Expenditures associated with compliance, defined as the net change in costs 

beyond the 1989 TCR, will not surpass $100 million in the aggregate in any year. Thus, this rule 

is not subject to the requirements of sections 202 and 205 of UMRA. 

This rule is also not subject to the requirements of section 203 of UMRA because it 

contains no regulatory requirements that might significantly or uniquely affect small 

governments. Costs to small entities are generally not significant, as described previously in 

Section 8.4 and in section VII.C of the RTCR preamble. The regulatory requirements of the 

RTCR are not unique to small governments, as they apply to all PWSs regardless of size. 

8.6 Executive Order 13132: Federalism 

Executive Order 13132, entitled “Federalism” (64 FR 43255, August 10, 1999), requires 

EPA to develop an accountable process to ensure “meaningful and timely input by state and local 

officials in the development of regulatory policies that have federalism implications.” “Policies 

that have federalism implications” is defined in the Executive Order to include regulations that 

have “substantial direct effects on the states, on the relationship between the national government 

and the states, or on the distribution of power and responsibilities among the various levels of 

government.”

This action does not have federalism implications. It will not have substantial direct 

effects on the states, on the relationship between the national government and the states, or on 

the distribution of power and responsibilities among the various levels of government as 

specified in Executive Order 13132. The net change in cost for state, local, and tribal 

governments in the aggregate is estimated to be approximately $0.2 million and $0.4 million per 

year at three percent and seven percent discount rates, respectively. Thus, Executive Order 13132 

does not apply to this rule. 

Although section 6 of Executive Order 13132 does not apply to the RTCR, EPA 

conducted a federalism consultation, consistent with Executive Order 13132, in July 2008. The 

consultation included a stakeholder meeting where EPA requested comments on the impacts of 

the potential revisions to the 1989 TCR with respect to state, county and local governments. EPA 

did not receive any comments in response to this consultation. In addition, the TCRDSAC 

included representatives of state, local and tribal governments, and through this process EPA 
Economic Analysis for the Final RTCR 8-12 September 2012

consulted with state, local, and tribal government representatives to ensure that their views were 

considered when the revisions to the 1989 TCR were developed.

In the spirit of Executive Order 13132 and consistent with EPA policy to promote 

communications between EPA and state and local governments, during proposal of the RTCR, 

EPA specifically solicited comment on this action from state and local officials. EPA conducted 

two stakeholder meetings, in April of 2009 and May of 2010, to solicit stakeholder input as it 

developed a proposed rule consistent with the recommendations of the AIP. No specific concerns 

or considerations related to Federalism were received.

8.7 Executive Order 13175: Consultation and Coordination with Indian Tribal 

Governments

Executive Order 13175, entitled “Consultation and Coordination with Indian Tribal 

Governments” (65 FR 67249, November 9, 2000), requires EPA to develop an accountable 

process to ensure “meaningful and timely input by tribal officials in the development of 

regulatory policies that have tribal implications.” The Executive Order defines “policies that 

have tribal implications: to include regulations that have “substantial direct effects on one or 

more Indian tribes, on the relationship between the federal government and the Indian tribes, or 

on the distribution of power and responsibilities between the federal government and Indian 

tribes.”

Under Executive Order 13175, EPA may not issue a regulation that has tribal 

implications, that imposes substantial direct compliance costs, and that is not required by statute, 

unless the federal government provides the funds necessary to pay the direct compliance costs 

incurred by tribal governments, or EPA consults with tribal officials early in the process of 

developing the proposed regulation and develops a tribal summary impact statement.

This action does not have tribal implications, as specified in Executive Order 13175. 

Because the requirements of the RTCR are estimated to result in low net cost increases (or in 

many cases, net cost savings) compared to the 1989 TCR requirements, the RTCR is not 

anticipated to have a negative impact on tribal PWSs.

Although Executive Order 13175 does not apply to this action, EPA consulted with tribal

officials in developing this action. EPA has consulted with tribal governments through the EPA 

American Indian Environmental Office, included a representative of the Native American Water 

Association on the advisory committee that developed recommendations regarding the proposed

rule and signed the AIP, and has addressed tribal concerns throughout the regulatory 

development process, as appropriate. The consultation included participation in three tribal

conference calls (EPA regional tribal call (February 2008), National Indian Workgroup call 

(March 2008), and National Tribal Water Conference (March 2008)). EPA requested comments 

on the 1989 TCR, requested suggestions for 1989 TCR revisions (March 2008), and presented 

possible revisions to the 1989 TCR to the National Tribal Council (April 2008). Furthermore, in 

the proposed RTCR, EPA specifically solicited additional comments on this action from tribal

officials. None of these consultations or solicitations identified issues that were particular to 

tribal entities. As a result of the tribal consultations and other tribal outreach, EPA has 
Economic Analysis for the Final RTCR 8-13 September 2012 

determined that the RTCR is not anticipated to have a negative impact on tribal systems. Thus, 

Executive Order 13175 does not apply to this action. 

8.8 Executive Order 13045: Protection of Children from Environmental Health Risks 

and Safety Risks 

Executive Order 13045 (62 FR 19885; April 23, 1997) applies to any rule initiated after 

April 21, 1998, that (1) is determined to be “economically significant” as defined under 

Executive Order 12866; and (2) concerns an environmental, health, or safety risk that EPA has 

reason to believe may have a disproportionate effect on children. If the regulatory action meets 

both criteria, EPA must evaluate the environmental, health, or safety effects of the planned rule 

on children, and explain why the planned regulation is preferable to other potentially effective 

and reasonably feasible options considered by EPA. 

The RTCR is not subject to Executive Order 13045 because it is not economically 

significant as defined in Executive Order 12866. This action’s health and risk assessments in 

relation to Executive Order 13045 are contained in section VI.K.1 of the RTCR preamble and 

Chapter 6 of the EA. This EA uses a qualitative approach in assessing the changes in risk 

anticipated for each regulatory option relative the baseline (1989 TCR). EPA expects that the 

RTCR would provide additional protection, through the additional assessments and corrective 

action required, to both children and adults who consume drinking water supplied from PWSs. 

EPA also assumes that the benefits of the rule, including reduced health risk, will 

disproportionally accrue more to children because young children are more susceptible than 

adults to some waterborne illnesses and are more likely to experience more serious effects from 

infection. For example, the risk of mortality resulting from diarrhea is often greatest in the very 

young and elderly (Rose, 1997; Gerba et al., 1996), and viral and bacterial illnesses often 

disproportionately affect children. Any overall benefits of the rule would reduce this mortality 

risk for children. 

During proposal of the RTCR, the public was invited to submit comments or identify 

peer-reviewed studies and data that assess effects of early life exposure to drinking water that 

contains fecal contaminants. No additional comments were made, nor were any additional 

studies or data identified.

8.9 Executive Order 13211: Action Concerning Regulations That Significantly Affect 

Energy Supply, Distribution, or Use 

Executive Order 13211, “Actions Concerning Regulations That Significantly Affect 

Energy Supply Distribution, or Use” (66 FR 28355, May 22, 2001), provides that agencies shall 

prepare and submit to the Administrator of the Office of Information and Regulatory Affairs, 

OMB, a Statement of Energy Effects for certain actions identified as “significant energy 

actions.” Section 4(b) of Executive Order 13211 defines “significant energy actions” as “any 

action by an agency (normally published in the Federal Register) that promulgates or is expected 

to lead to the promulgation of a final rule or regulation, including notices of inquiry, advance 

notices of proposed rulemaking, and notices of proposed rulemaking: (1)(i) that is a significant 

regulatory action under Executive Order 12866 or any successor order, and (ii) is likely to have a 

significant adverse effect on the supply, distribution, or use of energy; or (2) that is designated by 
Economic Analysis for the Final RTCR 8-14 September 2012 

the Administrator of the Office of Information and Regulatory Affairs as a significant energy 

action.”

The RTCR is not a “significant energy action” as defined in Executive Order 13211, 

because it is not likely to have a significant adverse effect on the supply, distribution, or use of 

energy. This rule is not a significant regulatory action under Executive Order 12866, and has not 

been designated by the Administrator of the Office of Information and Regulatory Affairs as a 

significant energy action, for the reasons described as follows. 

Energy Supply 

The RTCR does not regulate power generation, either directly or indirectly, and public 

and private PWSs that the RTCR applies to do not, as a general rule, generate power. Further, the 

energy cost increases borne by customers of PWSs as a result of the RTCR are a low percentage 

of the total cost of water. Therefore, power generation utilities that purchase water as part of their 

operations are unlikely to face any significant effects as a result of the RTCR. 

Energy Distribution 

The RTCR does not regulate any aspect of energy distribution and PWSs that are 

regulated by the RTCR already have electrical service. The rule is not expected to increase peak 

electricity demand at PWSs. Therefore, EPA assumes that the existing connections are adequate 

and that the RTCR has no discernible adverse effect on energy distribution. 

Energy Use 

Because the RTCR modifies existing regulations, very few PWSs are expected to make 

modifications or changes that will alter energy use patterns as a result of this rule. Therefore, 

EPA does not expect any noticeable effect on the national levels of power generation in terms of 

average and peak loads. 

8.10 National Technology Transfer and Advancement Act 

Section 12(d) of the NTTAA of 1995, Public Law No. 104-113, 12(d) (15 U.S.C. 272 

note), directs EPA to use voluntary consensus standards in its regulatory activities unless to do so 

would be inconsistent with applicable law or otherwise impractical. Voluntary consensus 

standards are technical standards (e.g., materials specifications, test methods, sampling 

procedures, and business practices) that are developed or adopted by voluntary consensus 

standards bodies. NTTAA directs EPA to provide Congress, through OMB, explanations when 

EPA decides not to use available and applicable voluntary consensus standards. 

The RTCR involves technical voluntary consensus standards. Under the RTCR, EPA will 

use several analytical methods to monitor for TC and/or E. coli as described in Standard 

Methods for the Examination of Water and Wastewater (Clesceri et al., 1998; Eaton et al., 2005). 

Methods included in Clesceri et al. (1998) and Eaton et al. (2005) are voluntary consensus 

standards. The RTCR includes 11 methods that can be used to test for TC, four of which are 

described in Clesceri et al. (1998) and Eaton et al. (2005). 
Economic Analysis for the Final RTCR 8-15 September 2012 

During proposal of the RTCR, EPA welcomed comments on this aspect of the 

rulemaking and, specifically, invited the public to identify potentially applicable voluntary 

consensus standards and to explain why such standards should be used in this regulation. 

8.11 Executive Order 12898: Federal Actions to Address Environmental Justice in 

Minority Populations and Low-Income Populations 

Executive Order 12898 (59 FR 7629, February 16, 1994) establishes federal executive 

policy on environmental justice. Its main provision directs federal agencies, to the greatest extent 

practicable and permitted by law, to make environmental justice part of their mission. Agencies 

must do this by identifying and addressing, as appropriate, any disproportionately high and 

adverse human health or environmental effects of their programs, policies, and activities on 

minority populations and low-income populations in the United States. 

EPA has determined that the RTCR will not have disproportionately high and adverse 

human health or environmental effects on minority or low-income populations because it 

increases the level of environmental protection for all affected populations without having any 

disproportionately high and adverse human health or environmental effects on any population, 

including any minority or low-income population. The RTCR applies uniformly to all PWSs. 

Consequently, the RTCR provides health protection equally to all income and minority groups 

served by PWSs. The RTCR and other drinking water regulations are expected to have a positive 

effect on human health regardless of the social or economic status of a specific population. To 

the extent that contaminants in drinking water might be disproportionately high among minority 

or low-income populations (which is unknown), the RTCR contributes toward removing those 

differences by assuring that all PWSs meet drinking water standards and take appropriate 

corrective action whenever appropriate. Thus, the RTCR meets the intent of the federal policy 

requiring incorporation of environmental justice into federal agency missions. 

8.12 Consultations with the Science Advisory Board, National Drinking Water Advisory 

Council, and the Secretary of Health and Human Services as Required by Section 

1412 (d) and (e) of the SDWA 

In accordance with section 1412(d) and (e) of the SDWA, EPA consulted with the 

Science Advisory Board (SAB), National Drinking Water Advisory Council (NDWAC), and the 

Secretary of the US Department of Health and Human Services (HHS) on the proposed RTCR. 

In addition, EPA consulted again with NDWAC and HHS before promulgation of the final 

RTCR. 

EPA met with the SAB Drinking Water Committee (DWC) and considered their 

recommendations in developing data requirements to better understand the impacts of the RTCR. 

In response to the SAB DWC recommendations, EPA also conducted sensitivity analyses, to 

explore a wider range of assumptions regarding the percentage of assessments leading to 

corrective actions and to demonstrate that using an annual average for occurrence provided 

results comparable to varying the occurrence based on the season. In addition, EPA added an 

exhibit in the EA that summarizes all significant model parameters and assumptions, their 

influence on variability and uncertainty, and their most likely effect on benefits or costs. A copy 

of the SAB report (SAB 2010) is available in the docket for the RTCR. 
Economic Analysis for the Final RTCR 8-16 September 2012 

EPA also consulted with NDWAC and requested comments in the proposed RTCR on 

areas of concern that NDWAC members raised during the consultation. EPA requested comment 

on the following: (1) whether the RTCR would be easier to implement than the 1989 TCR; and 

(2) the costs and benefits of reduced monitoring. EPA considered and addressed the comments it 

received in developing the final rule. EPA also considered NDWAC’s recommendations in 

developing the public notification requirements for the rule. 

EPA completed its consultation with HHS, as required by SDWA section 1412(d). In 

addition, EPA provided an informational briefing to the Food and Safety Group of the Food and 

Drug Administration. 

Details about EPA’s consultations (both for the proposed and Final Rule) with SAB, 

NDWAC, and HHS can be found at Section VII.K of the RTCR preamble. 

8.13 Consideration of Impacts on Sensitive Subpopulations as Required by Section 

1412(b)(3)(c)(i)(V) of the 1996 Amendments to the Safe Drinking Water Act (SDWA) 

EPA is required to seek public comment regarding the effects of contamination 

associated with the RTCR on the general population and sensitive subpopulations. Sensitive 

subpopulations include “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” (SDWA section 1412(b)(3)(C)(i)(V), 42 U.S.C 300g-1(b)(3)(C)(i)(V)). 

Pregnant and lactating women may be at an increased risk from pathogens as well as act 

as a source of infection for newborns. Infection during pregnancy may also result in the 

transmission of infection from the mother to the child in utero, during birth, or shortly thereafter. 

Since very young children do not have fully developed immune systems, they are at increased 

risk and are particularly difficult to treat. 

Infectious diseases are also a major problem for the elderly because immune function 

declines with age. As a result, outbreaks of waterborne diseases can be devastating on the elderly 

community (e.g., nursing homes) and may increase the possibility of significantly higher 

mortality rates in the elderly than in the general population. 

Immunocompromised individuals are a growing proportion of the population with the 

continued increase in HIV/AIDS, the aging population, and the escalation in organ and tissue 

transplantations. Immunocompromised individuals are more susceptible to severe and invasive 

infection. These infections are particularly difficult to treat and can result in a significantly 

higher mortality than in immunocompetent persons.

It is anticipated that the requirements of the RTCR will help reduce pathways of entry for 

fecal contamination and/or waterborne pathogens into the distribution system, thereby reducing 

exposure and risk from these contaminants in drinking water to the entire general population. 

The RTCR seeks to provide a similar level of drinking water protection to all groups including 

sensitive subpopulations, thus meeting the intent of this federal policy. See also section VI.K of 

the RTCR preamble. 
Economic Analysis for the Final RTCR 8-17 September 2012 

8.14 Effect of Compliance with the RTCR on the Technical, Financial, and Managerial 

Capacity of Public Water Systems as Required by Section 1420(d)(3) of SDWA 

Section 1420(d)(3) of the SDWA, as amended, requires that, in promulgating a National 

Primary Drinking Water Regulation, the Administrator shall include an analysis of the likely 

effect of compliance with the regulation on the technical, managerial, and financial (TMF) 

capacity of PWSs. The following analysis fulfills this statutory obligation by identifying the 

incremental impact that the RTCR will have on the TMF capacity of regulated PWSs. Analyses 

presented in this document reflect only the impact of new or revised requirements, as established 

by the RTCR; the impacts of previously established requirements on system capacity are not 

considered. 

Overall water system capacity is defined in Guidance on Implementing the Capacity 

Development Provisions of the Safe Drinking Water Act Amendments of 1996 (USEPA, 1998a) 

as the ability to plan for, achieve, and maintain compliance with applicable drinking water 

standards. Capacity encompasses three components: technical, managerial, and financial. 

Technical capacity is the operational ability of a water system to meet those SDWA 

requirements. Key issues of technical capacity include the following: 

 Source Water Adequacy—Does the system have a reliable source of water with 

adequate quantity? Is the source generally of good quality and adequately 

protected? 

 Infrastructure Adequacy—Can the system provide water that meets SDWA 

standards? What is the condition of its infrastructure, including wells or source 

water intakes, treatment facilities, storage facilities, and distribution system? What 

is the infrastructure’s life expectancy? Does the system have a capital improvement 

plan? 

 Technical Knowledge and Implementation—Are the system’s operators certified? 

Do the operators have sufficient knowledge of applicable standards? Can the 

operators effectively implement this technical knowledge? Do the operators 

understand the system’s technical and operational characteristics? Does the system 

have an effective operation and maintenance (O&M) program? 

Managerial capacity is the ability of a water system’s managers to make financial, 

operating, and staffing decisions that enable the system to achieve and maintain compliance with 

SDWA requirements. Key issues include: 

 Ownership Accountability—Are the owners clearly identified? Can they be held 

accountable for the system? 

 Staffing and Organization—Are the operators and managers clearly identified? Is 

the system properly organized and staffed? Do personnel understand the 

management aspects of regulatory requirements and system operations? Do they 

have adequate expertise to manage water system operations? Do personnel have the 

necessary licenses and certifications? 
Economic Analysis for the Final RTCR 8-18 September 2012 

 Effective External Linkages—Does the system interact well with customers, 

regulators, and other entities? Is the system aware of available external resources, 

such as technical and financial assistance? 

Financial capacity is a water system’s ability to acquire and manage sufficient financial 

resources to allow the system to achieve and maintain compliance with SDWA requirements. 

Key issues include: 

 Revenue Sufficiency—Do revenues cover costs? 

 Creditworthiness—Is the system financially healthy? Does it have access to capital 

through public or private sources? 

 Fiscal Management and Controls—Are adequate books and records maintained? 

Are appropriate budgeting, accounting, and financial planning methods used? Does 

the system manage its revenues effectively? 

8.14.1Requirements of the RTCR 

This capacity analysis is presented only for the RTCR, although EPA took similar 

considerations into account in the selection of the RTCR over the other options. This process led 

to the incorporation of less expensive rule features for systems having fewer capabilities. 

The RTCR establishes requirements that may result in the following activities that 

influence the TMF capacity of affected PWSs: 

1. Familiarization with Rule Requirements 

2. Revising Sample Siting Plans 

3. Monitoring 

4. Annual Site Visits 

5. Assessments 

6. Corrective Actions 

7. Public Notification 

8.14.2 Systems Subject to the RTCR 

The RTCR will apply to all PWSs, including 51,972 CWSs, 18,729 NTNCWSs, and 

84,136 TNCWSs—154,837 systems in all (Safe Drinking Water Information System/Federal 

Version (SDWIS/FED) 2007 4th quarter data). While most will not, some systems may require 

increased TMF capacity to comply with the new requirements, or will need to tailor their 

compliance approaches to match their capacities. Refer to section 8.14.4 for a detailed discussion 

of the changes in TMF capacity for small and large systems. 
Economic Analysis for the Final RTCR 8-19 September 2012 

8.14.3 Impact of the RTCR on System Capacity 

The estimates presented in Exhibits 8.5 and 8.6 reflect the anticipated impact of the 

RTCR on system capacity based on the expected measures that systems will be required to adopt. 

The extent of the expected impact of a particular requirement on system capacity is estimated 

using a scale of 0–5, where 0 represents a requirement that is not expected to have any impact, 1 

represents a requirement that is expected to have a minimal impact, and 5 represents a 

requirement that is expected to have a very significant impact on system capacity. Criteria used 

to develop the scores and associated impacts are discussed further in section 8.14.4. 

These impacts are assessed separately for small systems (those serving less than or equal 

to 10,000 persons, see Exhibit 8.5) and for large systems (those serving more than 10,000 

persons, see Exhibit 8.6). This distinction is necessary because most large systems will face 

fewer challenges in implementing the rule than smaller systems. For both large and small 

systems, EPA evaluated the capacity impact of each requirement on those systems affected by 

that particular requirement. Because in many cases the requirements only affect a small 

percentage of systems, the exhibits also display the number of systems and percentage of 

systems (of the subset of small or large systems) estimated to be affected by each specific 

requirement. 
Economic Analysis for the Final RTCR 8-20 September 2012 

Exhibit 8.5 Estimated Impact of the RTCR on Small Systems’ Technical, 

Managerial, and Financial Capacity 

(0 = no impact, 1 = minimal impact, and 5 = very significant impact) 

Requirement/ 

Activity 

Number 

& Percent of 

Small 

Systems 

Technical 

Capacity 

Managerial 

Capacity 

Financial 

Capacity 

Source Water AdequacyInfrastructure Adequacy Technical Knowledge and Information Ownership Accountability Staffing & Organization Effective External Linkages Revenue Sufficiency Credit Worthiness Fiscal Management & Controls 

Familiarization with 

rule requirements

150,672 (100%) 0 0 1 1 1 1 1 1 1

Revise Sample 

Siting Plans

150,672 (100%) 1 1 1 1 1 1 1 1 1

Monitoring 150,672 (100%) 0 0 2 0 2 0 2 2 2

Annual Site Visits 0 (0%) 0 0 0 0 0 0 0 0 0

Assessments* 151,456 0 0 2 0 2 0 2 2 2

Corrective Actions* 15,206 3 3 3 3 3 3 3 3 3

Public Notification* 11,701 0 0 0 0 0 0 0 0 0

Source: 

Number and percent of systems subject to each rule activity derived from Appendix A, Exhibit A.2.z. Impact on 

capacity is determined relative to previous regulations based on the cost and number of systems that require 

additional capacity to comply with each requirement, as described in section 8.14.4.

Notes: 

Small systems are those serving less than or equal to 10,000 persons. 

*For these three requirements the number of assessments, corrective actions, and public notifications over the 

25-year period of analysis (not number of systems) is shown. A corresponding percentage, therefore, is not 

meaningful for these numbers. Additional information is available in Appendix A, Exhibit A.2.z. 

1) To analyze the impact of these requirements on system capacity, the requirements believed to have the 

most and the least impact on affected systems were analyzed first. These initial analyses were then used 

as the bases against which the relative impact of the remaining requirements was assessed. The impact 

estimates developed for each requirement were also compared to those developed for the Long Term 2 

Enhanced Surface Water Treatment Rule (LT2ESWTR) and the Stage 2 Disinfectants and Disinfection 

Byproducts Rule (Stage 2 DBPR), and the Ground Water Rule (GWR) to ensure cross-rule consistency. 

2) The scores presented above represent the worst case scenario; the requirements of this rule are expected 

to have less impact on the capacity of most systems affected by each requirement.
Economic Analysis for the Final RTCR 8-21 September 2012 

Exhibit 8.6 Estimated Impact of the RTCR on Large Systems’ Technical, 

Managerial, and Financial Capacity 

(0 = no impact, 1 = minimal impact, and 5 = very significant impact) 

Requirement/

Activity 

Number 

& Percent of 

Large 

Systems 

Technical 

Capacity 

Managerial 

Capacity 

Financial 

Capacity 

Source Water AdequacyInfrastructure Adequacy Technical Knowledge and Information Ownership Accountability Staffing & Organization Effective External Linkages Revenue Sufficiency Credit Worthiness Fiscal Management & Controls 

Familiarization with 

rule requirements

4,165 (100%) 0 0 1 1 1 1 1 1 1

Revise Sample Siting 

Plans

4,165 (100%) 1 1 1 1 1 1 1 1 1

Monitoring 4,165 (100%) 0 0 1 0 1 0 1 1 1

Annual Site Visits 0 (0%) 0 0 0 0 0 0 0 0 0

Assessments* 4,617 0 0 1 0 1 0 1 1 1

Corrective Actions* 462 1 1 1 1 1 1 1 1 1

Public Notification* 334 0 0 0 0 0 0 0 0 0

Source: 

Number and percent of systems subject to each rule activity derived from Appendix A, Exhibit A.2.z. Impact on 

capacity is determined relative to previous regulations based on the cost and number of systems that require 

additional capacity to comply with each requirement, as described in section 8.14.4.

Notes: 

Large systems are those serving more than 10,000 persons. 

* For these three requirements the number of assessments, corrective actions, and public notifications over the 

25-year period of analysis (not number of systems) is shown. A corresponding percentage, therefore, is not 

meaningful for these numbers. Additional information is available in Appendix A, Exhibit A.2.z. 

1) To analyze the impact of these requirements on system capacity, the requirements believed to have the 

most and the least impact on affected systems were analyzed first. These initial analyses were then used as 

the bases against which the relative impact of the remaining requirements was assessed. The impact 

estimates developed for each requirement were also compared to those developed for the LT2ESWTR, 

Stage 2 DBPR, and GWR to ensure cross-rule consistency. 

2) The scores presented above represent the worst case scenario; the requirements of this rule are expected 

to have less impact on the capacity of most systems affected by each requirement. 

8.14.4Derivation of RTCR Scores 

EPA developed a 5-point scoring system to analyze the impact compliance with all new 

regulations will have on the TMF capacity of PWSs. For each regulation, it is necessary to 

complete the following steps: 

1. Determine the type and number of PWSs to which the regulation applies. 
Economic Analysis for the Final RTCR 8-22 September 2012 

2. List all of the requirements of the regulation. 

3. Determine the type and number of PWSs to which each requirement applies. 

4. Evaluate the impact of each requirement on the capacity of affected PWSs. 

The determination of the universe of affected systems and the evaluation of the capacity 

impact of individual requirements requires the use of the cost and technical information 

contained in the SDWIS, EAs developed for other rules, ICRs, and other supporting 

documentation for the rule. These data sources are also used to develop a qualitative description 

of the expected response of affected systems to each requirement. 

The overall evaluation of the impact of a requirement on the affected systems, presented 

in Exhibits 8.5 and 8.6, is based on the impact each requirement and activity has on nine subcategories of capacity—three sub-categories under each of the broader divisions of TMF 

capacity. Within these sub-categories, EPA evaluated the costs, number of systems affected, and 

complexity of each requirement. After estimating the technical, managerial, and financial 

impacts within each sub-category, EPA assigned the scores using best professional judgment. 

Costs were considered cumulatively for each requirement and activity for small and large 

systems. This score reflects the additional capacity that systems will need to develop to comply 

with each requirement. Due to a lack of available information on operating budgets, this analysis 

does not include a quantitative component. 

To ensure cross-rule consistency, to standardize the assignment of numerical scores, and 

to minimize the subjectivity of the scoring system, the requirements for systems under the RTCR 

are compared to the requirements of those regulations for which capacity impact analyses have 

already been conducted (e.g., Long Term 1 Enhanced Surface Water Treatment Rule 

(LT1ESWTR), LT2ESWTR, Stage 2 DBPR, GWR). Similar requirements are assigned similar 

impact scores. 

8.14.5 Small Water Systems (Those Serving 10,000 or Fewer People) 

Small systems will likely face only a small challenge to their technical and managerial 

capacity as a result of efforts to familiarize themselves with the monitoring requirements of the 

RTCR. Routine and repeat monitoring requirements under the RTCR are essentially the same as 

under the 1989 TCR, with more explicit criteria to qualify for reduced monitoring. Therefore, 

understanding the RTCR monitoring requirements is not expected to pose many new technical or 

managerial capacity issues for small systems. 

Small system technical and managerial capacity may be affected by the assessment 

requirements of the RTCR. Performing assessments may require the system to evaluate staffing 

levels and/or the need to access outside assistance to conduct the assessments in addition to 

providing training to ensure that system staff understand how those assessments are to be 

performed. Reporting, record-keeping, and data administration requirements will also affect the 

managerial capacity of small systems. 
Economic Analysis for the Final RTCR 8-23 September 2012 

Small systems that are required to take corrective action are expected to experience the 

most significant financial challenge since some corrective actions may consist of a large, onetime capital expenditure to resolve the problem. 

8.14.6Large Water Systems (Those Serving Greater Than 10,000 People) 

Large systems will likely not face any significant challenge to their technical and 

managerial capacity as a result of efforts to familiarize themselves with the RTCR. Most large 

systems are familiar with the 1989 TCR and there are no changes in the basic monitoring 

requirements for large systems under the RTCR. They are therefore assumed to already have the 

TMF capacity in place for the RTCR. 

Only large systems performing assessments and corrective actions would be expected to 

face a significant challenge meeting the TMF capacity requirements. However, this requirement 

is only necessary when monitoring reveals potential problems, and this is not expected to occur 

significantly in large systems above that experienced under the 1989 TCR. Many large systems 

already have the TMF capacity to conduct assessments and corrective actions if they are needed. 

These systems will be affected less significantly than smaller systems that have to implement 

corrective actions because it is recognized that they are typically already implementing similar 

assessments and corrective actions when a routine monitoring sample tests positive for fecal 

indicators under the 1989 TCR.
Economic Analysis for the Final RTCR 9-1 September 2012 

9 Comparison of Benefits and Costs 

9.1 National Benefits and Costs of the RTCR Considered in Comparison to the 1989 

Total Coliform Rule and Alternative Option 

The RTCR is consistent with the majority of the Total Coliform Rule/Distribution System 

Advisory Committee (TCRDSAC) Agreement in Principle (AIP). The Final Rule was developed 

in consideration of the comments received on the proposed rule and therefore is not identical to 

the AIP. Chapter 3 of this EA provides more information about the specific requirements of the 

RTCR. The primary discussion of costs and benefits in this chapter focuses on the requirements 

of the RTCR in comparison to the 1989 Total Coliform Rule (TCR) and the Alternative option 

considered. 

The primary benefit of the RTCR is to further reduce the risk of fecal contamination of 

public drinking water from the current baseline risk under the 1989 TCR. The indicator of this 

benefit that is most feasible to predict is the reduction in E. coli occurrence in public water 

systems (PWSs). As a fecal contamination indicator, E. coli can also co-occur with other 

pathogenic organisms shed in feces, such as viruses, bacteria, and pathogenic protozoa at a rate 

that is not quantified.59 EPA believes that a reduction in E. coli occurrence, together with other 

RTCR actions, will result in reduced PWS fecal contamination and will likely facilitate a 

consequent reduction in endemic and epidemic waterborne disease in the United States. 

The 1989 TCR mandates sampling for total coliforms (TC) and E. coli in PWSs in the 

U.S. However, under the 1989 TCR, PWSs that encounter samples testing positive for TC or E. 

coli have the option to implement an effective long-term corrective action, a short-term 

corrective action, or they can choose not to implement any corrective action. This wide 

variability in effectiveness of corrective actions increases the potential for exposure to fecallycontaminated drinking water when the response to E. coli occurrence is inadequate or 

ineffective. 

EPA is augmenting the 1989 TCR with, among other components, the requirement for 

systems to implement mandatory assessments and corrective actions. PWSs would be required to 

conduct either a Level 1 or Level 2 assessment, depending on the severity of a trigger (based on 

TC vs. E. coli and the number of triggers). As described in Chapter 3, the Level 1 and 2 

assessments require a PWS to more formally pursue the cause of triggers, (similar to non-acute 

or acute violations under the 1989 TCR), and to address the problem with an appropriate 

corrective action. It is the combination of these two requirements (assessments and corrective 

actions) from which most of the net benefits and costs of the RTCR would derive. Because of the 

benefits from assessment and corrective action and for the other reasons discussed in this chapter 

and in analyses and discussion presented throughout this economic analysis (EA), EPA 

concludes that the RTCR will improve public health protection compared to the 1989 TCR. 

A significant amount of the costs of the additional activities required under the RTCR 

would be offset by the reduced costs from some decreases in monitoring (additional routine and 

 

59 Chapter 2 of this economic analysis provides examples of waterborne pathogens that can occur in PWSs. Also, 

Edberg, R. (2000) discusses the use of E. coli as an indicator of drinking water quality. 
Economic Analysis for the Final RTCR 9-2 September 2012 

repeat) and decreases in public notification (PN). The decreases in monitoring may limit the 

ability of PWSs to identify E. coli positive samples at the levels found under the 1989 TCR when 

using the same monitoring techniques. However, predictive modeling results show that 

significantly more contamination events will be prevented by assessments that lead to additional 

corrective actions under the RTCR than would be missed by reduced additional routine and 

repeat monitoring for systems serving 4,100 or fewer people.60 Systems serving 4,100 people or 

more have no changes in the number of required samples under the RTCR. Some of this 

reduction in both monitoring and costs would be offset by the increase in routine monitoring 

predicted for systems serving 1,000 or fewer people because fewer systems are likely to qualify 

for reduced monitoring based on the more stringent requirements under the RTCR.61

Further cost reductions may be achieved by the revisions to the requirement for a 

mandatory sample siting plan under the RTCR, which would increase monitoring efficiency by 

having the operator revise existing sample siting plans to identifying repeat sample locations in 

addition to including regular sampling sites that are representative of the water throughout the 

distribution system. The sample siting plan may also specify repeat sample locations that may, if 

approved by the state, satisfy source water sampling requirements as well; this benefit would 

likely apply to some of the PWSs with limited or no distribution systems. 

The increases in routine monitoring for systems that no longer qualify for reduced 

monitoring, along with more efficient monitoring based on approved monitoring plans, are 

expected to increase the ability of PWSs to detect E. coli a larger percentage of the time when it 

is present. This increase in detection will be partially offset by reductions in additional routine 

and repeat monitoring. 

The Alternative option considered in this EA would provide benefits equal to or greater 

than the RTCR in terms of decreased potential health risks from PWSs delivering contaminated 

water to the public. However, monitoring costs under the Alternative option would increase 

significantly, particularly for small systems, causing a significant challenge to the effective and 

efficient implementation of the Alternative option. The remainder of this chapter provides further 

detail on the costs and benefits and how they compare under the 1989 TCR, RTCR, and 

Alternative option: 

 Section 9.1.1 discusses national benefits. 

 Section 9.1.2 discusses national costs. 

 Section 9.2 discusses uncertainty and non-quantified benefits. 

 Section 9.3 presents a comparison of regulatory options in cost/benefit terms. 

 

60 Chapter 6 of this EA explores the tradeoff in a stepwise analysis of the risk benefit resulting from implementation 

of assessments resulting in corrective actions vs. the potential increase in risk due to decreased sampling frequency. 

That analysis concludes that for each type of system and size category, the RTCR would avoid a larger number of 

acute events than it would fail to diagnose. 

61 Chapter 5 (Section 5.3) includes a description of the determination of PWS sampling frequencies that are 

applicable beginning in year 6 following RTCR promulgation. 
Economic Analysis for the Final RTCR 9-3 September 2012 

9.1.1 National Benefits of the Regulatory Options Considered 

The benefits analysis performed in this EA and summarized in this section consider the 

net changes in TC and E. coli occurrence under the RTCR as compared to the 1989 TCR.62 In 

promulgating the RTCR, EPA expects to further reduce the overall risk of contamination of 

public drinking water from the current baseline risk under the 1989 TCR. The options considered 

during development of this rule and analyzed as part of this EA are designed to achieve this 

reduction while maintaining public health protection in a cost-effective manner. 

This section examines the benefits in terms of trade-offs between compliance with the 

1989 TCR, the RTCR, and Alternative option. Based on limitations in available data (described 

further in Chapter 6, Section 6.3), EPA determined that benefits could not be calculated in terms 

of avoided cases of (or costs related to) morbidity or mortality. EPA used several methods to 

qualitatively evaluate the benefits of the RTCR. The qualitative evaluation uses both the 

judgment of EPA as informed by the TCRDSAC deliberations as well as quantitative estimates 

of changes in E. coli occurrence and counts of systems implementing corrective actions. The 

evaluation characterizes, in relative terms, the reduction in risk for each regulatory option as 

compared to baseline conditions. 

Since E. coli is an indicator of fecal contamination, EPA assumed that a decrease in E. 

coli occurrence in the distribution system would be associated with a decrease in fecal 

contamination in the distribution system. In general, this decrease in fecal contamination should 

reduce the potential risk to human health for PWS customers. Thus, any reduction in E. coli

occurrence is considered a benefit of the RTCR and Alternative option. Also, since fecal 

contamination may contain waterborne pathogens including bacteria, viruses, and parasitic 

protozoa, in general, a reduction in fecal contamination should also reduce the risk from these 

other contaminants. 

As presented in Exhibit 4.9, the percentages of samples that are positive for TC and E. 

coli are generally higher for PWSs serving 4,100 or fewer people than those serving more than 

4,100 people. PWSs with higher TC and E. coli occurrence are more likely to be triggered into 

assessments and corrective action. As discussed previously, EPA believes that the assessments 

and corrective action under the RTCR and Alternative option will lead to a decrease in TC and E. 

coli occurrence. Because the PWSs serving 4,100 people or fewer have a higher initial E. coli

occurrence and will be triggered into more assessments and corrective actions than larger PWSs, 

the increase in benefits for these small systems will be more evident as compared to the larger 

systems. In particular, model results suggest that customers of small ground water transient 

noncommunity water systems (TNCWSs) serving 100 people or fewer, which constitute 

approximately 40% of PWSs, would experience the most obvious benefit under the RTCR. That 

is, the occurrence of E. coli is predicted to decrease more for TNCWSs than for other systems 

types. 

 

62 The 1989 TCR is the baseline used in the RTCR EA, and consists of the rule components and resulting activities 

of the 1989 TCR with effects of the Ground Water Rule (GWR) implementation in 2010 incorporated. Chapter 4 of 

this EA presents information used to develop this baseline, and Chapter 5 (Section 5.3.1) describes how the 

occurrence and predictive model incorporates the GWR effects. 
Economic Analysis for the Final RTCR 9-4 September 2012 

As discussed previously, because there was insufficient data on the co-occurrence of E. 

coli and waterborne pathogens, it was not possible to quantify the health effects in the human 

population served by PWSs. Thus, EPA employed a qualitative approach as the primary method 

for analyzing the expected change in exposure to fecal contamination based on each individual 

rule component. The qualitative analysis considers the anticipated changes in sampling and 

corrective action regimens and estimates the corresponding anticipated reduction or increase in 

exposure to fecal contamination. Because the reduced exposure to fecal contamination conveys 

inadequate information about pathogen exposure, the analysis in this section is a hazard analysis 

rather than a risk analysis. Nevertheless, because the intent is to reduce risk by reducing hazard 

(potential exposure to fecal contamination and/or waterborne pathogens), risk is used as the 

discussion endpoint. Section 9.1.1.1, which follows, summarizes the results of the qualitative 

analysis, and Chapter 6 (Section 6.2) presents this information in more detail. 

Although a qualitative analysis was the primary method employed for analyzing 

potential changes in risk, quantitative measures were used to support the qualitative conclusions, 

providing additional perspective on potential changes in risk. In particular, EPA considered 

modeled predictions of the reductions in the numbers of violations/assessment triggers and of the 

number of corrective actions to be performed as they may relate to risk. Section 9.1.1.2 discusses 

the predicted changes in these outcomes. More detailed discussions of the predictive model and 

analyses results are presented in Chapters 5 and 6. 

9.1.1.1 Qualitative Comparison—Relative Risks of the RTCR and Alternative Option 

Compared to Baseline 

When revising an existing drinking water regulation, one of the main concerns is to 

ensure that backsliding on water quality and public health protection does not occur. Risk 

reduction for the RTCR is characterized by the activities performed that are presumed to reduce 

risk of exposing the public to contaminated water. These activities are considered under each 

rule component presented in Exhibit 9.1b. Under repeat and additional routine monitoring 

provisions for both the RTCR and Alternative option, there is a potential to contribute to 

increased risk for some PWS customers because TC monitoring frequency may be reduced for 

some PWSs. However, this increase in risk is expected to be more than offset by potential 

decreases in risk from increased routine monitoring and the addition of the assessments and 

corrective action provisions that will find and fix problems identified by monitoring. 

Exhibit 9.1a illustrates the predicted reduced frequency at which TC-positives occur 

subsequent to the implementation of the RTCR and Alternative option. TC occurrence is used as 

a surrogate for indicating the existence of potential pathways through which waterborne 

pathogens may enter a PWS. Exhibit 9.1a illustrates the combined effects on TC occurrence 

resulting from changes in monitoring and the effects of assessments and corrective actions for 

the different rule options illustrated. The relative trends evident in Exhibit 9.1a for TNCWSs also 

pertain to other PWS categories as illustrated in Chapter 5 and Appendix B of the RTCR EA. 

EPA chose to include the characterization for TNCWSs because they represent the system 

category of largest influence on the national impacts. 
Economic Analysis for the Final RTCR 9-5 September 2012 

Exhibit 9.1a Ground Water (GW) Transient Noncommunity Water Systems 

(Serving ≤ 4,100) TC Occurrence 

Notes: 

1) Six Year 2005 TC-positive occurrence is representative of all GW TNCWS. The rate presented may 

underestimate the occurrence for systems serving 25-4,100 individuals. 

2) Graph shows the 30-year modeled period discussed in Ch. 5. Model years 3–27 represent the 25-year 

period of analysis for this EA. Model year 11 begins the steady state, during which systems that 

qualified for reduced monitoring are now sampling on their reduced schedules. The criteria and timing 

of this monitoring adjustment is discussed in Section 5.3.2.2 of this EA. 

3) The results represented by the curves for 1989 TCR, RTCR, and Alternative option all incorporate the 

effects of the GWR. 

The effect that the changes to PN requirements for monthly/non-acute MCL violations 

have on risk is difficult to predict. Some factors, such as reduction in available public 

information and possible PWS complacency, lead to a potential increase in risk, whereas other 

factors, such as less confusion (PN more in line with potential health risks) and PWSs resources 

used more efficiently, lead to a potential decrease, as discussed in Exhibit 9.1b. This change to 

PN addresses a key concern expressed by various stakeholders in the advisory committee and 

during the Six-Year Review 1 comment solicitation process. By revising the PN requirements 

and adding assessment and corrective action requirements, the Agency expects less public 

confusion, more effective use of resources, and increased transparency. Other rule components 

are expected to have a negligible effect on risk. However, the overall effect of the RTCR is 

expected to be a further reduction in risk from the current baseline risk under the 1989 TCR. 
Economic Analysis for the Final RTCR 9-6 September 2012 

Chapter 6 presents a detailed discussion of the potential influence on health risk for each rule 

component. 
Economic Analysis for the Final RTCR 9-7 September 2012 

Exhibit 9.1b Potential Changes in Risk under the RTCR and Alternative Option Relative to the 1989 TCR 

Rule Component

Factors Leading to a Potential 

Increase in Risk

Factors Leading to a Potential Decrease in 

Risk

Overall Predicted Change in 

Risk

RTCR Alternative 

option RTCR Alternativeoption RTCR Alternative option

Implementation 

Activities

None None None None No change No change

Routine 

Monitoring 

(Including 

Reduced 

Monitoring)

None None Increased stringency 

in requirements to 

qualify for reduced 

monitoring along with 

requirement to return 

to baseline monitoring 

upon loss of these 

criteria is expected to 

result in decreased 

risk (i.e., PWSs that 

qualify for reduced 

monitoring will be 

better operated, PWSs 

that no longer qualify 

will monitor more 

frequently).

PWSs all monitor monthly 

in the first few years of 

implementation of the 

RTCR, which is an 

increase in sampling 

frequency for systems 

that monitor quarterly or 

annually under the 1989

TCR. After the first few 

years, systems may 

reduce to quarterly, but 

none may reduce to 

annual monitoring, 

creating a decrease in risk 

for systems on annual 

monitoring under the 1989

TCR.

Decrease Decrease

Repeat 

Monitoring

Required repeat 

samples reduced 

from 4 to 3 for 

systems serving 

≤1,000 people

Required repeat 

samples reduced 

from 4 to 3 for 

systems serving 

≤1,000 people

None None Increase Increase
Economic Analysis for the Final RTCR 9-8 September 2012 

Rule Component Factors Leading to a Potential 

Increase in Risk

Factors Leading to a Potential Decrease in 

Risk

Overall Predicted Change in 

Risk

Additional 

Routine 

Monitoring

Additional routine 

samples are no 

longer required for 

PWSs monitoring 

monthly.

Ground water 

PWSs serving 

≤1,000 people 

would reduce 

additional routine 

samples from 5 to 

3.

Additional routine 

samples are no 

longer required 

for PWSs 

monitoring 

monthly.

Ground water 

PWSs serving 

≤1,000 people 

would reduce 

additional routine 

samples from 5 to 

3.

None None Increase Increase

Annual Site Visits None (only states

currently 

performing annual 

site visits are 

expected to 

continue)

Annual 

monitoring is not 

permitted so 

annual site visits 

will no longer be 

conducted.

None (only states 

currently performing 

annual site visits are 

expected to continue)

None No change Increase

Assessments None None Mandatory 

assessments are a 

new requirement.

Mandatory assessments 

are a new requirement.

Decrease Decrease

Corrective 

Actions

None None Mandatory corrective 

actions are a new 

requirement. 

Mandatory corrective 

actions are a new 

requirement. 

Decrease Decrease

PN —

Monthly/NonAcute MCL 

Violations

Reduction in 

available public 

information

Possible PWS

complacency

Reduction in 

available public 

information

Possible PWS 

complacency

Less confusion (PN 

more in line with 

potential health risks)

PWS resources used 

more efficiently

Less confusion (PN more 

in line with potential 

health risks)

PWS resources used 

more efficiently

Unknown Unknown
Economic Analysis for the Final RTCR 9-9 September 2012

Rule Component Factors Leading to a Potential 

Increase in Risk

Factors Leading to a Potential Decrease in 

Risk

Overall Predicted Change in 

Risk

PN—Monitoring 

and Reporting 

Violations

None None Improved focus of 

required PN for rule 

aspects with potential 

adverse health 

consequences, 

notably E. coli MCL 

violations and failure 

to conduct 

assessments and 

corrective actions, will 

motivate PWSs to 

conduct sampling and 

other treatment 

technique 

requirements.

Improved focus of 

required PN for rule 

aspects with potential 

adverse health 

consequences, notably E. 

coli MCL violations and 

failure to conduct 

assessments and 

corrective actions, will 

motivate PWSs to 

conduct sampling and 

other treatment technique 

requirements.

Decrease Decrease

Overall Empty cell Empty cell Empty cell Empty cell Decrease Decrease

Note:

1) Detailed discussion of the rationale for determinations of potential risk for each rule component is presented in Ch. 6 (Section 6.2) of this EA. Implementation 

activities consist of administrative activities by PWSs and states to implement the rule.

2) Assessment of potential changes in risk for monitoring components is an overall assessment. Potential changes (or static state) of risk for particular system 

sizes and types differ according to individual regulatory requirements and are discussed in Section 6.2. Chapter 3 provides a detailed description of the 

regulatory components for all three regulatory options, and the preamble to the RTCR provides additional discussion of the TCRDSAC process and the 

rationale underlying the structure of the regulatory options considered.
Economic Analysis for the Final RTCR 9-10 September 2012 

9.1.1.2 Comparison of Quantified Benefits between 1989 TCR and RTCR and 

Alternative Option 

The quantified portion of the benefits analysis focuses on several measures that 

contribute to the changes in risk expected under the RTCR. Specifically, EPA modeled the 

predicted outcomes based on each regulatory option considered—baseline (1989 TCR), the 

RTCR, and the Alternative option—in the form of estimates of non-acute violations for the 1989 

TCR and assessment triggers for the RTCR and Alternative option; E. coli violations; and the 

number of corrective actions implemented under each option. 

This section presents a summary of the estimated impacts of the RTCR and Alternative 

option in comparison to the 1989 TCR. Evaluation of each of these endpoints informed EPA’s 

understanding of potential changes to the underlying quality of drinking water. In particular, the 

number of corrective actions performed has a strong relationship to potential improvements in 

water quality and public health. For a given level of TC and E. coli occurrence, an increase in the 

number of corrective actions implemented would lead to improved water quality. However, a 

reduction in sampling leads to a reduction in TC and E. coli positives being found, which in turn 

leads to a reduction in assessments and corrective actions being implemented. The number of TC

and E. coli positives that are prevented, missed, or found under each regulatory option is 

considered in comparison to those predicted under the 1989 TCR results in estimates of annual 

non-acute and acute violations (1989 TCR) and assessment triggers (RTCR and Alternative 

option). Section 6.4 of this EA presents a step-wise uncertainty analysis of the competing effects 

of additional protective activity (assessments and corrective actions) and decreased additional 

routine and repeat sampling of the regulatory options compared to the 1989 TCR. The results of 

this uncertainty analysis showed that for all categories of systems, more TC and E. coli positives 

would be prevented than missed. 

For each of the graphs presented in Exhibit 9.2 through Exhibit 9.7 there are two main 

model drivers that impact the endpoints depicted: the total number of samples taken over time 

(including routine, additional routine, and repeat) and corrective actions taken. When looking at 

the comparisons between the 1989 TCR with the RTCR across all PWSs, the overall impact of 

the total numbers of samples taken is negligible because the total number of samples predicted to 

be taken throughout the period of analysis is almost the same (approximately 82 million samples 

under either the 1989 TCR or the RTCR) as shown in Exhibits 6.2–6.4 of this EA. For the 

Alternative option, the analysis predicts that approximately 88 million total samples will be taken 

over the period of analysis. Based on the relationships of total samples taken between the 1989 

TCR, RTCR, and Alternative option, the best way to interpret the graphs presented in this section 

is in a step-wise manner. 

The first comparison is between the 1989 TCR and the RTCR. Because a similar total 

number of samples is taken under the 1989 TCR and RTCR, the major effect seen in the graphs 

can be isolated to the effects that implementation of corrective actions will have on underlying 

occurrence and how that occurrence influences the endpoint in question. In each graph, this is 

depicted by a marked reduction in the endpoint under the RTCR compared to the TCR and is a 

reflection of overall better water quality. The second comparison can then be made of the 

Alternative option against the RTCR. In each graph, the endpoints for the Alternative option are 

above those for the RTCR and represent an additional benefit over the RTCR. This additional 
Economic Analysis for the Final RTCR 9-11 September 2012 

benefit is primarily a function of the additional diagnostic abilities gained through increased 

monitoring under the Alternative option, and is especially prominent in the early years of the 

analysis when all systems are required to monitor at least monthly. 

More detailed descriptions of each endpoint considered in terms of the evaluation process 

described previously are provided in this section as they apply to the individual graphs in 

Exhibits 9.2 through 9.7. The graphs shown in this section are presented first in nondiscounted 

terms and then based on a discount rate of 3% to reflect the reduced valuation of potential 

benefits over time, consistent with the presentation of costs in the section that follows. Graphs of 

benefits discounted using 7% discount rates are presented in Appendix B to this EA. 

Exhibit 9.2 shows the effect (on average across all PWSs) of the RTCR and the 

Alternative option on the annual number of non-acute violations (Level 1 assessment triggers 

under the RTCR and Alternative option) over time. The estimated reduction of approximately 

1,100 trigger events in moving from the 1989 TCR to the RTCR is a net result from the 

following effects described previously in this section: improved water quality (events prevented); 

retained diagnostic power (events found), which in turn leads to prevention of some future 

events; and reduced diagnostic power (missed events). The amount of this reduction would be 

some amount lower if the analysis could account for events where contamination was present but 

not diagnosed (missed events). This is why a similar, but smaller, reduction from the 1989 TCR 

is seen under the Alternative option. During the first 9 years of sampling under the RTCR and 

Alternative option sampling regimens, diagnostic power under the Alternative option is at a 

maximum based on the all-monthly sampling requirement. In year 9, following a 5-year period 

of assessment,63 all systems that qualified for reduced monitoring begin sampling according to 

their new regimens. This is the start of the relatively steady state of the period of analysis, driven 

by the static nature of the percentages of systems following monthly, quarterly, or annual 

sampling regimens throughout the remainder of the analysis (years 9 through 25). Trigger events 

under the Alternative option remain at a higher steady state than under the RTCR based on the 

increased diagnostic ability provided by more frequent sampling under the Alternative option. 

The additional number of triggers identified by increased sampling under the Alternative option 

translates into greater potential benefits than those under the RTCR. 

Exhibit 9.3 shows the effect (on average across all PWSs) of the RTCR and the 

Alternative option with respect to acute (E. coli) violations found over the 25-year period of 

analysis in comparison to the 1989 TCR. The overall reduction in annual acute violations under 

the RTCR of approximately 170 events is a measure that should correlate more closely with 

expected benefits (i.e., reductions in adverse health outcomes) than non-acute violations because 

acute violations are a direct result of measurement of E. coli in water. Again a similar, but 

smaller, reduction is seen under the Alternative option after steady state is achieved. This is the 

result of two off-setting effects. The true number of steady state violations under the Alternative 

option is lower, because there is a greater likelihood that violations will be found and fixed. 

However, the additional monitoring leads to a higher percentage of violations being detected. 

This second effect outweighs the first, so that the total number of detected violations in the 

steady state is higher than for the RTCR, even though the underlying true number of violations is 

 

63 The assessment period is 3 years for CWSs, and CWSs begin sampling on their reduced regimens in year 7 after 

promulgation. 
Economic Analysis for the Final RTCR 9-12 September 2012 

lower. This lower number of true violations means that the Alternative option is more protective 

of public health, even though more violations are detected. 

Exhibit 9.4 presents estimates over the 25-year period of analysis of the increase in 

corrective actions (on average across all PWSs) attributable to the regulatory options considered. 

The performance of these additional corrective actions is expected to result in the most direct 

benefits under the RTCR. Because only the numbers of net corrective actions estimated under 

the RTCR and Alternative option (i.e., corrective actions in addition to those estimated under the 

1989 TCR) were modeled, the reference point for comparison to the 1989 TCR is the base (zero) 

line in the graph. The RTCR EA assumes that corrective actions are being performed under the 

1989 TCR. These are taken into account by assuming only a modest net increase in effective 

corrective actions implemented, calculated as 10% of assessments performed under each 

regulatory option that are net of those performed under the 1989 TCR. 

Exhibit 9.4 indicates that more corrective actions would be implemented under the 

Alternative option than under the RTCR. This is driven, again, by the increased diagnostic power 

of more sampling and reflects additional potential benefits beyond those gained under the RTCR. 

However, not quantified are the numbers of corrective actions that would be identified by the 

annual inspections required to qualify for annual monitoring under the RTCR but not under the 

Alternative option. Inclusion of the additional corrective actions taken under the RTCR due to 

the annual inspection requirement could narrow the difference between the potential benefits of 

the Alternative option and the RTCR. 

Taken together, Exhibits 9.2–9.4 indicate that the modeled endpoints for the RTCR and 

Alternative option predict positive benefits in comparison to the 1989 TCR; in particular, the 

Alternative option would capture more benefits than the RTCR. These outcomes are consistent 

with the qualitative assessment of the benefits summarized in Section 9.1.1.1. 

The assessment based on Exhibits 9.5–9.7 is also consistent with the qualitative analysis 

in Section 9.1.1.1. For each of the discounted endpoints presented over time in Exhibits 9.5–9.7, 

the graphs show that (on average across all PWSs) the Alternative option would provide more 

benefits than the RTCR, and both provide more benefits than the 1989 TCR. The major 

difference between the RTCR and Alternative option is the increased monitoring that would be 

required under the Alternative option. The increased diagnostic ability of the extra samples taken 

under the Alternative option is seen in the large difference in the endpoint counts through the 

first several years in the following graphs. Absent this effect, the Alternative option would mirror 

the RTCR in the graphs. Thus, even though the predicted endpoints are greater than the 1989 

TCR at first, it is due to initially finding more problems through monitoring. This would reflect a 

frontloading of benefits under the Alternative option at the beginning of the implementation 

period. The benefits, however, would tend to even out over time between the RTCR and 

Alternative option as eligible systems qualify for less frequent (quarterly) monitoring under the 

Alternative option. 
Economic Analysis for the Final RTCR 9-13 September 2012 

Exhibit 9.2 Estimates of Non-Acute Violations (TCR) and Level 1 Assessment 

Triggers (RTCR and Alternative Option) 

Source: RTCR occurrence model output. 

Notes: 

1) The X-axis begins at Year 4 after rule promulgation, which is the first year under full implementation of the 

RTCR or Alternative option. 

2) The annual rates of non-acute violations (TCR) and Level 1 assessment triggers (RTCR and Alternative 

option) as predicted by the model reach a steady state beginning in approximately Year 9, by which time 

PWSs that would be expected to meet the criteria for reduced monitoring would have begun it. 

3) Non-acute violations/Level 1 assessment triggers are predicted to be lower under the RTCR because, 

although both options are preventing contamination events as discussed in Section 6.3 of this EA, the 

Alternative option is finding more because of its increased sampling and correspondingly higher diagnostic 

power. 
Economic Analysis for the Final RTCR 9-14 September 2012 

Exhibit 9.3 Estimates of Acute Violations (TCR) and E. coli MCL Violations (RTCR 

and Alternative Option) 

Source: RTCR occurrence model output. 

Notes: 

1) X-axis begins at Year 4 after rule promulgation, which is the first year under full implementation of the RTCR or 

Alternative option. 

2) The annual rates of acute violations (TCR) and E. coli violations (RTCR and Alternative option) as predicted by 

the model reach steady state in approximately Year 9, by which time PWSs that would be expected to meet the 

criteria for a reduced monitoring schedule would have begun it. Estimates represent the annual number of acute 

violations found by each option and the TCR. 

3) Acute violations are predicted to be lower under the RTCR because, although both options are preventing 

contamination events as discussed in Section 6.3 of this EA, the Alternative option is finding more because of 

its increased sampling and correspondingly higher diagnostic power. 
Economic Analysis for the Final RTCR 9-15 September 2012 

Exhibit 9.4 Estimates of Corrective Actions 

Source: RTCR occurrence model output. 

Notes: 

1) X-axis begins at Year 4 after rule promulgation, which is the first year under full implementation of the RTCR or 

Alternative option. The annual rates of corrective actions as predicted by the model reach a steady state 

beginning approximately in Year 9, by which time PWSs that would be expected to meet the criteria for reduced 

monitoring would have begun it. 

2) Includes L1 and L2 corrective actions. All corrective actions performed are in addition to activity under the 1989 

TCR, which does not require corrective actions. Therefore the 1989 TCR is not included in this graph. 

3) Corrective actions are predicted to be higher under the Alternative option because, although both options are 

preventing contamination events as discussed in Section 6.3 of this EA, the Alternative option is finding more 

because of its increased sampling and correspondingly higher diagnostic power. 
Economic Analysis for the Final RTCR 9-16 September 2012 

Exhibit 9.5 Discounted Estimates of Non-Acute Violations (TCR) and Level 1 

Assessment Triggers (RTCR and Alternative Option) (3% Discount Rate) 

Source: RTCR occurrence model output. 

Notes: 

1) X-axis begins at Year 4 after rule promulgation, which is the first year under full implementation of the RTCR or 

Alternative option. 

2) The annual rates of non-acute violations (TCR) and Level 1 assessment triggers (RTCR and Alternative 

option) as predicted by the model reach a steady state beginning in approximately Year 9, by which time 

PWSs that would be expected to meet the criteria for reduced monitoring would have begun it. 

3) Non-acute violations/Level 1 assessment triggers are predicted to be lower under the RTCR because, 

although both options are preventing contamination events as discussed in Section 6.3 of this EA, the 

Alternative option is finding more because of its increased sampling and correspondingly higher diagnostic 

power. 
Economic Analysis for the Final RTCR 9-17 September 2012 

Exhibit 9.6 Discounted Estimates of Acute Violations (TCR) and E. coli MCL 

Violations (RTCR and Alternative Option) (3% Discount Rate) 

Source: RTCR occurrence model output. 

Notes: 

1) X-axis begins at Year 4 after rule promulgation, which is the first year under full implementation of the RTCR or 

Alternative option. 

2) The annual rates of acute violations (TCR) and E. coli violations (RTCR and Alternative option) as predicted by 

the model reach steady state in approximately Year 9, by which time PWSs that would be expected to meet the 

criteria for reduced monitoring would have begun it. 

3) Acute violations are predicted to be lower under the RTCR because, although both options are preventing 

contamination events as discussed in Section 6.3 of this EA, the Alternative option is finding more because of 

its increased sampling and correspondingly higher diagnostic power. 
Economic Analysis for the Final RTCR 9-18 September 2012 

Exhibit 9.7 Discounted Estimates of Corrective Actions 

(3% Discount Rate) 

Source: RTCR occurrence model output. 

Notes: 

1) X-axis begins at Year 4, which is the first year under full implementation of the RTCR or Alternative option. 

2) Includes L1 and L2 corrective actions. The annual rates of corrective actions as predicted by the model reach 

a steady state beginning in approximately Year 9, by which time PWSs that would be expected to meet the 

criteria for reduced monitoring would have begun it. All corrective actions performed are in addition to activity 

under the 1989 TCR, which does not require corrective actions. Therefore the 1989 TCR is not included in this 

graph. 

3) Corrective actions are predicted to be higher under the Alternative option because, although both options are 

preventing contamination events as discussed in Section 6.3 of this EA, the Alternative option is finding more 

because of its increased sampling and correspondingly higher diagnostic power. 

9.1.2 National Cost Summary 

To understand the net impacts of the RTCR on PWSs and states, EPA first used available 

data, information, and best professional judgment to characterize how PWSs and states are 

currently implementing the 1989 TCR. Then, EPA considered the net change in costs (i.e., 

incremental costs over the 1989 TCR) that would result from implementing the RTCR or 
Economic Analysis for the Final RTCR 9-19 September 2012 

Alternative option as compared to the costs of continuing with the 1989 TCR. The objective was 

to provide the net change in costs resulting from revisions to the 1989 TCR rather than absolute 

total costs of implementing the TCR as revised by the RTCR. The exhibits in this section present 

this net change in costs several different ways to help analyze the impacts of the RTCR. 

Costs are estimated for different PWS types and size categories (nine size categories are 

used based on population served) using unit costs obtained from the advisory committee 

technical work group and vendors and presented in the Technology and Cost Document for the 

Final Revised Total Coliform Rule (USEPA, 2010d). Cost analyses for PWSs include estimates 

to implement the rule; to revise sample siting plans; to conduct routine monitoring, additional 

routine monitoring, and repeat monitoring; to perform Level 1 and Level 2 assessments and 

implement corrective actions; and to provide PN in the case of violations. State cost analyses 

include estimates of the labor burdens that states would incur, including staff training on RTCR 

requirements and conducting annual administration, reviewing monitoring reports, reviewing and 

approving corrective action plans, and for recordkeeping. Chapter 7 of this EA provides detailed 

discussion on the underlying cost-buildup for each rule component analyzed within the cost 

model. 

Considering costs over time, Exhibits 9.8 through 9.10 show that most of the cost 

difference between the RTCR and Alternative option will be experienced in the first 8 years after 

promulgation. Nevertheless, the costs of the RTCR remain lower than those of the Alternative 

option throughout the period of analysis. The lower costs of the RTCR are driven by the 

monitoring requirements of the respective options (e.g., RTCR allows annual monitoring for 

qualifying PWSs while the Alternative option requires at least quarterly monitoring for all 

PWSs). 

Exhibit 9.11 presents the total and net change in costs for PWSs and states for the 1989 

TCR, the RTCR, and the Alternative option. The estimated net change in costs is relatively small 

for PWSs and states on a national level; for the RTCR, total costs would increase from the 1989 

TCR by approximately 8%, or $14 million (using a 3 percent discount rate). The Alternative 

option, based on the increased sampling regimen, increases total costs from baseline by 

approximately 16%, or about $30 million (using a 3 percent discount rate). Given these relatively 

low net costs, both the RTCR and Alternative option are below the threshold of a “significant 

regulatory action” under Executive Order 12866. The approximate $16 million difference 

between the RTCR and the Alternative, and the net cost of each option over the 1989 TCR, are 

not particularly large in absolute terms compared to a threshold for economic significance of 

$100 million annually. 

As shown in Exhibit 9.11, the largest portion of the net cost increase is borne by PWSs, 

which incur approximately 99% of the RTCR’s net annualized present value costs (using a 3 

percent discount rate). States are expected to incur the remaining costs. PWS costs represent only 

an 8% and 16% increase, respectively, for the RTCR and Alternative option, in costs over those 

estimated for the 1989 TCR. By comparison, state costs are expected to increase by 16% and 

34% under the RTCR and Alternative option, respectively; however, state costs remain relatively 

low in absolute terms. The higher net change in PWS costs reflects the potential impact on the 

subsets of PWSs (primarily small TNCWSs) that would be most affected by either the RTCR or 

the Alternative option. Exhibit 9.13 shows that the greatest cost impact is on the smallest subset 
Economic Analysis for the Final RTCR 9-20 September 2012 

of TNCWSs, for which the net change is more than double under the Alternative option as 

compared to the RTCR. The frontloading of costs (shown in Exhibits 9.8 through 9.10) would 

further amplify the impacts on small TNCWSs during the first few years of rule implementation. 

Comparison of Costs of the Regulatory Options Considered 

EPA estimated the net change in costs of the RTCR and Alternative option as compared 

to the baseline (1989 TCR). 

Exhibit 9.12 presents the total and net change in costs to PWSs and states by rule 

component for each of the regulatory options considered. For PWSs, the main driver of 

additional costs under the RTCR and Alternative option would be additional corrective actions 

and increases in routine monitoring. Offsetting the cost increase are reductions in costs for 

additional routine monitoring and PN. 

Under the RTCR and Alternative option, the main drivers of net cost increases for states 

are reviews of revised sample siting plans. States are expected to see a reduction in costs for PN, 

and additionally for assessment activities under the RTCR. States would, however, experience an 

overall estimated increase in net costs of $0.2 million and $0.3 million for the RTCR and 

Alternative option, respectively. The additional costs associated with the Alternative option 

would result from the increased sampling (and reporting) frequency, and the resulting increase in 

assessments and corrective actions. 

Exhibit 9.13 presents the total and net change in costs to PWSs by system size and type. 

For PWSs, the most significant total net cost impact is for the smallest category of TNCWSs 

(serving ≤100 people). Approximately 38% of the net cost increase under the RTCR is estimated 

to fall on these systems. This is an important factor in the evaluation of potential impacts when 

comparing regulatory options. 
Economic Analysis for the Final RTCR 9-21 September 2012 

Exhibit 9.8 Net Costs to PWSs (2007$) 

Source: RTCR occurrence model output. 

Note: X-axis begins at Year 4, which is the first year of implementation of the RTCR or Alternative option. Steady 

state begins in approximately Year 9, by which time PWSs that would be expected to meet the criteria would 

have qualified for and would begin reduced monitoring. 
Exhibit 9.9 Discounted Net Costs to PWSs Over Time (3% Discount Rate) (2007$)

Economic Analysis for the Final RTCR 9-22 September 2012 

Source: RTCR cost model. 

Note: X-axis begins at Year 4, which is the first year of implementation of the RTCR or Alternative option. Steady 

state begins in approximately Year 9, by which time PWSs that would be expected to meet the criteria would have 

qualified for and would begin reduced monitoring. 
Exhibit 9.10 Discounted Net Costs to PWSs (7% Discount Rate) (2007$) 

Economic Analysis for the Final RTCR 9-23 September 2012 

Source: RTCR cost model. 

Note: X-axis begins at Year 4, which is the first year of implementation of the RTCR or Alternative option. Steady 

state begins in approximately Year 9, by which time PWSs that would be expected to meet the criteria would have 

qualified for and would begin reduced monitoring. 
Economic Analysis for the Final RTCR 9-24 September 2012 

Exhibit 9.11 Comparison of Total and Net Change in Annualized Present Value 

Costs ($Millions, 2007$) 

PWSs State Total PWSs State Total

1989 TCR - Total $ 185 0.9$ $ 186 $ 178 $ 0.9 $ 179

RTCR - Total $ 199 1.1$ $ 200 $ 192 $ 1.3 $ 193

RTCR - Net Change $ 1 4 0.1$ $ 1 4 $ 1 4 $ 0.4 $ 1 4

RTCR - Percent Change 8% 16% 8% 8% 48% 8%

Alternative Option - Total $ 214 1.2$ $ 216 $ 209 $ 1.5 $ 210

Alternative Option - Net Change $ 2 9 0.3$ $ 3 0 $ 3 1 $ 0.6 $ 3 2

Alternative Option - Percent Change 16% 34% 16% 17% 69% 18%

Source: Final RTCR cost model.

Note: Detail may not add due to independent rounding. Because only the net change in costs of some rule components are considered as 

part of the cost analysis, references to “total” costs in this exhibit do not refer to the complete costs for regulatory implementation, but 

only to the specific costs considered to calculate net changes in costs. 

3% Discount Rate 7% Discount Rate
Economic Analysis for the Final RTCR 9-25 September 2012 

Exhibit 9.12 Comparison of Total and Net Change in Annualized Present Value 

Costs by Rule Component ($Millions, 2007$) 

PWSs State Total PWSs State Total

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total $ 2.77 0.18$ $ 2.95 $ 4.00 $ 0.26 $ 4.26

RTCR - Net Change $ 2.77 0.18$ $ 2.95 $ 4.00 $ 0.26 $ 4.26

Alternative Option - Total $ 2.77 0.18$ $ 2.95 $ 4.00 $ 0.26 $ 4.26

Alternative Option - Net Change $ 2.77 0.18$ $ 2.95 $ 4.00 $ 0.26 $ 4.26

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total $ 0.59 0.42$ $ 1.01 $ 0.84 $ 0.59 $ 1.42

RTCR - Net Change $ 0.59 0.42$ $ 1.01 $ 0.84 $ 0.59 $ 1.42

Alternative Option - Total $ 0.59 0.42$ $ 1.01 $ 0.84 $ 0.59 $ 1.42

Alternative Option - Net Change $ 0.59 0.42$ $ 1.01 $ 0.84 $ 0.59 $ 1.42

1989 TCR - Total $ 170.59 -$ 170.59 $ $ 163.94 -$ 163.94 $ 

RTCR - Total $ 174.71 -$ 174.71 $ $ 167.74 -$ 167.74 $ 

RTCR - Net Change $ 4.12 -$ $ 4.12 $ 3.80 -$ $ 3.80

Alternative Option - Total $ 187.50 -$ 187.50 $ $ 182.48 -$ 182.48 $ 

Alternative Option - Net Change $ 16.91 -$ $ 16.91 $ 18.54 -$ $ 18.54

1989 TCR - Total $ 3.87 -$ $ 3.87 $ 3.72 -$ $ 3.72

RTCR - Total $ 1.12 -$ $ 1.12 $ 1.09 -$ $ 1.09

RTCR - Net Change $ (2.75) -$ $ (2.75) $ (2.63) -$ $ (2.63)

Alternative Option - Total $ 0.78 -$ $ 0.78 $ 0.66 -$ $ 0.66

Alternative Option - Net Change $ (3.10) -$ $ (3.10) $ (3.06) -$ $ (3.06)

1989 TCR - Total $ 5.11 -$ $ 5.11 $ 4.92 -$ $ 4.92

RTCR - Total $ 4.88 -$ $ 4.88 $ 4.70 -$ $ 4.70

RTCR - Net Change $ (0.23) -$ $ (0.23) $ (0.22) -$ $ (0.22)

Alternative Option - Total $ 5.66 -$ $ 5.66 $ 5.59 -$ $ 5.59

Alternative Option - Net Change $ 0.54 -$ $ 0.54 $ 0.67 -$ $ 0.67

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Net Change -$ -$ -$ -$ -$ -$ 

Alternative Option - Total -$ -$ -$ -$ -$ -$ 

Alternative Option - Net Change -$ -$ -$ -$ -$ -$ 

1989 TCR - Total $ 1.13 0.21$ $ 1.34 $ 1.08 $ 0.20 $ 1.29

RTCR - Total $ 1.63 0.20$ $ 1.84 $ 1.57 $ 0.20 $ 1.77

RTCR - Net Change $ 0.51 $ (0.01) $ 0.50 $ 0.49 $ (0.01) $ 0.48

Alternative Option - Total $ 1.76 0.23$ $ 1.99 $ 1.72 $ 0.23 $ 1.94

Alternative Option - Net Change $ 0.63 0.02$ $ 0.65 $ 0.63 $ 0.02 $ 0.65

1989 TCR - Total $ 0.70 0.26$ $ 0.96 $ 0.68 $ 0.25 $ 0.92

RTCR - Total $ 0.90 0.19$ $ 1.08 $ 0.88 $ 0.18 $ 1.06

RTCR - Net Change $ 0.20 $ (0.07) $ 0.12 $ 0.20 $ (0.07) $ 0.13

Alternative Option - Total $ 1.26 0.29$ $ 1.55 $ 1.30 $ 0.31 $ 1.61

Alternative Option - Net Change $ 0.55 0.03$ $ 0.58 $ 0.62 $ 0.06 $ 0.68

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total $ 9.62 0.01$ $ 9.63 $ 8.14 $ 0.01 $ 8.15

RTCR - Net Change $ 9.62 0.01$ $ 9.63 $ 8.14 $ 0.01 $ 8.15

Alternative Option - Total $ 10.01 0.01$ $ 10.02 $ 8.52 $ 0.01 $ 8.53

Alternative Option - Net Change $ 10.01 0.01$ $ 10.02 $ 8.52 $ 0.01 $ 8.53

1989 TCR - Total -$ -$ -$ -$ -$ -$ 

RTCR - Total $ 2.82 0.00$ $ 2.82 $ 2.49 $ 0.00 $ 2.49

RTCR - Net Change $ 2.82 0.00$ $ 2.82 $ 2.49 $ 0.00 $ 2.49

Alternative Option - Total $ 3.78 0.01$ $ 3.79 $ 3.57 $ 0.01 $ 3.58

Alternative Option - Net Change $ 3.78 0.01$ $ 3.79 $ 3.57 $ 0.01 $ 3.58

1989 TCR - Total $ 3.75 0.44$ $ 4.19 $ 3.60 $ 0.42 $ 4.02

RTCR - Total $ 0.26 0.06$ $ 0.32 $ 0.25 $ 0.06 $ 0.31

RTCR - Net Change $ (3.49) $ (0.38) $ (3.86) $ (3.35) $ (0.36) $ (3.71)

Alternative Option - Total $ 0.35 0.08$ $ 0.43 $ 0.35 $ 0.08 $ 0.44

Alternative Option - Net Change $ (3.40) $ (0.36) $ (3.76) $ (3.25) $ (0.34) $ (3.58)

Notes: 

2) For modeling purposes, additional routine sample counts include regular routine samples taken in the same month.

Source: Final RTCR cost model.

Repeat Monitoring

Annual Site Visits

Level 1 Assessment

Level 2 Assessment

Corrective Actions based on Level 1 Assessments

Corrective Actions based on Level 2 Assessments

1) Detail may not add due to independent rounding. Because only the incremental costs of some rule components are considered as 

part of the cost analysis, references to “total” costs in this exhibit do not refer to the complete costs for regulatory implementation, 

but only to the specific costs considered to calculate net changes in costs. 

3% Discount Rate 7% Discount Rate

Rule Implementation and Annual Administration

Revising Sample Siting Plans

Routine Monitoring

Additional Routine Monitoring

Public Notification
Economic Analysis for the Final RTCR 9-26 September 2012 

Exhibit 9.13 Total and Net Change in Annualized Costs to PWSs by PWS Size and 

Type ($Millions, 2007$) 

1989 TCR - Total RTCR - Total RTCR - Net

Alternative 

Option - Total

Alternative 

Option - Net

1989 TCR - 

Total RTCR - Total RTCR - Net

Alternative 

Option - 

Total

Alternative 

Option - Net

A B C=B-A D E=D-A F G H=G-F I J=I-F

≤100 $7.4 $7.5 $0.1 $7.6 $0.2 $7.1 $7.3 $0.2 $7.5 $0.3

101-500 $9.0 $9.4 $0.4 $9.5 $0.5 $8.6 $9.1 $0.5 $9.2 $0.6

501-1,000 $3.7 $3.8 $0.0 $3.8 $0.1 $3.6 $3.7 $0.1 $3.7 $0.1

1,001-4,100 $13.2 $13.6 $0.4 $13.6 $0.4 $12.7 $13.1 $0.4 $13.1 $0.4

4,101-33,000 $42.4 $44.8 $2.4 $44.8 $2.4 $40.7 $42.8 $2.1 $42.8 $2.1

33,001-96,000 $34.9 $36.4 $1.5 $36.4 $1.5 $33.5 $34.8 $1.3 $34.8 $1.3

96,001-500,000 $34.7 $36.2 $1.5 $36.2 $1.5 $33.4 $34.6 $1.2 $34.6 $1.2

500,001-1 Million $6.5 $6.7 $0.2 $6.7 $0.2 $6.2 $6.4 $0.1 $6.4 $0.1

> 1 Million $5.6 $5.6 ($0.0) $5.6 ($0.0) $5.3 $5.3 ($0.0) $5.3 ($0.0)

Total $157.4 $163.9 $6.5 $164.1 $6.7 $151.3 $157.2 $5.9 $157.5 $6.2

≤100 $2.6 $2.7 $0.1 $3.7 $1.1 $2.5 $2.7 $0.2 $3.8 $1.4

101-500 $1.9 $2.0 $0.1 $2.8 $0.9 $1.8 $2.0 $0.2 $2.9 $1.1

501-1,000 $0.6 $0.6 $0.1 $0.9 $0.3 $0.6 $0.6 $0.1 $0.9 $0.3

1,001-4,100 $1.2 $1.3 $0.1 $1.3 $0.1 $1.1 $1.2 $0.1 $1.2 $0.1

4,101-33,000 $0.4 $0.5 $0.1 $0.5 $0.1 $0.4 $0.5 $0.0 $0.5 $0.0

33,001-96,000 $0.1 $0.1 $0.0 $0.1 $0.0 $0.1 $0.1 $0.0 $0.1 $0.0

96,001-500,000 $0.1 $0.1 ($0.0) $0.1 ($0.0) $0.1 $0.1 ($0.0) $0.1 ($0.0)

500,001-1 Million $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0

> 1 Million $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0 $0.0

Total $6.9 $7.3 $0.4 $9.3 $2.5 $6.6 $7.2 $0.6 $9.6 $3.0

≤100 $13.4 $18.7 $5.3 $28.1 $14.7 $12.8 $18.2 $5.3 $28.9 $16.1

101-500 $4.9 $6.5 $1.6 $9.5 $4.7 $4.7 $6.3 $1.6 $9.8 $5.1

501-1,000 $0.6 $0.8 $0.2 $1.2 $0.5 $0.6 $0.8 $0.2 $1.2 $0.6

1,001-4,100 $0.9 $1.0 $0.1 $1.0 $0.1 $0.9 $1.0 $0.1 $1.0 $0.1

4,101-33,000 $0.4 $0.5 $0.1 $0.5 $0.1 $0.4 $0.5 $0.0 $0.5 $0.0

33,001-96,000 $0.1 $0.1 ($0.0) $0.1 ($0.0) $0.1 $0.1 ($0.0) $0.1 ($0.0)

96,001-500,000 $0.1 $0.1 ($0.0) $0.1 ($0.0) $0.1 $0.1 ($0.0) $0.1 ($0.0)

500,001-1 Million $0.2 $0.2 ($0.0) $0.2 ($0.0) $0.2 $0.2 ($0.0) $0.2 ($0.0)

> 1 Million $0.3 $0.3 $0.0 $0.3 $0.0 $0.3 $0.3 $0.0 $0.3 $0.0

Total $20.9 $28.1 $7.3 $41.0 $20.1 $20.1 $27.3 $7.3 $42.0 $21.9

Grand Total $185.2 $199.3 $14.2 $214.4 $29.3 $177.9 $191.7 $13.8 $209.0 $31.1

Source: Final RTCR cost model.

Note: Detail may not add due to independent rounding. Because only the incremental costs of some rule components are considered as part of the cost analysis, references to total costs in 

this exhibit do not refer to the complete costs for regulatory implementation, but only to the specific costs considered to calculate net changes in costs. 

PWS Size

(Population

Served)

3% Discount Rate 7% Discount Rate

Community Water Systems (CWSs)

Nontransient Noncommunity Water Systems (NTNCWSs)

Transient Noncommunity Water Systems (TNCWSs)

9.1.3 Comparison of National Benefits and Costs of the Regulatory Options Considered 

Because the potential benefits of the RTCR and Alternative option have not been 

monetized, direct questions of how benefits compare to costs cannot be quantitatively answered 

(i.e., whether monetary benefits exceed costs and by how much). However, EPA’s collective 

evaluation of the results presented in this EA lead to the conclusion that the benefits of the 

RTCR will, in fact, exceed costs. Further evaluation of the cost effectiveness of the RTCR in 

comparison to the Alternative option considered is provided in Section 9.3. The break-even 

analysis described in Section 9.3.2 entails determining how many cases of morbidity and/or 

mortality would need to be avoided in order for the benefit of those avoided cases to equal the 

cost of the rule option. It does not predict cases of illness avoided as a result of the rule. Instead, 

it is included to help provide some context for considering the magnitude of cases of waterborne 

illness that would need to be avoided to break-even with rule costs. 
Economic Analysis for the Final RTCR 9-27 September 2012 

9.2 Effect of Uncertainties and Non-quantified Benefit/Cost Estimates on the Estimation 

of National Benefits and Costs 

Throughout the development of the analyses in this EA, EPA closely evaluated 

uncertainties in data used. EPA presents a discussion and comprehensive list of assumptions that 

introduce uncertainty into the analysis in Sections 4.5 and 5.3.3.1 (Exhibits 4.13 and 5.22a-b, 

respectively). Certain assumptions are incorporated into the predictive model for all three 

regulatory options in a similar fashion (1989 TCR as well as the RTCR and Alternative option). 

Because the analysis is based on net changes from the 1989 TCR to the RTCR and Alternative 

option, incorporating these uncertainties into the 1989 TCR and the options results in no 

significant net effect on the analysis results. As discussed in Chapters 4 and 5, although GWR 

assumptions are considered by EPA to be conservative estimates of the effectiveness of the 

GWR, they are incorporated into the model in similar fashion for all three regulatory options 

considered, and therefore are not expected to significantly affect net results of the EA. However, 

assumptions for certain variables identified as key drivers in producing the net results of this EA 

(the frequency and effectiveness of corrective actions) affect the RTCR and Alternative option 

but not the 1989 TCR. These assumptions are further evaluated in a sensitivity analysis in Ch. 5, 

which is summarized in Section 9.2.1. 

EPA also assessed non-quantified costs and benefits to estimate how they would affect 

the overall conclusions of the analyses performed. Potential impacts of non-quantified costs and 

benefits are discussed in Chapter 7 and Chapter 6, respectively, of the EA. Section 9.2.2 

summarizes the major non-quantified costs and benefits evaluated. 

9.2.1 Summary of Major Uncertainties in EA Analyses 

The primary sources of uncertainty in the RTCR are introduced into the analysis in the 

occurrence model and cost model. In the occurrence model, uncertainty is introduced in two 

types of information. First, data on TC/E. coli occurrence and acute and non-acute violations 

data are adapted from the Six-Year Review and Safe Drinking Water Information 

System/Federal Version. Second, EPA used best professional judgment and stakeholder input in 

choosing the values of model inputs to represent the net increase in effective corrective actions to 

be implemented under the RTCR, and the resulting period of reduced occurrence (both in length 

of time and percent reduction). The data limitations are discussed in Chapter 4 of this EA. The 

influence of selected inputs on the model output was tested in a sensitivity analysis, using 

substitute values that were factors of 0.5 and 2.0 of the original values. Model runs based on the 

0.5 decrease in original inputs yielded results that decreased by a factor less than 0.5 (i.e., the 

results were between 0.5 and 1.0 of the original value). Similarly, model runs based on inputs 

that were two times the value of the original inputs yielded results that were less than a multiple 

of two times the original output. These results, showing that input variable selection has less than 

a one-to-one influence on model output, indicate that the model output is not highly sensitive to 

changes in these input variables. 

Additionally, uncertainty in the analysis results stemmed from the complexity of 

interactions between the effects of the various rule components. The occurrence model produced 

outputs that showed a decrease in acute violations under the RTCR and an increase under the 

Alternative option. Given that the Alternative option incorporated the same risk reducing 
Economic Analysis for the Final RTCR 9-28 September 2012 

features (assessments and corrective actions) as the RTCR, EPA considered that the additional 

sampling under the Alternative option was having a larger upwards effect (increase) on 

occurrence compared to the downward effect of the additional corrective actions. EPA developed 

a stepwise sensitivity analysis to test the relative importance of the following competing effects 

under the RTCR relative to the 1989 TCR: 

 New assessments and corresponding corrective actions. 

 Reduced repeat and additional routine monitoring. 

The results (Section 6.4) revealed that acute violations under the RTCR as compared to 

the 1989 TCR differed as follows: 

 Many acute violations were prevented from occurring by implementation of 

assessments and corresponding corrective actions. 

 Some acute violations were missed by the reduction in repeat and additional routine 

sampling. 

From these results (described in Section 6.4), EPA concluded that under the RTCR, more 

acute violations are prevented than are missed. Additionally, the increase in routine monitoring 

under the RTCR finds additional acute violations as compared to the 1989 TCR, which explains 

the net increase in the acute violations found as compared to the 1989 TCR. Exhibits 9.2–9.7 

show the larger net difference (between the alternative and baseline) seen in levels of acute 

violations, non-acute violations, and corrective actions implemented under the RTCR as 

compared to the Alternative option. 

The sources of uncertainty embedded within the results of the occurrence model are also 

incorporated into the cost model. As described in reference to the occurrence model, EPA used 

best professional judgment and stakeholder input in choosing 10% as the factor of net increase 

over corrective actions implemented under the 1989 TCR. A sensitivity analysis of the effect of 

an increase in this factor on costs revealed that as the number of corrective actions increases, a 

portion of the corresponding cost is offset by the reduced number of assessments required as 

water quality improves (Section 7.7 of this EA). 

A potentially significant additional source of uncertainty in costs is introduced in the 

distribution of corrective actions selected (i.e., the number of each type implemented) for the 

10% additional corrective actions. Because there is a wide variation in the unit costs of the actual 

corrective actions underlying the compliance forecast (see Appendix D for unit cost detail), EPA 

ran two sensitivity analyses to assess the potential impacts of a high and low cost distribution in 

the compliance forecast. The results provide a low bound and a high bound on the original 

analysis results: approximately $3 million/$25 million for the RTCR and $17 million/$43 million 

for the Alternative option (at 3 percent discounting). This indicates that although the estimates of 

the number of systems that would choose each type of corrective action has a significant impact 

on costs of the rule, the rule remains a relatively low cost rule under the most conservative 

(costly) assumptions. 
Economic Analysis for the Final RTCR 9-29 September 2012 

9.2.2 Summary of Non-quantified Costs and Benefits 

EPA believes that all of the rule elements that are the major drivers of the net change in 

costs from the 1989 TCR have been quantified to the greatest degree possible. However, cost 

reductions related to fewer monitoring and reporting violations are not specifically accounted for 

in the cost analysis, and their exclusion from consideration may result in an overestimate of net 

change in cost between the 1989 TCR and the RTCR or Alternative option. Using E. coli as the 

endpoint, benefits have been estimated and predictions made about the reduced hazard associated 

with reduced exposure to fecal contamination and the potential benefits from corrective actions 

that, if effective, will reduce exposure. No attempt was made to monetize these benefits by 

predicting infections, illnesses or deaths and to compare these values directly with the monetized 

costs because of lack of data. 

Because the cost analyses in this EA focus on net changes in costs, consideration of nonquantified costs can result in either an under- or overestimate of the net costs for the RTCR, as 

described in Section 7.7 of this EA. Overall, the non-quantified costs identified would potentially 

lower the net cost of the RTCR, and include the following: 

 Reduced costs due to overlap between sanitary surveys and required assessments; 

and

 Reductions in costs related to less frequent PN for reporting and monitoring 

violations. 

Additionally, EPA identified a potential cost and benefit increase for the RTCR and 

Alternative option related to the baseline assumption that all PWSs are currently meeting 

requirements of the TCR. To the degree that PWSs are not currently meeting TCR requirements, 

the 1989 TCR costs and benefits are overstated in the RTCR EA, resulting in an underestimate of 

the net change in costs and benefits under the RTCR. 

EPA identified five additional potential areas of non-quantified benefits: 

 Reductions in primary and secondary endemic disease burden, both acute and 

chronic, associated with consuming PWS drinking water; 

 Reductions in risk of outbreak and associated illness and costs; 

 Benefits from increased operator knowledge about their systems (including more 

consistent water quality); 

 Accelerated infrastructure repair/replacement; and 

 Reductions in averting behavior (due to higher consumer confidence in water 

quality). 

Taken together, these items represent a potential for significant additional health benefits. 

For the first four items listed, benefits may be realized directly through the elimination, 

reduction, and/or prevention of pathogen occurrence. Reductions in averting behavior may lead 
Economic Analysis for the Final RTCR 9-30 September 2012 

to benefits related to a more efficient use of resources (i.e., using tap water instead of more 

expensive, yet not necessarily safer, alternatives). 

9.3 Comparison of the Regulatory Options Considered 

The following subsections present further analysis of the RTCR in comparison to the 

Alternative option. Comparisons based on the net change in costs and benefits and several 

effectiveness measures are presented to inform the selection of the RTCR over the Alternative 

option. 

9.3.1 Net Change in Costs and Benefits 

The net change in costs and benefits are those that are incurred or realized to reduce 

pathogen illnesses and deaths from one option to the next more stringent option. Estimates of the 

net change in costs and benefits are useful when considering the economic efficiency of different 

regulatory options considered by EPA. One goal of this analysis is to identify the regulatory 

option where net social benefits are maximized. Net benefits analysis is not possible when 

benefits are not monetized as in the case with the RTCR. However, this type of analysis can still 

provide information on relative cost-effectiveness of different regulatory options. 

For the RTCR only costs were monetized. An indirect proxy for benefits was quantified. 

Performance of corrective actions is expected to have an impact that is most directly translatable 

into potential health benefits. Therefore, to compare the additional cost increases and associated 

net benefits of the RTCR and Alternative option, benefits are presented in terms of corrective 

actions performed. Specifically, only Level 2 corrective actions are considered because they are 

performed in response to a Level 2 treatment technique trigger, which includes either an E. coli

MCL violation or a second Level 1 treatment technique trigger within a 12-month period. 

Corrective actions performed in response to Level 2 triggers are, therefore, considered more 

indicative of addressing a public health problem than actions addressing a Level 1 trigger. 

To compare the additional cost increases and associated benefits (shown as numbers of 

Level 2 corrective actions performed) of the RTCR and Alternative option, analyses of both the 

net change in costs and benefits are presented in Exhibit 9.14. Note, the RTCR net change in 

costs presented in Exhibits 9.14 to 9.17 represents the additional costs between the 1989 TCR 

and RTCR, the Alternative option net change in costs represent the additional costs between the 

RTCR and Alternative option. 

Exhibit 9.14 shows that the annualized net change in costs for the Alternative option 

compared to the RTCR are similar to the annualized net change in costs for the RTCR compared 

to the 1989 TCR ($15.3 million vs. $14.3 million, using a 3% discount rate). Consistent with the 

lower net change in costs, the net change in benefits in terms of Level 2 corrective actions 

performed are fewer under the Alternative option than under the RTCR. The new requirement 

under both the RTCR and Alternative option for PWSs to implement assessments and corrective 

actions will capture the bulk of improvements to be made in comparison to the 1989 TCR. Also, 

the additional sampling required under the Alternative option relative to the RTCR provides an 

approximately equal increase in costs but a lower net effectiveness relative to the portion of 

incurred costs. This suggests that beyond a certain level of corrective action implementation, 
Economic Analysis for the Final RTCR 9-31 September 2012 

PWSs would experience diminishing net marginal returns for their investment in correction 

actions. The relationship between the net change in costs and benefits is examined further with 

respect to cost effectiveness in Section 9.3.2. 

Exhibit 9.14 Net Change in Annualized Present Value Costs ($Millions, 2007$) and 

Benefits (Number of Level 2 Corrective Actions) 

3 % 7 % 3% 7%

1989 TCR $ 186.1 $ 178.8 No change3 No change3

RTCR $ 200.4 $ 193.0 208 202

RTCR - Net Change1 $ 14.3 $ 14.2 208 202

Alternative Option $ 215.7 $ 210.5 336 355

Alternative Option - Net Change2 $ 15.3 $ 17.5 128 153

Benefits

(L2 Corrective Actions)

1Represents the net change of the RTCR over the 1989 TCR.

2Represents the net change of the Alternative option over the RTCR. Add net change for Alternative option to net change for RTCR to calculate the total net 

change of the Alternative option over the 1989 TCR. Note: The RTCR occurrence model yields the number of corrective actions that are expected to be 

implemented in addition to (net of) those already implemented under the 1989 TCR. The model does not incorporate an estimate of the number of corrective 

actions implemented per year under the 1989 TCR and does not yield a total for the RTCR and Alternative option that includes the 1989 TCR corrective actions. 

Benefits shown include corrective actions based on L2 assessments. Detailed benefits and cost information is provided in Appendices A and C, respectively, 

of the Final RTCR EA (USEPA 2009a).

3As explained in section VI.F.2.f of the preamble, for modeling purposes, EPA estimates the net change only in the number of corrective actions performed 

under the RTCR and Alternative options compared to the 1989 TCR and thus did not quantify the (non-zero) baseline number of corrective actions performed 

under the 1989 TCR.

Regulatory Option Costs

9.3.2 Cost Effectiveness Measures 

To further differentiate between the RTCR and Alternative option results, EPA 

performed analyses to assess the cost effectiveness of each regulatory option. In this section, 

EPA provides an estimate of the cost per corrective action performed under the regulatory 

options, which is a measure of the cost effectiveness of each rule option. As noted elsewhere in 

this chapter, corrective actions are considered a clear enhancement to the efforts to reduce E. coli

(and co-occurring pathogen) occurrence in PWSs, and the most direct benefit in this EA. 

Corrective actions are also a main driver of the net increases in costs for both rule options 

considered. In addition, the modeling of corrective actions is done only on a net basis relative to 

the level performed under the 1989 TCR, thus providing a clear dividing line between impacts 

under the 1989 TCR and each rule option. As shown in Exhibit 9.15, the annual net cost of the 

rule per corrective action performed beyond the baseline is approximately $0.02 million and 

$0.04 million (3% discount rate) for the RTCR and Alternative option, respectively. 
Economic Analysis for the Final RTCR 9-32 September 2012 

Exhibit 9.15 Total Net Annual Cost Per Corrective Action Implemented under 

RTCR and Alternative Option, Annualized Using 3% and 7% Discount Rates 

($Millions, 2007$) 

Regulatory Option 3% Discount Rate 7% Discount Rate

RTCR - Net Change $ 14.3 $ 14.2

RTCR - Incremental Number of Corrective Actions (L1 & L2) 616 594

1 RTCR - Cost Effectiveness Analysis $ 0.02 $ 0.02

Alternative Option - Net Change $ 29.6 $ 31.7

Alternative Option - Incremental Number of Corrective Actions (L1 & L2) 808 819 1 Alternative Option - Cost Effectiveness Analysis $ 0.04 $ 0.04

Notes:

1

CEA = (Net Change)/(Incremental Number of corrective actions).

2

Detailed cost information is provided in Appendix C.

EPA also considered the net cost effectiveness of the RTCR for the entire population of 

PWSs taken as a whole as compared to the Alternative option to determine the additional benefit 

associated with that portion of Alternative option cost beyond the cost of the RTCR. Exhibit 9.16 

shows that the RTCR has a far lower marginal cost per corrective action for PWSs than the 

Alternative option ($0.02 million for the RTCR vs. $0.08 million for the Alternative option). 

This indicates that the additional corrective actions performed under the Alternative option are 

much more costly on a unit basis than those performed under the RTCR. 

EPA further considered the issue of additional costs under the Alternative option as 

compared to the RTCR in terms of the effect on small TNCWSs using GW (serving ≤100). The 

additional net change in costs under the Alternative option could cause substantial additional 

burden on small TNCWSs, which incur the largest portion of costs of the rule among all 

categories of systems. However, these same TNCWSs would also receive the most benefits from 

the RTCR (increased assessments and corrective actions following a trigger). EPA considered 

the group of 60,200 TNCWSs using GW (serving ≤100), which are the largest subset of systems 

by size/type, and which are expected to bear the highest burden of all system categories under 

the RTCR. Exhibit 9.17 shows that the net cost effectiveness of the RTCR is significantly greater 

than of the Alternative option (a cost per corrective action of $0.02 million vs. $0.07 million, 

respectively) and both options are more cost effective for this subset (TNCWSs using GW 

serving ≤100) than for the entire population of PWSs taken as a whole. The two net change cost 

analyses indicate that, using a 3 percent discount rate to compare incremental benefits and costs, 

the RTCR is significantly more cost effective (by a factor of approximately 3.9) than the 

Alternative option for the most burdened subset of systems, and is significantly more cost 

effective (by a factor of approximately 3.4) than the Alternative option when considering all 

PWSs together. 
Economic Analysis for the Final RTCR 9-33 September 2012 

Exhibit 9.16 Annualized Net Change in Costs per Corrective Action Implemented 

for All PWSs under RTCR and Alternative Option ($Millions, 2007$) 

Regulatory Option 3% Discount Rate 7% Discount Rate

RTCR - Net Change $ 14.30 $ 14.17

RTCR - Incremental Number of Corrective Actions (L1 & L2)1 615.82 593.71

RTCR - Incremental Cost per Corrective Action ($) $ 0.02 $ 0.02

Alternative Option - Net Change (over RTCR)2 $ 15.29 $ 17.52

Alternative Option - Incremental Number of Corrective Actions (L1 & L2) (over RTCR)2

 192.23 224.93

Alternative Option - Incremental Cost per Corrective Action ($) $ 0.08 $ 0.08

Notes:

1Exhibit includes the number of corrective actions predicted by the RTCR occurrence model to be implemented in addition to those 

implemented under the 1989 TCR. 

2Add net values for Alternative option to net values for RTCR to calculate total net values of Alternative option over 1989 TCR.

3Detailed cost information is provided in Appendix C.

Exhibit 9.17 Annualized Net Change in Costs per CA Implemented for TNCWSs 

(Serving <100 people) under RTCR and Alternative Option ($Millions, 2007$)

Regulatory Option 3% Discount Rate 7% Discount Rate

RTCR - Net Change $ 5.3 $ 5.3

RTCR - Incremental Corrective Actions (L1 & L2)1 287 275

RTCR - Incremental Cost per Corrective Action ($) $ 0.02 $ 0.02

Alternative Option - Net Change (over RTCR)2 $ 9.4 $ 10.8

Alternative Option - Incremental Corrective Actions (L1 & L2) (over RTCR)2

132 155

Alternative Option - Incremental Cost per Corrective Action ($) $ 0.07 $ 0.07

Notes: 

1Derived by dividing incremental rule costs applicable to TNCWS <100 by the incremental number of corrective actions to be implemented 

under the RTCR (relative to baseline) and the Alternative option (relative to the RTCR) by TNCWSs using GW.

2Add net values for Alternative option to net values for RTCR to calculate total net values of Alternative option over 1989 TCR. 

3Detailed cost information is provided in Appendix C.

9.3.3 Break-Even Analysis 

As described in Chapter 6 of this EA, this analysis does not include a fully quantified risk 

assessment because there are insufficient data on the co-occurrence in PWSs of fecal indicator E. 

coli and pathogenic strains of E. coli or other bacteria, viruses, and parasitic protozoa that can 

cause waterborne disease. Given the absence of E. coli and waterborne pathogen co-occurrence 

data to predict health effects in PWSs, EPA developed a break-even analysis to inform the 

discussion of whether the benefits justify the costs of the regulation. A break-even analysis 

typically compares the rule cost with the estimated value of the medical cases (and related costs 

such as time off from work) that would be avoided annually by the rule to determine if the rule 

benefits break even with avoided costs. In the case of the EA, where cases avoided cannot be 

estimated, the break-even analysis informs the benefit/cost discussion by providing estimates of 

the number of fatal and non-fatal cases that the rule would need to avoid in order to break even 

with rule costs. 

The underlying question this analysis seeks to inform is whether corrective actions 

performed under the RTCR will sufficiently reduce potential exposure to fecal contamination 

and/or waterborne pathogens to compensate for the net costs of the rule. One result of the 
Economic Analysis for the Final RTCR 9-34 September 2012 

implementation of the RTCR predicted by the model and presented in Exhibit 6.5 is that some 

number of acute events will be prevented.64 As discussed in Chapter 6, sufficient data are not 

available to quantify the numbers of illnesses and deaths potentially avoided by preventing such 

acute events. However, the presence of E. coli in a water system is an indicator of the presence 

of fecal contamination;65 it suggests that a pathway for the introduction of waterborne pathogens 

may exist. The total numbers of acute events and potentially affected people are small (most 

events are predicted in small NCWSs), but nonetheless there will be a positive impact on public 

health by avoiding these events. The magnitude of this impact will depend heavily on the 

specific elements underlying any acute event avoided: who and how many in the population are 

affected, and the etiologic agent to which exposure is avoided. An event can be endemic to a 

single person or small group of persons, or it may reach the level of an outbreak. The cause of an 

event may be one or more of a range of bacterial, viral, or parasitic organisms, as described in 

Chapter 2 of this EA. Although there may be a range of waterborne pathogens mitigated by 

implementation of the RTCR, two potential waterborne pathogens are considered in this analysis 

to provide input for developing the break-even analysis: shiga toxin-producing E. coli O157:H7 

(STEC O157)66 and Salmonella.

67

The Centers for Disease Control and Prevention (CDC) estimates that STEC O157 

pathogens from all sources are responsible for approximately 73,000 illnesses in the United 

States annually. The CDC has found that 15% of outbreak cases of STEC 0157 are waterborne 

(Rangel et al., 2005); if that rate applies as well to endemic cases, then approximately 11,000 

cases of STEC 0157 infection would be due to waterborne exposure. For Salmonella infections, 

the Economic Research Service (ERS) uses an estimate of 1,397,187 cases annually based on 

1999 estimates from the CDC that included an estimate of non-reported illnesses. The 1999 

estimate stated that the share of cases due to consumption of contaminated food was 95 percent, 

indicating that approximately 70,000 cases were due to other sources. While the portion of these 

cases due to waterborne exposure is unknown, some public systems have documented cases of 

waterborne Salmonellosis. In March of 2008, Salmonella in the water system of Alamosa, 

Colorado caused an outbreak in which hundreds of the 10,000 residents were sickened and one 

person died. The deep mountain aquifer from which the water was drawn was confirmed not to 

be the source of the bacteria (Berg, 2008), but two storage tanks had several inches of sediment 

 

64Results presented in Exhibit 6.5 of this EA indicate that fewer E. coli positive events would occur under the RTCR 

than under the 1989 TCR. These results are consistent with the net improvement in PWS water quality (as indicated 

by a decrease in fecal indicator E. coli) suggested by the stepwise analysis presented in Section 6.4 of this EA. 

Chapter 6 of the EA presents this information in further detail. 

65 Standridge, J. (2008) discusses the use of E. coli as an indicator of drinking water quality. 

66 According to the website of the American Academy of Family Physicians 

(http://www.aafp.org/afp/20000401/tips/11.html), “Shiga toxin-producing Escherichia coli is a group of bacteria 

strains capable of causing significant human disease. The pathogen is transmitted primarily by food and has become 

an important pathogen in industrialized North America. The subgroup enterohemorrhagic E. coli includes the 

relatively important serotype O157:H7, and more than 100 other non-O157 strains.”

67 Salmonella, according to the CDC website, is actually a group of bacteria that can cause diarrheal illness in 

humans. They are microscopic living creatures that pass from the feces of people or animals to other people or other 

animals. Salmonella serotype Typhimurium, which caused the 2008 Alamosa, CO outbreak, and Salmonella

serotype Enteritidis are the most common in the United States. Every year, approximately 40,000 cases of 

salmonellosis are reported in the United States; most of these are foodborne, but some, as in the case of Alamosa, 

are waterborne. (http://www.cdc.gov/nczved/dfbmd/disease_listing/salmonellosis_gi.html#2, downloaded 10-6-09)
Economic Analysis for the Final RTCR 9-35 September 2012 

and breaches, and one tank had breaches large enough for birds and animals to enter (CDPHE, 

2009). 

For the break-even analysis, medical cases are classified as non-fatal or fatal, and 

analyses are presented for these two classifications.68 The valuations for medical cases used in 

the break-even analysis are developed using the ERS Foodborne Illness Calculator69 (ERS 

Foodborne Illness Calculator), as described in Appendix E of the RTCR, for the two example 

pathogens considered: STEC O157 and Salmonella. For most ERS calculator inputs, default or 

suggested alternative values are used to estimate costs. However, for the valuation of fatal cases 

within the model, EPA used a value of a statistical life (VSL)70 estimate of $8.8 million71 to be 

consistent with EPA methodology for calculating the value of this measure.72

To represent a range of estimates, EPA used the ERS calculator to calculate break-even 

thresholds for a low- and high-end valuation of cases avoided corresponding to “traditional” and 

“enhanced” methodologies for estimating Cost of Illness (COI) values. For the traditional COI 

valuation, EPA used the ERS calculator default values for STEC O157, with the exception of the 

VSL applied to fatalities, which EPA updated as shown in Appendix E of the RTCR EA. To 

estimate an enhanced COI valuation, EPA applied the basic settings used for the traditional COI 

valuation (including the EPA-updated VSL value) but with alternative values for estimated 

productivity and disutility losses. The traditional COI, as developed in this analysis based on the 

default setting in the ERS calculator, places no value on lost nonmarket work time, while the 

enhanced COI method values nonmarket work time based on opportunity costs (equivalent to 

market work time lost). The alternative valuation used (a suggested option within the calculator) 

is to apply the productivity losses to all lost time for market and non-market work (e.g., for 

individuals who stay home to raise children or care for the elderly). The ERS calculator default 

 

68 Evaluation of fatal cases in this analysis includes consideration of the underlying non-fatal component of the 

illness prior to death. 

69 A full detailed description of the ERS Foodborne Illness Calculator, including detailed discussion of the items 

discussed previously and derivation of the underlying values used in calculations can be found online at: 

http://www.ers.usda.gov/Data/FoodborneIllness/ecoli_Intro.asp. 

70 The VSL represents an estimate of the monetary value of reducing risks of premature death. The VSL, therefore, 

is not an estimate of the value of saving a particular individual’s life. The value of a “statistical” life represents the 

sum of the values placed on small individual risk reductions across an exposed population. For example, if a 

regulation were to reduce the risk of premature death by 1/1,000,000 for one million exposed individuals, the 

regulation would “save” one statistical life (1,000,000 X 1/1,000,000). If each of the 1,000,000 people were willing 

to pay $5 to achieve the risk reduction anticipated from the regulation, the VSL would be $5 million ($5 X 

1,000,000). Appendix E of this EA provides further detail of the derivation of the updated VSL estimate. 

71 An EPA study characterized the range of possible VSL values as a Weibull distribution with a mean of $4.8 

million (1990 price level) based on 26 individual study estimates (USEPA, 1997). This represents the value 

recommended for use in benefits analyses in EPA’s Guidelines for Preparing Economic Analyses (USEPA, 2000) 

and endorsed by the Science Advisory Board (SAB) Arsenic review panel (USEPA, 2001a). For use in the breakeven analysis, adjustments to the base value from the EPA study were made to account for income and price level 

changes over time. The mean VSL, after all adjustments were made, was $8.8 million in year 2007 dollars. These 

adjustments are explained further in Appendix E of this EA. 

72 Use of different VSL estimates corresponding to different government agency policy and methodologies is 

specifically suggested by ERS, and EPA’s methodology is given as a specific example of an alternate value that may 

be used. 
Economic Analysis for the Final RTCR 9-36 September 2012 

value is zero for other forms of disutility caused by the illness,73 including pain and suffering, 

inconvenience, and lost non-work time; this setting is used for the traditional approach in this 

analysis. The alternative valuation, used for the enhanced approach in this analysis (also a 

suggested option within the calculator), is based on values (greater than zero) used by the Food 

and Drug Administration. 

Exhibits 9.18 and 9.19 show the values calculated for avoided cases using the ERS 

Foodborne Illness Calculator for STEC O157 and Salmonella, as summarized previously in this 

section and described in Appendix E of this EA. In addition to separate calculations based on 

traditional and enhanced COI valuation methodologies, estimates are presented separately for 

non-fatal and fatal cases. 

Using the valuations per case as described, EPA estimated the numbers of cases needed 

to break even by dividing the total net cost of the RTCR by the values from Exhibits 9.18 and 

9.19. The resulting estimates of break-even thresholds are presented in Exhibit 9.20 and 9.21 

separately for non-fatal and fatal cases for STEC O157 and Salmonella, respectively. Estimates 

are presented using both three and seven percent discount rates. 

Exhibit 9.18 Average Estimated Value per STEC O157 Case Avoided (2007$) 

Traditional COI Enhanced COI

Non-fatal cases only $ 1,756 $ 5,269

Fatal cases only1 $ 8,820,401 $ 8,821,911

1 Calculations for fatal cases include the COI component for the 

underlying illness prior to death.

Notes: COI estimates derived using USDA ERS Foodborne Illness 

Cost Calculator: STEC O157:H7. Traditional COI estimates are based 

on ERS default values for all inputs except for the VSL estimate, for 

which EPA substituted its own estimate of approximately $8.8 million. 

Enhanced COI estimates are based on the same values except for the 

following changes: productivity losses are applied to all cases rather 

than just those employed in the formal market, and FDA disutility 

values are applied rather than the ERS default value of 0.

Case Description Value Per Case

 

73 Disutility is a specific category defined in the ERS calculator, as mentioned previously, to include: pain and 

suffering, inconvenience, and lost non-work time. 
Economic Analysis for the Final RTCR 9-37 September 2012 

Exhibit 9.19 Average Estimated Value per Salmonella Case Avoided (2007$) 

Traditional COI Enhanced COI

Non-fatal cases only $ 210 $ 1,397

Fatal cases only1 $ 8,802,998 $ 8,803,551

1 Calculations for fatal cases include the COI component for the underlying 

illness prior to death.

Notes: COI estimates derived using USDA ERS Foodborne Illness Cost 

Calculator: Salmonella. Traditional COI estimates are based on ERS 

default values for all inputs except for the VSL estimate, for which EPA 

substituted its own estimate of approximately $8.8 million. Enhanced COI 

estimates are based on the same values except for the following changes: 

productivity losses are applied to all cases rather than just those employed 

in the formal market, and FDA disutility values are applied rather than the 

ERS default value of 0.

Case Description Value Per Case

Exhibit 9.20 Estimated Annual Break-Even Threshold for Avoided Cases of 

STEC O157 

Non-fatal

cases only

Fatal 

cases

only1

Non-fatal

cases only

Fatal 

cases

only1

3% 8,000 1.6 17,000 3.4

7% 8,000 1.6 18,000 3.6

3% 3,000 1.6 6,000 3.4

7% 3,000 1.6 6,000 3.6

RTCR

1 Calculations for fatal cases include the non-fatal COI component for the 

underlying illness prior to death.

Notes: 

1) The number of cases needed to reach breakeven threshold calculated by 

dividing the net change in costs for the RTCR (Exhibit 9.11) by the average 

estimated value of avoided cases (Exhibit 9.18). E. coli O157:H7 illness is 

only an example of a pathogenic endpoint that could be used for this analysis. 

Use of additional pathogenic contaminants in addition to this single endpoint 

would result in lower threshold values. 

2) Detail may not add due to independent rounding. 

3) The breakeven threshold is higher using a 7% discount rate than a 3% 

discount rate under the Alternative option. This result is consistent with the 

costs of the Alternative option being higher using the 7% discount rate, which 

is caused by the frontloading of costs in the period of analysis, as explained 

further in Chapter 7 of the EA.

COI

Methodology

Discount 

Rate

Alternative Option

Traditional

COI

Enhanced COI
Economic Analysis for the Final RTCR 9-38 September 2012 

Exhibit 9.21 Estimated Annual Break-Even Threshold for Avoided Cases of 

Salmonella 

Non-fatal

cases only

Fatal 

cases

only1

Non-fatal

cases only

Fatal 

cases

only1

3% 68,000 1.6 141,000 3.4

7% 68,000 1.6 151,000 3.6

3% 10,000 1.6 21,000 3.4

7% 10,000 1.6 23,000 3.6

COI

Methodology

Discount 

Rate

RTCR Alternative Option

1

 Calculations for fatal cases include the non-fatal COI component for the 

underlying illness prior to death.

Notes: 

1) The number of cases needed to reach breakeven threshold calculated by 

dividing the net change in costs for the RTCR (Exhibit 9.11) by the average 

estimated value of avoided cases (Exhibit 9.19). Salmonella is only is only an 

example of a pathogenic endpoint that could be used for this analysis. Use of 

additional pathogenic contaminants in addition to this single endpoint would 

result in lower threshold values. 

2) Detail may not add due to independent rounding. 

3) The breakeven threshold is higher using a 7% discount rate than a 3% 

discount rate under the Alternative option. This result is consistent with the 

costs of the Alternative option being higher using the 7% discount rate, which 

is caused by the frontloading of costs in the period of analysis, as explained 

further in Chapter 7 of the EA.

Traditional

COI

Enhanced COI

The estimates shown in Exhibits 9.20 and 9.21 for STEC O157 and Salmonella, 

respectively, represent the number of fatal cases that would need to be avoided annually by the 

rule for its benefits and costs to society to be equal, or break even, with rule costs. Based on 

either example pathogen, the results show that both the RTCR and Alternative option would 

need to avoid a relatively small number of fatal cases annually to break even with the rule costs. 

Under the RTCR, approximately two deaths would need to be avoided annually using a 

3% discount rate based on consideration of the bacterial pathogen STEC O157. Alternatively, 

approximately 3,000 or 8,000 non-fatal cases, using the enhanced or traditional benefits 

valuations approaches,74 respectively, would need to be avoided to break even with the RTCR 

costs. As expected based on its costs, the Alternative option would require that a higher number 

of cases be avoided annually for that option to break even (between 100% and 113% more than 

the RTCR under the enhanced and traditional approaches, respectively). 

 

74 Both traditional and enhanced COI approaches count the value of the direct medical costs and of time lost that 

would been spent working for a wage, but differ in their assessment of the value of time lost that would be spent in 

nonmarket work (e.g. housework, yardwork, and raising children) and leisure (e.g. recreation, family time, and 

sleep). They also differ in their valuation of (other) disutility, which encompasses a range of factors of well being, 

including both inconvenience and any pain and suffering. A complete discussion of the traditional and enhanced 

COI approaches can be found in Appendix E. 
Economic Analysis for the Final RTCR 9-39 September 2012 

As Exhibit 9.21 shows, approximately two deaths would need to be avoided annually 

from a Salmonella infection for the RTCR to break even. The estimated number of non-fatal 

Salmonella cases that would need to be avoided to break even under RTCR is approximately 

10,000 or 68,000 cases under the enhanced and traditional benefits valuations approaches, 

respectively. As expected based on its costs, the Alternative option would require that a higher 

number of Salmonella cases be avoided annually for that option to break even (approximately 

110% more than the RTCR under either the enhanced or traditional approaches).

As the discussion presented in Chapter 2 of this EA describes, disease and deaths are 

attributable to drinking water contamination across the country. The CDC has found that 15% of 

outbreak cases of STEC O157 are waterborne (Rangel et al., 2005); if that rate applies as well to 

endemic cases, then approximately 11,000 cases would be due to waterborne exposure to STEC 

O157. The revised rule (RTCR) could mitigate pathways of contamination into PWSs and 

prevent some of these endemic cases. For only this one contaminant, if just 3,000 non-fatal cases 

under the enhanced COI approach, 8,000 non-fatal cases under the traditional COI approach, or 

approximately two fatal cases of STEC O157 are avoided annually by the RTCR, the rule would 

break even. If more than one contaminant was reduced or prevented from occurring in PWSs, the 

rule would be that much more likely to break even. Avoided illness and death from secondary 

transmission of infection could also be significant, and would increase the likelihood that total 

avoided cases reach a break-even threshold. An additional consideration is that a larger number 

of avoided cases would be predicted if all the benefits of the rule as described in Chapter 6 could 

be quantified in the analysis. If increased assessments and corrective actions result in a level of 

system knowledge that enables earlier mitigation of potential pathways of contamination, then 

additional illnesses or deaths may be avoided beyond those suggested by the decrease in acute 

events that the model predicts. In the case of the outbreak of Salmonella infections in Alamosa, 

Colorado, as described previously in this section of the EA, some of the key factors that 

contributed to the outbreak include significant levels of sediment and the presence of breaches to 

the integrity of the storage tank. These are two types of sanitary defects that could be identified 

in an assessment and eliminated by corrective action. 

9.3.4 Summary of Conclusions 

The preferred regulatory option for this rulemaking is the RTCR. The analyses performed 

as part of this EA support the collective judgment and consensus of the advisory committee that 

their AIP recommendations, as defined by the RTCR, provide for effective and efficient 

revisions to 1989 TCR regulatory requirements. The following is a summary of points that must 

be considered when weighing the benefits and costs of the rule options: 

 The estimated net cost of the RTCR is not only small relative to the 1989 TCR 

(approximately $14 million annually using either a 3% or 7% discount rate), but it 

is also small compared to the net cost increase of the Alternative option relative to 

the 1989 TCR (approximately $30–$32 million using a 3% and 7% discount rate, 

respectively) (exhibit 9.11). This cost differential is especially important 

considering the potential concentration of impacts on the smallest TNCWSs 

(exhibit 9.13) and the potential frontloading of costs under the Alternative option 

(exhibits 9.8–9.10). 
Economic Analysis for the Final RTCR 9-40 September 2012 

 The benefits are expected to be positive under the RTCR and no backsliding in 

overall risk is predicted (Section 9.1.1.1) from the 1989 TCR. The total benefits 

under the Alternative option would be greater than under the RTCR (Section 

9.1.1.2), but the RTCR is more cost effective both on an average basis and based on 

the net change in costs (Exhibits 9.15–9.17). 

– Of the various outputs of the occurrence and cost models developed in this 

EA, the estimate of corrective actions to be implemented has the clearest 

connection to potential benefits. Based on this metric, the RTCR is more 

cost effective on average (i.e., costs less per corrective action achieved) 

than the Alternative option (Exhibit 9.15) by a factor of approximately 1.6. 

– EPA conducted a net cost effectiveness analysis based on the increasing 

stringency of the options from the 1989 TCR to the RTCR to the 

Alternative option. In comparing the ratio of additional costs and benefits 

associated with the RTCR compared to the 1989 TCR and of the 

Alternative option compared to the RTCR, EPA found the following 

results: 

 Exhibit 9.16 shows that the net cost effectiveness of the RTCR far 

exceeds that of the Alternative option for the entire population of 

PWSs when taken as a whole, by a factor of approximately 3.4. 

 Exhibit 9.17 shows that for TNCWSs the cost effectiveness of the 

RTCR far exceeds that of the Alternative option, by a factor of 

approximately 3.9. 

 Although data limitations precluded estimating the number of fatal or non-fatal 

illnesses that would be avoided by implementation of the regulatory options 

considered, the break-even analysis (Section 9.3.3) shows that approximately two 

deaths would need to be avoided annually for the final rule to break even based on 

estimated net costs (exhibit 9.20) using a three percent discount rate. Considering 

the average costs of non-fatal illnesses resulting from STEC O157 infection, the 

RTCR would break even if it avoided 3,000 or 8,000 such cases annually based on 

the enhanced or traditional cost of illness approach, respectively. These thresholds 

under the Alternative option are 100% to 113% more than under the RTCR using 

the enhanced and traditional approaches. Under the RTCR, the estimated breakeven threshold for non-fatal Salmonella cases is 10,000 or 68,000 annually for the 

enhanced and traditional approaches, respectively, and approximately 110% more 

(using either the enhanced or traditional approach) for the Alternative option. These 

break-even thresholds would be reduced if more than one type of pathogen is 

avoided through implementation of the RTCR, or if cases of secondary transmission 

are avoided, both of which are logical extensions of the benefits. Given the large 

variety of pathogens that may occur in PWS source water and the relatively low net 

costs of the RTCR, EPA believes the RTCR is likely to at least break even. 
Economic Analysis for the Final RTCR 9-41 September 2012 

 There are several items that are not quantified in the EA that represent a potential 

for significant additional benefits (Section 9.2.2). These additional benefits may be 

realized due to reductions in co-occurring contaminants, increased systems 

knowledge (including more consistent water quality), reductions in outbreak risks, 

accelerated infrastructure repair/replacement, and reductions in averting behavior 

(due to higher consumer confidence in water quality). 

As a result of these considerations, EPA believes that the estimated benefits of the RTCR 

as defined by the RTCR will likely exceed the modest increases in annualized national costs and 

will be effective in reducing risk to consumers from exposure to fecal contamination in drinking 

water.
Economic Analysis for the Final RTCR 10-1 September 2012 

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