CECW-ET Department of the Army EM 1110-2-501U.S. Army Corps of EngineersEngineer Manual Washington DC 20314-1000 1 February -2-501Design Construction and OperationSMALL WASTEWATER SYSTEMSDistributionRestrictionStatementApproved for public release; distribution is unlimited.
U.S.Army Corps of Engineers DEPARTMENTOFTHEARMY Washington DC 20314-1000
1February 1999
Design Construction and Operation SMALLWASTEWATERSYSTEMS
1. Purpose. This manual is intended to provide guidance and criteria for the design and selection ofdesign such wastewater treatment unit processes and guidance to generally available and accepted refer- small-scale wastewater treatment facilities. It provides both the information necessary to select size andthose with average daily design flows lessthan 379 000 liters per day (IL/d) or 100 000 gallons per day ences for such information. For the purpose of this manual small-scale wastewater treatment systems are(gal/d) including septic tanks for flows less than 18 900 L/d (5000 gal/d) small prefabricated or packageplants for flows between 18 900 L/d (5000 gal/d) and 190 000 L/d (50 000 gal/d) and larger prefabricated treatment systems with capacities of no more than 379 000 L/d (100 000 gal/d).
2. Applicability. This manual applies to all HQUSACE Commands having responsibility for civil worksprojects.
3. Distribution Statement. Approved for public release; distribution is unlimited.
FOR THE COMMANDER:
U.S.Army Corps of Engineers DEPARTMENTOFTHEARMY Washington DC 20314-1000
EM 1110-2-501
No. 1110-2-501 Manual
1 February 1999
Design Construction and Operation SMALLWASTEWATERSYSTEMS
Table of Contents
Paragraph Page
Subject
Purpose Applicability 1-2 1-1 1-1 1-1References .1-3 1-1Distribution Statement Laws and Regulations 1-4 1-5 1-1 1-1
Chapter 2
Preliminary Data Requirements
General 2-1 2-1Recreational Facilities Determination of Effluent Limitations 2-2 2-3 2-1 2-1Site Selection Factors 2-4 2-2
Chapter 3
Wastewater Generation and Characterization
General Visitation and Length of Stay 3-1 3-2 3-1 3-1Variations in Visitation 3-3 3-1Water Usage and Wastewater Generation Monthly and Daily Flow Distribution 3-4 3-5 3-1 3-2Wastewater Characterization 3-6 3-3
Chapter4
Collection Systems
General Absence of Pressurized Water Supply 4-2 4-1 4-1 4-1 qu 4-3 4-1 4-3Gravity Flow Systems Force Main Systems . 4-4 .4-5 4-3Alternative Wastewater Collection Systems 4-6 4-4
pelans
Chapter5
Treatment Design Considerations
General Small Individual Units 5-1 5-2 5-1 5-1Conventional Wastewater Treatment Facilities 5-3 5-4Natural Systems for Wastewater Treatment Stabilization Ponds 5-4 5-5 5-10 5-11Man-Made Wetlands 5-6 5-19Nutrient Removal Sludge Treatment and Disposal 5-7 5-8 5-23 5-25Disinfection of Wastewater Efluents 5-9 5-28
Chapter6
Laboratory Design Sampling andFlow Monitoring
Laboratory Design General 6-1 6-2 6-1 6-1Flow Monitoring Sampling and Analysis 6-3 6-26-4 6-2
Chapter7
Treatment Process Selection
Overview . 7-1 7-1Local Resources Site Visitation 7-2 7-1 7-17-3 7-4 7-1Health Considerations 7-5 -L 7-3Safety Considerations Aesthetic Considerations 7-6 7-7 7-4Access/Security Considerations Comparison of Treatment Processes . . . . 7-8 7-9 7-4 7-5
Chapter8
Design References and ExamplesGeneral 8-1 8-1Military Design Manuals National Small Flows Clearinghouse (NSFC) Publications . .8-2 .8-3 8-1 8-2Wastewater Design Manuals and Texts -8 8-2U.S. Environmental Protection Agency (EPA) Wastewater Design Criteria and Example Matrices . 8-6 8-5 8-2 8-3Additional Design Examples . 8-7 -8
Chapter9
General Wastewater System Design Deficiencies
Overall Considerations General 9-2 9-1 9-1 9-1Conventional Design 9-3 9-5Preliminary Unit Processes . . 9-4 9-6
Primary Treatment Unit Process 9-5 9-10Sludge Dewatering Secondary Treatment Unit Processes 9-6 9-11Non-Conventional Plants 9-7 9-8 9-17 9-17Land Application Sludge Drying and Disposal 6-6 9-19Sewer Collection Systems 9-10 9-11 9-20 9-22Lift Stations 9-12 9-22
Sludge Disposal Chapter10
Definitions General 10-1 10-2 10-1 10-1Toxic Metal Regulations Management Standards 10-3 10-2Effect of Land Application 10-4 10-5 10-2 10-2Pathogen and Vector Attraction Reduction . ... 10-7 10-6 10-2 10-3Land Application Pollutant Limits Exclusions 10-8 10-3Land Application Management Practices . .-.... 10-9 10-3Pathogens and Vector Attraction Reduction Surface Disposal Pollutant Limits 10-10 10-11 10-4 10-4Pathogen Treatment Processes Septage Applied to Agricultural Land Forests or Reclamation Sites 10-12 10-13 10-5 10-6Wastewater Scum 10-14 10-6Composting Methods Composting Additives/Amendments/Bulking Agents 10-15 10-16 10-7 10-7Equipment 10-17 10-7Guidance 10-18 10-10
References Appendix A
Appendix BFacilities
AppendixC Wastewater CharacterizationData
WastewaterDesign Criteria and ExamplesMatrixSummary fromNon-Military Sources Appendix D
Appendix EDesign Examples
