United States Environmental Protection Agency

Environmental Regulations and Technology

Control of Pathogens and Vector Attraction in Sewage Sludge

EPA/625/R-92/013 Revised July 2003

Environmental Regulations and Technology

Control of Pathogens and Vector Attractionin Sewage Sludge

(Including Domestic Septage) Under 40 CFR Part 503

This guidance was prepared by

U.S. Environmental Protection AgencyOffice of Research and Development

National Risk Management Research Laboratory Center for Environmental Research Information

Cincinnati, OH 45268

R ec yc led/R ec yc lable P rinted with vegetable-based ink on paper that contains a minimum of 50% pos t-consumer fiber content processe d chlorine free.

Notice

This report has been reviewed by the U.S. Environmental Protection Agency and approved for publication. The process alternatives, trade names, or commercial products are only ex­amples and are not endorsed or recommended by the U.S. Environmental Protection Agency. Other alternatives may exist or may be developed.

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Foreword

The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the Nation’s land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to formulate and implement actions leading to a compatible balance between human activities and the ability of natural systems to support and nurture life. To meet this mandate, EPA’s research program is providing data and technical support for solving environmental problems today and building a science knowledge base necessary to manage our ecological resources wisely, understand how pollutants affect our health, and prevent or reduce environmental risks in the future.

The National Risk Management Research Laboratory (NRMRL) is the Agency’s center for investigation of technological and management approaches for preventing and reducing risks from pollution that threaten human health and the environment. The focus of the Laboratory’s research program is on methods and their cost-effectiveness for prevention and control of pollution to air, land, water, and subsurface resources; protection of water quality in public water systems; remediation of contaminated sites, sediments and ground water; prevention and control of indoor air pollution; and restoration of ecosystems. NRMRL collaborates with both public and private sector partners to foster technologies that reduce the cost of compliance and to anticipate emerging problems. NRMRL’s research provides solutions to environmental problems by: developing and promoting technologies that protect and improve the environment; advancing scientific and engineering information to support regulatory and policy decisions; and providing the technical support and information transfer to ensure implementation of environmental regulations and strategies at the national, state, and community levels.

This publication has been produced as part of the Laboratory’s strategic long-term research plan. It is published and made available by EPA’s Office of Research and Development to assist the user community and to link researchers with their clients.

Hugh W. McKinnon, Director National Risk Management Research Laboratory

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Contents

Chapter 1 Introduction ..................................................................................................................... 11.1 What is Sewage Sludge? .................................................................................................. 11.2 U.S. Regulation of Treated Sewage Sludge (Biosolids) ..................................................... 41.3 Implementation Guidance .................................................................................................. 41.4 Definitions ......................................................................................................................... 51.5 Pathogen Equivalency Committee ..................................................................................... 61.6 What is in this Document? ................................................................................................ 6

Chapter 2 Sewage Sludge Pathogens ............................................................................................. 82.1 What are Pathogens? ..................................................................................................... 82.2 Pathogens in Sewage Sludge .......................................................................................... 82.3 General Information on Pathogens .................................................................................. 102.4 Protecting Public Health -The Part 503 ........................................................................... 112.5 Frequently Asked Questions ........................................................................................... 16

Chapter 3 Overview of Part 503 Subpart D Requirements, Their Applicability, and Related Requirements ................................................................................................. 20

3.1 Introduction ..................................................................................................................... 203.2 Pathogen Reduction Requirements ................................................................................. 203.3 Vector Attraction Reduction (VAR) Requirements [503.33] ............................................. 213.4 Applicability of the Requirements [503.15 and 503.25] ................................................... 213.5 Frequency of Monitoring .................................................................................................. 223.6 Sampling Stockpiled or Remixed Biosolids ..................................................................... 223.7 Recordkeeping Requirements [503.17 and 503.27] ......................................................... 233.8 Reporting Requirements for Sewage Sludge [503.18 and 503.28] ................................... 233.9 Permits and Direct Enforceability [503.3] ........................................................................ 25

Chapter 4 Class A Pathogen Requirements .................................................................................. 264.1 Introduction ..................................................................................................................... 264.2 Vector Attraction Reduction to Occur With or After Class A Pathogen

Reduction [503.32(a)(2)] .................................................................................................. 264.3 Monitoring of Fecal Coliform or Salmonella sp. to Detect Growth of Bacterial Pathogens

[503.32(a)(3)-(8)] ............................................................................................................. 274.4 Alternative 1: Thermally Treated Sewage Sludge [503.32(a)(3)] ....................................... 284.5 Alternative 2: Sewage Sludge Treated in a High pH-High Temperature Process (Alkaline

Treatment) [503.32(a)(4)] ................................................................................................. 304.6 Alternative 3: Sewage Sludge Treated in Other Processes [503.32(a)(5)] ....................... 314.7 Alternative 4: Sewage Sludge Treated in Unknown Processes [503.32(a)(6)] ................. 324.8 Alternative 5: Use of PFRP [503.32(a)(7)] ....................................................................... 324.9 Alternative 6: Use of a Process Equivalent to PFRP [503.32(a)(8)] ................................. 334.10 Frequency of Testing .................................................................................................... 33

Chapter 5 Class B Pathogen Requirements and Requirements for Domestic Septage Applied to Agricultural Land, a Forest, or a Reclamation Site ..................................... 36

5.1 Introduction ..................................................................................................................... 365.2 Sewage Sludge Alternative 1: Monitoring of Fecal Coliform [503.32(b)(2)] ....................... 365.3 Sewage Sludge Alternative 2: Use of a Process to Significantly Reduce

Pathogens (PSRPs) [503.32(b)(3)] ............................................................................... 375.4 Sewage Sludge Alternative 3: Use of Processes Equivalent to PSRP [503.32(b)(4)] ....... 38

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5.5 Site Restrictions for Land Application of Biosolids [503.32(b)(5)] .................................... 385.6 Domestic Septage [503.32(c)] ......................................................................................... 41

Chapter 6 Processes to Significantly Reduce Pathogens (PSRPs) .............................................. 436.1 Introduction ..................................................................................................................... 436.2 Aerobic Digestion ........................................................................................................... 43 6.3 Anaerobic Digestion ........................................................................................................ 456.4 Air Drying ........................................................................................................................ 466.5 Composting ..................................................................................................................... 476.6 Lime Stabilization ............................................................................................................ 486.7 Equivalent Processes ...................................................................................................... 50

Chapter 7 Processes to Further Reduce Pathogens (PFRPs) ...................................................... 517.1 Introduction ..................................................................................................................... 517.2 Composting ..................................................................................................................... 517.3 Heat Drying ..................................................................................................................... 537.4 Heat Treatment ............................................................................................................... 547.5 Thermophilic Aerobic Digestion ....................................................................................... 547.6 Beta Ray and Gamma Ray Radiation .............................................................................. 557.7 Pasteurization ................................................................................................................. 557.8 Equivalent Processes ...................................................................................................... 56

Chapter 8 Requirements for Reducing Vector Attraction ............................................................... 588.1 Introduction ..................................................................................................................... 588.2 Option 1: Reduction in Volatile Solids Content [503.33(b)(1)] .......................................... 588.3 Option 2: Additional Digestion of Anaerobically Digested Sewage Sludge [503.33(b)(2)] . 608.4 Option 3: Additional Digestion of Aerobically Digested Sewage Sludge [503.33(b)(3)] .... 608.5 Option 4: Specific Oxygen Uptake Rate (SOUR) for Aerobically Digested Sewage

Sludge [503.33(b)(4)] ....................................................................................................... 608.6 Option 5: Aerobic Processes at Greater than 40ºC [503.33(b)(5)] ................................... 618.7 Option 6: Addition of Alkali [503.33(b)(6)] ........................................................................ 618.8 Option 7: Moisture Reduction of Sewage Sludge Containing No Unstabilized Solids

[503.33(b)(7)] ................................................................................................... 628.9 Option 8: Moisture Reduction of Sewage Sludge Containing Unstabilized

Solids [503.33(b)(8)] ........................................................................................................ 628.10 Option 9: Injection [503.33(b)(9)] .................................................................................... 628.11 Option 10: Incorporation of Sewage Sludge into the Soil [503.33(b)(10)] ........................ 638.12 Option 11: Covering Sewage Sludge [503.33(b)(11)] ....................................................... 638.13 Option 12: Raising the pH of Domestic Sludge [503.33(b)(12)] ...................................... 638.14 Number of Samples and Timing ..................................................................................... 638.15 Vector Attraction Reduction Equivalency ....................................................................... 63

Chapter 9 Sampling Procedures and Analytical Methods .............................................................. 659.1 Introduction ..................................................................................................................... 659.2 Laboratory Selection ....................................................................................................... 659.3 Safety Precautions .......................................................................................................... 659.4 Requirements for Sampling Equipment and Containers ................................................... 669.5 Sampling Frequency and Number of Samples Collected ................................................. 679.6 Sampling Free-Flowing Sewage Sludges ......................................................................... 689.7 Sampling Thick Sewage Sludges .................................................................................... 699.8 Sampling Dry Sewage Sludges ....................................................................................... 699.9 Control of Temperature, pH, and Oxygenation After Sample Collection

Samples for Microbial Tests ............................................................................................ 709.10 Sample Composting and Size Reduction ....................................................................... 719.11 Packaging and Shipment ............................................................................................... 729.12 Documentation ............................................................................................................... 739.13 Analytical Methods ........................................................................................................ 73

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9.14 Quality Assurance ......................................................................................................... 74

Chapter 10 Meeting the Quantitative Requirements of the Regulation ........................................... 7610.1 Introduction .................................................................................................................... 7610.2 Process Conditions ........................................................................................................ 7610.3 Schedule and Duration of Monitoring Events .................................................................. 7710.4 Comparison of Feed Sludge and Sludge Product Samples ............................................ 7910.5 The Effect of Sludge Processing Additives on Monitoring............................................... 7910.6 Collecting Representative Samples ................................................................................ 8010.7 Regulatory Objectives and Number of Samples that Should be Tested .......................... 81

Chapter 11 Role of EPA’s Pathogen Equivalency Committee in Providing Guidance Under Part 503 ...................................................................................................................... 90

11.1 Introduction .................................................................................................................... 9011.2 Overview of the PEC’s Equivalency Recommendation Process ...................................... 9211.3 Basis for PEC Equivalency Recommendations .............................................................. 9211.4 Guidance on Demonstrating Equivalency for PEC Recommendations ............................ 9711.5 Guidance on Application for Equivalency Recommendations ......................................... 9811.6 Pathogen Equivalency Committee Recommendations ................................................. 10011.7 Current Issues .............................................................................................................. 100

Chapter 12 References and Additional Resources ...................................................................... 103

AppendicesA EPA Regional and State Biosolids Coordinators and Listing of EPA Pathogen

Equivalency Members ................................................................................................... 107

I Test Method for Detecting, Enumerating, and Determining the Viability of

B Subpart D of the Part 503 Regulation ............................................................................ 115C Determination of Volatile Solids Reduction by Digestion ............................................... 120

D Guidance on Three Vector Attraction Reduction Tests .................................................. 127E Determination of Residence Time for Anaerobic and Aerobic Digestion ......................... 133

F Sample Preparation for Fecal Coliform Tests and Salmonella sp. Analysis ................... 137

G Kenner and Clark (1974) Analytical Method for Salmonella sp. Bacteria ....................... 141H Method for the Recovery and Assay of Total Culturable Viruses from Sludge ................ 150

Ascaris Ova in Sludge .................................................................................................. 166J The Biosolids Composting Process ............................................................................... 173

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Acknowledgments

This guidance document was produced by the U.S. Environmental Protection Agency (EPA) Pathogen Equivalency Committee (PEC) whose members include Robert Bastian, Bob Brobst, John Cicmanec, G. Shay Fout, Hugh McKinnon, Mark Meckes, Frank Schaefer, Stephen Schaub, and James E. (Jim) Smith, Jr. The contributions of Jim Smith, who was instrumental in the administration, organization, and direction of this project; and of Bob Brobst, Mark Meckes, and Robert Bastian along with Greg B. Kester of the State of Wisconsin, who provided significant comments and guidance, are especially appreciated. Eliot Epstein and Nerissa Wu of E&A Environmental Consultants, Inc. in Canton, Massachusetts, prepared the document with information and comments from the PEC and from EPA and State sludge coordinators and private contribu­tors including Joseph B. Farrell, a consultant, and Robert Reimers of Tulane University. The assistance of reviewers including John Colletti, Madolyn Dominy, Lauren Fondahl, Alia Roufaeal, and John Walker of EPA; Jeffrey G. Faust of Bio Gro; Joe Pearce of the State of North Carolina; Bob Southworth, a consultant; and all other contributors, too numerous to name, is very much appreciated.

The following individuals assisted by updating guidance for analytical procedures: Appendix F: Sample Preparation for Fecal Coliform Tests and Salmonella sp. Analysis - Mark Meckes; Appendix H: Method for the Recovery and Assay of Enteroviruses from Sewage Sludge - Shay Fout; Appendix I: Analytical Method for Viable Helminth Ova - Frank Schaefer; Appendix J: Composting: Basic Concepts Related to Pathogens and Vector Attraction - Eliot Epstein of E&A Environmental Consultants and Bob Brobst of EPA’s Region 8 Office in Denver, CO.

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