Principles of Design and Operations of Wastewater Treatment Pond Systems for Plant Operators, Engineers, and Managers
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EPA/600/R-11/088 | August 2011 | www.epa.gov /nrmrl PPrinciplesrinciples of Design and Operations ooff Wastewater Treatment Pond Systems fforor Plant Operators, Engineers, and Managers Office of Research and Development National Risk Management Research Laboratory - Land Remediation and Pollution Control Division Principles of Design and Operations of Wastewater Treatment Pond Systems for Plant Operators, Engineers, and Managers Land Remediation and Pollution Control Division National Risk Management Research Laboratory Office of Research and Development U.S. Environmental Protection Agency Cincinnati, Ohio i Notice This document has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. ii 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 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 researches with their clients. Sally Gutierrez, Director National Risk Management Research Laboratory iii Abstract Principles of Design and Operations of Wastewater Treatment Pond Systems for Plant Operators, Engineers, and Managers Wastewater pond systems provide reliable, low cost, and relatively low maintenance treatment for municipal and industrial discharges. However, they do have certain design, operations, and maintenance requirements. While the basic models have not changed in the 30-odd years since EPA published the last ponds manual, there have been some innovations and improved understanding of the complex biological processes at work in these systems. Additionally, new water quality requirements are either in place or about to be put in place throughout the United States, particularly relating to nutrient concentrations, that were not factored into the design specifications when many of the existing ponds were constructed. This updated version of the wastewater treatment ponds manual includes basic design recommendations, discusses the innovations in design that have been made in new, expanded or modified systems, as well as the additional processes that have been added to address nutrient requirements. An emphasis is placed on the importance of operations and maintenance, which is demonstrated in the troubleshooting section and appendices from several states, directed at providing training for operators. iv Contents Notice…………………………………………………………………………………………...…ii Foreword………………………………………………………………………………………….iii Abstract……………………………………………………………………………….….……….iv Contents…………….......................................................................................................................v Figures List……………………………………………………...................................................viii Tables List…………………………………………………………………………………..…...xii Conversion Factors, Physical Properties of Water, and DO Solubility…………………………xiv Glossary.……………………………………………………………………………………… xviii Acknowledgments……………………………………………………………………………...xxii Preface……………….………………………………………………………………………....xxv Chapter 1 Introduction.............................................................................................................1-1 1.1 Background……………………………………………………………………………….1-1 1.2 Pond Nomenclature………………………………………………………………………1-3 1.3 Elements of Pond Processes……………………………………………………………...1-5 Chapter 2 Planning, Feasibility Assessment and Site Selection……………………………2-1 2.1 Introduction………………………………………………………………………………2-1 2.2 Concept Evaluation……………………………………………………………………….2-1 2.3 Resources Required………………………………………………………………………2-1 2.4 Site Identification………………………………………………………………………...2.2 2.5 Site Evaluation……………………………………………………………………………2-3 2.6 Site and Process Selection……………………………………………………………......2-5 2.7 Design Criteria of Municipal Wastewater Treatment Ponds…………………………….2-6 2.8 State Design Standards…………………………………………………………………..2-6 Chapter 3 Design of Municipal Wastewater Treatment Ponds……………………………....3-1 3.1 Introduction……………………………………………………………………………...3-1 3.2 Anaerobic Ponds………………………………………………………………………….3-1 3.3 Facultative Ponds…………………………………………………………………………3-7 3.4 Aerated Pond Systems…………………………………………………………………..3-11 Chapter 4 Physical Design and Construction……………………………………..….………4-1 4.1 Introduction………………………………………………………………………………4-1 4.2 Dike Construction………………………………………………………………………...4-1 4.3 Pond Sealing……………………………………………………………………………...4-3 4.4 Pond Hydraulics…………………………………………………………………...........4-14 4.5 Pond Recirculation and Configuration………………………………………………….4-16 Chapter 5 Advances in Pond Design…………………………………………………………5-1 5.1 Introduction………………………………………………………………………………5-1 5.2 Advanced Integrated Wastewater Pond Systems® (AIWPS®)………………………….5-1 5.3 Systems with Deep Sludge Cells….………………………………………………..........5-20 5.4 High-Performance Aerated Pond System (RICH DESIGN)…………………………...5-33 v 5.5 Biolac Process (Activated Sludge in Earthen Ponds)…………………………………...5-39 5.6 Lemna Systems………………………………………………………………………….5-53 5.7 LAS International, Ltd., Accel-o-Fac® and Aero-Fac® Systems....……………………..5-64 5.8 Oxygen Addition Systems………………………………………………………………5-65 Chapter 6 Nutrient Removal…………………………………………………………….…..6-1 6.1 Introduction……………………………………………………………………………..6-1 6.2 Facultative Ponds……………………………………………………………………….6-1 6.3 Aerobic Ponds…………………………………………………………………………..6-9 6.4 Commercial Products…………………………………………………………………...6-19 6.5 Removal of Phosphorus…………………………………………………………………6-27 Chapter 7 Upgrading Pond Effluents………………………………………………….……7-1 7.1 Introduction………………………………………………………………………….…..7-1 7.2 Solids Removal Methods…………………………………………………………….…..7-1 7.3 Operations Modifications and Additions……………………………………………….7-28 7.4 Control of Algae and Design of Settling Basins………………………………………...7-30 7.5 Comparison of Various Design Procedures…………………………………………......7-34 7.6 Operational Modifications to Facultative Ponds……………………………………......7-34 7.7 Combined Systems………………………………………………………..…………….7-37 7.8 Performance Comparisons with Other Removal Methods……………………………...7-37 Chapter 8 Cost and Energy Requirements……………………………………………………8-1 8.1 Introduction……………………………………………………………………………...8-1 8.2 Capital Cost……………………………………………………………………………...8-1 8.3 Updating Costs…………………………………………………………………………..8-4 8.4 Cost Data for Upgrading Methods………………………………………………………8-4 8.5 Energy Requirements……………………………………………………………………8-11 Chapter 9 Operation and Maintenance……………………………………………………….9-1 9.1 Introduction.……………………………………………………………………………..9-1 9.2 Terminology.……………………………………………………………………………..9-1 9.3 Control Testing Information…………………………………………………………….9-2 9.4 Operation and Maintenance for Ponds………………………………………………….9-11 9.5 Safety around Ponds…………………………………………………………………….9-20 9.6 Troubleshooting…………………………………………………………………………9-22 Appendices A State Design Criteria for Wastewater Ponds………………………………………………A-1 B Summary of Pond Characteristics………………………………………………...………..B-1 C Design Examples…………………………………………………………………………...C-1 D Case Studies……………………………………………………………………………......D-1 vi E Troubleshooting……………………………………………………………………………..E-1 F Study Guides for Pond Operators…………………………………………………………...F-1 F-1 Introduction…………………………………………………………………………....F-2 F-2 Advanced……………………………………………………………………………...F-29 G Discharge Guidance………………………………………………………………………..G-1 H Guidance for Deploying Barley Straw……………………………………………………..H-1 References…………………………………………………………………………………..…R-1 vii Figures Number Page 1-1 The Nitrogen Cycle in Wastewater Pond System 1-9 1-2 Relationship between pH and Alkalinity 1-11 1-3 Changes Occurring in Forms of Nitrogen Present in a Pond Environment under 1-14 Aerobic Conditions 3-1 Method of Creating a Digestion Chamber in the Bottom of an Anaerobic Pond 3-7 3-2A Static Tube, Brush and Aspirating