I United States Office of .S^/ 7625/4-89/022 Environmental Protection Researcti and Development Atrgus5ust. 1989 7.7. /V Agency Washington, DC 20460 Cj^fLQCfkJ^f^Uf -^ . Pi^ • • - i - oiiOtFt^^rfun' a Kecords Center wEPA Seminar PublicatiOii^s^l^!:­ OTHER: IbStthl Requirements for Hazardous Waste Landfill Design, Construction, and Closure r—i SDMS DocID 463461 Technology Transfer EPA/625/4-89/022 Seminar Publication Requirements for Hazardous Waste Landfill Design, Construction, and Closure August 1989 Center for Environmental Research Information Office of Research and Development U.S. Environmental Protectin Agency Cincinnati, OH 45268 Printed on Recycled Paper NOTICE The information in this document has been funded wholly or in part by the United States Environmental Protection Agency under Contract 68-C8-0011 to Eastern Research Group, Inc. It has been subject to the Agency's peer and administrative review, and it has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. CONTENTS Page Preface vi 1. Overview of Minimum Technology Guidance and Regulations for Hazardous Waste Landfills 1 Background 1 Double Liners and Leachate Collection and Removal Systems 2 Leak Detection Systems 6 Closure and Final Cover 9 Construction Quality Assurance 9 Summary of Minimum Technology Requirements 10 References 10 2. Liner Design: Clay Liners 11 Introduction 11 Materials 11 Clay Liners versus Composite Liners 12 Darcy's Law, Dispersion, and Diffusion 13 Laboratory Tests for Hydraulic Conductivity 17 Field Hydraulic Conductivity Testing 20 Field Tests versus Laboratory Tests 23 Attack by Waste Leachate 24 References 26 3. Flexible Membrane Liners 27 Introduction 27 Composite Liners: Clay versus Synthetic Components 27 Material Considerations 27 Design Elements 30 References 39 4. Elements of Liquid Management at Waste Containment Sites 53 Introduction 53 Overview 53 Primary Leachate Collection and Removal (PLCR) Systems 57 Leak Detection, Collection, and Removal (LDCR) Systems 62 Surface Water Collection and Removal (SWCR) Systems 65 Gas Collector and Removal Systems 66 References 70 5. Securing a Completed Landfill 75 Introduction 75 Flexible Membrane Caps 75 Surface Water Collection and Removal Systems 75 Gas Control Layer 76 Biotic Barriers 78 Vegetative Layer 78 Other Considerations 81 6. Construction, Quality Assurance, and Control: Construction of Clay Liners 89 Introduction 89 Compaction Variables 89 The Construction Process 94 Construction Quality Assurance (CQA) Testing 95 Test Fills 96 7. Construction of Flexible Membrane Liners 99 Introduction 99 Responsibility and Authority 99 CQA Personnel Qualifications 100 Inspection Activities 100 Sampling Strategies 101 Documentation 103 8. Liner Compatibility with Wastes 109 Introduction 109 Exposure Chamber 109 Representative Leachate 110 Compatibility Testing of Components 110 Blanket Approvals Il l Interpreting Data Il l 9. Long-Term Considerations: Problem Areas and Unknowns 113 Introduction 113 Flexible Membrane Liners 113 Clay Liners 118 Leachate Collection and Removal Systems 118 Cap/Closure Systems 119 10. Leak Response Action Plans 121 Background 121 Action Leakage Rate (ALR) 121 Rapid and Large Leakage (RLL) 122 Response Action Plans (RAPs) 124 Preparing and Submitting the RAP 124 Summary 125 List of Abbreviations 127 IV ACKNOWLEDGEMENTS This seminar publication is based wholly on presentations made at the U.S. Environmental Protection Agency (EPA) Technology Transfer seminars on Requirements for Hazardous Waste Landfill Design, Construction, and Closure. These seminars were held from June 20 to September 16, 1988 in San Francisco, California; Seattle, Washington; Dallas, Texas; Chicago, Illinois; Denver, Colorado; Kansas City, Missouri; Philadelphia, Pennsylvania; Atlanta, Georgia; New York, New York; and Boston, Massachusetts. The presenters were: Sarah A. Hokanson, the Earth Technology Corporation, Alexandria, Virginia (Chapters 1 and 10) Dr. David Daniel, University of Texas, Austin, Texas (Chapters 2 and 6) Dr. Gregory N. Richardson, Soil & Materials Engineers, Inc., Raleigh, North Carolina (Chapters 3, 5, arid 7). Dr. Robert M. Koerner, Drexel University, Geosynthetic Research Institute, Philadelphia, Pennsylvania (Chapters 4 and 9). Robert Landreth, U.S. Environmental Protection Agency, Risk Reduction Engineering Laboratory, Cincinnati, Ohio (Chapter 8) Susan Edwards, Linda Saunders, and Heidi Schultz of Eastern Research Group, Inc., Arlington, Massachusetts, prepared the text of this document based on the speakers' transcripts and slides. Orville Macomber (EPA Center for Environmental Research Information, Cincinnati, Ohio) provided substantive guidance and review. PREFACE The U.S. Environmental Protection Agency's (EPA's) minimum technological require­ ments for hazardous waste landfill design were set forth by Congress in the 1984 Hazard­ ous and Solid Waste Amendments (HSWA). HSWA covered requirements for landfill lin­ ers and leachate collection and removal systems, as well as leak detection systems for landfills, surface impoundments, and waste piles. In response to HSWA and other Con­ gressional mandates, EPA has issued proposed regulations and guidance on the design of these systems, and on construction quality assurance, (final cover, and response action plans for responding to landfill leaks. This seminar publication outlines in detail the provisions of the minimum technology guidance and proposed regulations, and offers practical and detailed information on the construction of hazardous waste facilities that comply with these requirements. Chapter One presents a broad overview of the minimum technology guidance and regulations. Chapter Two describes the use of clay liners in hazardous waste landfills, including the selection and testing of materials for the clay component of double liner systems. Chap­ ter Three discusses material and design considerations for flexible membrane liners, and the impact ofthe proposed regulations on these considerations. Chapter Four presents an overview ofthe three parts of a liquid management system, including the leachate collec­ tion and removal system; the secondary leak detection, collection, and removal system; and the surface water collection system. Chapter Five describes the elements of a closure system for a completed landfill, including flexible membrane caps, surface water collec­ tion and removal systems, gas control layers, biotic barriers, and vegetative top covers. Chapters Six and Seven discuss the construction, quality assurance, and control criteria for clay liners and flexible membrane liners, respectively. Chapter Eight discusses the chemical compatibility of geosynthetic and natural liner materials with waste leachates. Chapter Nine presents an overview of long-term considerations regarding hazardous waste landfills, surface impoundments, and waste piles, including flexible membrane and clay liner durability, potential problems in liquid management systems, and aesthet­ ic concerns. Chapter Ten reviews proposed requirements for response action plans for leaks in hazardous waste landfills. This publication is not a design manual nor does it include all of the latest knowledge concerning hazardous waste landfill design and construction; additional sources should be consulted for more detailed information. Some of these useful sources can be located in the reference sections at the end of several chapters. In addition, State and local authori­ ties should be contacted for regulations and good management practices applicable to lo­ cal areas. 1. OVERVIEW OF MINIMUM TECHNOLOGY GUIDANCE AND REGULATIONS FOR HAZARDOUS WASTE LANDFILLS This chapter presents a summary of existing and to maximize leachate collection and removal through proposed regulations and guidance on the design of use ofthe lining system and LCRS. double liners and leachate collection and removal systems, leak detection systems, final cover, and To date, EPA has issued regulations and guidance construction quality assurance. An overview of primarily focusing on double liners and leachate proposed regulations concerning leak response collection and removal systems. Four Federal action plans is given in Chapter Ten. More technical Register notices and guidance documents have been discussion of these and other components of landfill published by EPA in the last 4 years in this area (see design and construction are given in Chapters Two Table 1-1). EPA has issued proposed regulations through Nine. and/or guidance in the additional areas listed in Table 1-2. The draft guidance on the final cover Background issued in July 1982, which was never widely distributed, is being revised for reissuance by the end EPA's minimum technological requirements for of 1989. EPA also plans to issue final regulations for hazardous waste landfill design and construction double liners and for leak detection systems, were introduced by Congress in the 1984 Hazardous including construction quality assurance and and Solid Waste Amendments (HSWA). In HSWA response action plans. Section 3004(o)(l)(A), Congress required all new landfills and surface impoundments to have double liners and leachate collection and removal systems (LCRS). In Section 3004(o)(4), Congress also required Table 1-1. Guidance and Regulations Issued to Date leak detection systems at all new land disposal units, (Double Liners and LCRS) including landfills, surface impoundments, and waste piles. In response