MANUAL FOR SEPTIC SYSTEM
PROFESSIONALS IN MINNESOTA
DETAILED DIRECTORY
INTRODUCTION ...1-1
How to Use This Manual ...1-1
Understanding Septic Systems ... 1-1
Why Are Septic Systems Necessary? ...1-1
What Do Septic Systems Do? ...1-2 How Does a Septic System Work? ...1-2
Plumbing...1-3 Septic tank ...1-3 Soil treatment area ...1-4 Enhancements ...1-5
How Is The Sewage Treated? ...1-6 Why Do Septic Systems Fail? ...1-7
Improper maintenance ...1-7 Overuse of water ...1-7 Improper design or installation ...1-7
Cleaning up a Sewage Back-up ...1-8
Clean up tips: ...1-8 Compliance Inspections ...1-8 Abandonment ...1-8
Operation and maintenance tips ...1-9
Control water use ...1-9 Eliminate harmful products from the system ...1-9 Do not use additives ...1-9 Regularly clean/pump and inspect the septic tank ...1-9 Maintain pumps and filters properly ...1-9 Protect the soil treatment area ...1-10
Odor Issues and Onsite Sewage Treatment Systems ...1-11
1. Odors in the home ...1-11 2. Odors near the septic tank ...1-12 3. Odors near a pretreatment unit ...1-12 4. Odors near the soil treatment area ...1-12 5. Odors in the yard ...1-12 Designer Responsibilities: Providing Information to the Homeowner ...1-13 I. Pre-Design Communication ...1-13 A. Pre-design meeting with system owner ...1-13 II. Post-Design Communication ...1-14 A. Final design review ...1-14 B. Management Plan ...1-14 Installer Responsibilities: Providing Information to the Homeowner ...1-15 I. Pre-Installation Tasks ...1-15 A. Agree on establishing the vegetative cover and topsoil. ...1-15 B. Septic System Management Plan (select one box) ...1-15 II. Post-Installation Tasks ...1-16 A. Discuss ponding, run-off, and surfacing. ...1-16 B. Explain and show the system to the homeowner. ...1-16 C. Discuss household water and product use tips with the homeowner. ...1-18 Maintainer & Service Provider Responsibilities: Providing Information to the Homeowner ...1-19 A. Septic system Management Plan ...1-19 B. During service call, accomplish these tasks and discuss these topics with a homeowner. 1-20 C. Communication with the homeowner. ...1-21 D. Discuss household water and product use tips with the homeowner. ...1-22 Household Product and Water Use Guidelines for Homeowners ...1-22 More Information About Septic Systems ...1-23
Local and Regional ...1-23 State and National ...1-23 Publications and DVDs ...1-24
University of Minnesota Bookstore
bookstores..umn.edu ...1-24
For More Information ...1-24
References ...1-24
ADMINISTRATION ...2-1
Overview ...2-1 Management Guidelines ...2-1 Class V Systems ...2-2 Land Application Requirements ...2-2
State Agencies ... 2-3
Overview ...2-3
Minnesota Pollution Control Agency ...2-3
Overview of Minnesota’s SSTS Rules ...2-5 System Classifications ...2-5 Type I systems ...2-6 Type II systems...2-7 Type III systems ...2-7 Type IV systems ...2-8 Type V systems ...2-10 Product development permits ...2-10 Compliance Criteria ...2-10 Imminent Threat to Public Health or Safety (ITPHS) ...2-12 Failing to protect groundwater ...2-13 Cesspool, seepage pit, leaching pit, drywell ...2-13 Limiting layer ...2-15 Systems Not Operated or Maintained Properly ...2-17 Systems with flows greater than 2,500 gpd ...2-17 Compliance criteria for systems with partial component replacement ...2-17 Non-Code System ...2-17 Inspection Process ...2-18 Disclosure vs. Inspection ...2-19 7083 Certification and Licensing Requirements ...2-20 Certification ...2-20 Licensing Exemptions ...2-20 Types of certification and corresponding responsibilities ...2-21
Maintainner ...2-23 Service Provider ...2-23 Installer ...2-23 Inspector ...2-24 Training ...2-25 Continuing education ...2-25
Exam ...2-25 Experience ...2-25 Designer Experience – ...2-26 Installer Experience – ...2-26 Inspector Experience - ...2-26 Maintainer Experience - ...2-26
Other Minnesota Regulatory Bodies ... 2-26
Board of Architecture, Engineering, Land Surveying, Landscape Architecture, Geoscience and Interior Design ...2-26 Board of Water and Soil Resources ...2-27 Department of Health ...2-27Existing Conditions – Wells and SSTS ...2-27 Isolation Distances ...2-27 Sewers ...2-28 Sumps, Lift Stations, Grinder Pumps ...2-28 Setbacks to Sensitive Wells ...2-28 Water Supply Pipes ...2-30 Abandoned Wells and Abandoned SSTSs ...2-30 System Compliance ...2-30 Before July 1, 1974 ...2-30 July 1, 1974 to June 31, 1989 ...2-30 July 1, 1989 to present ...2-31 Environmental Wells ...2-31 Variances from the Well Code ...2-31 Source Water Protection ...2-32 Wellhead Protection ...2-32 Source Water Assessments ...2-35
Department of Labor and Industry ...2-35
Plumbing Code ...2-35 Occupational Safety and Health ...2-37 Boilers Operator License ...2-38
Department of Natural Resources ...2-38 Department of Transportation ...2-40
Local Ordinances ... 2-40
System Performance vs. Program Performance ...2-41 Local Ordinance Requirements for Performance Programs ...2-42 Management ...2-42
Type I-III Systems ...2-43 Type IV-V Systems ...2-43 References ...2-44
SEWAGE TREATMENT UTILIZING SOIL ... 3-1
Impacts of Effluent on Groundwater...3-2 Soil Treatment Processes ...3-2
Biomat ...3-3 Soil Treatment ...3-4 Pathogen Removal ...3-4 Nutrient Removal ...3-5 Nitrogen ...3-5 Phosphorus ...3-6 Residence Times ...3-6
Soil Science Basics ... 3-7
Soil Defined ...3-7
What is Soil? ...3-7 Components of Soil ...3-7
Soil Texture ...3-7 Described ...3-7 Soil Textural Classification ...3-8 The twelve soil textural classes ...3-9 Field Determination of Soil Texture ...3-10 Procedure ...3-11 Soil Structure ...3-13
Soil Structure in Minnesota ...3-13 Soil Structure Description...3-13
Shape ...3-14 Size ...3-15 Grade ...3-15 Consistence ...3-17 Soil Colors ...3-17 Significance of Color ...3-17 Determining Soil Colors ...3-18
Conditions for Measuring Color ...3-19 Reading the Color ...3-20
Redoximorphic Features ...3-23
Redoximorphic Feature Formation ...3-23 Redoximorphic Feature Description ...3-24
Other Soil Features ...3-24
Nodules and Concretions ...3-24 Soft accumulations ...3-24 Soft rock fragments ...3-24 Surface features ...3-24 Roots and root traces ...3-24 Soil Profile ...3-24 Soil Horizons ...3-25 Determining Boundaries ...3-26 Soil Morphology ...3-26 Soil Pores ...3-26 Soil Permeability ...3-26 Saturated Hydraulic Conductivity ...3-26 Infiltration ...3-27 Plastic Limit ...3-28
Procedure for Determining Plastic Limit in the Field ...3-28
Porosity ...3-29 Bulk Density ...3-29 Percolation Rate ...3-29 Soil Formation ...3-29 Parent Materials ...3-30 Lacustrine ...3-30 Alluvium ...3-30 Colluvium ...3-31 Glacial Outwash ...3-31 Glacial Till ...3-31 Loess ...3-31 Organic Soils ...3-32 Bedrock ...3-32 Types ...3-32 Issues ...3-32 Karst ...3-33 Preferential flow ...3-33
Soft bedrock ...3-33 Restrictive ...3-33
Climate ...3-34
Precipitation ...3-34 Temperature ...3-34
Time of Soil Formation ...3-34 Vegetation and Organisms ...3-35
Plants ...3-35 Microorganisms and Soil-Dwelling Animals ...3-35
Topography ...3-35
Minnesota Soils ...3-35 References ...3-37
SITE EVALUATION ... 4-1
Overview of Site Evaluation Process ... 4-1
Purpose ...4-1 Overview of requirements ...4-1
Preliminary Evaluation ... 4-2
Gathering Information ...4-2 Soil Survey Reports and Geologic Atlases ...4-2
Soil Survey Vernacular ...4-2 Soil Survey In Preliminary Site Evaluation ...4-3
Hard Copy Soil Surveys ...4-3 Online Soil Surveys ...4-4 Detailed Soil Survey Maps ...4-5 Online availability ...4-6 Saturated Hydraulic Conductivity ...4-6 Linear Extensibility ...4-6 Water Features ...4-6 Soil Treatment Areas - Trench, At-Grade, Mound ...4-7 Drainage Classification ...4-7 Slope Phases ...4-7 Reading the Soil Survey ...4-7 Map unit inclusions ...4-8
Soil Series Limitations ...4-9
Sand and Rock Fragment Treatment Concerns ...4-9 High clay content soils: acceptance and smearing concerns ...4-9
Plastic limit ...4-9 Above ground system required ...4-10
Slopes ...4-10 Water table depths ...4-10 Permeability ...4-10
Property Limitations ...4-10
Determining Homeowner Preferences ...4-10 Setbacks ...4-11
Unknown Buried Items ...4-13
Property lines ...4-13
Lot line verification (survey) ...4-13
Easements ...4-13
Road right-of-ways ...4-13 Utility easement ...4-13
Dwellings ...4-13 Lakes, rivers, streams ...4-13 Wells ...4-14 Ownership ...4-14
Legal Land Survey Description ...4-14
Zoning ...4-15
Field Evaluation ... 4-16
Landscape Position ...4-18
Landscape/Topography ...4-18 Landform ...4-18 Hillslope Position and Slope Shape ...4-18
Slope ...4-19
Slope determination ...4-19 Upslope conditions–run-on/diversions ...4-20 Slopes, elevations, and benchmarks ...4-20
System orientation to slope ...4-20 Benchmark ...4-20 Contours ...4-20 Flooding ...4-20
Distance from floodplain ...4-21 Floodway, flood fringe, and floodplain identification ...4-21
Soil Observations ...4-22
Soil Observations Procedure ...4-23 Soil Observation Log ...4-24
Limiting layer identification ...4-25
Redoximorphic features ...4-25
Formation ...4-25 Identification ...4-25 Limitations ...4-25 Recognition of problem soils ...4-26 Red parent material ...4-26 Thick topsoil ...4-26 Elluvial horizons ...4-27 Lamellae ...4-27 What do lamellae indicate? ...4-27 Is there a thickness criteria where lamellae become limiting? ...4-27 Calcareous ...4-28 Highly decomposed bedrock ...4-28
Saturated soils ...4-28
Water Tables ...4-28 Soil color determination ...4-29 Soil color implications ...4-29
Bedrock ...4-29 Restricting soil conditions ...4-30
Flood Elevation ...4-30 Disturbed Areas ...4-30 Fill Soils ...4-30 Cut Areas ...4-31
Soils, Impacts on ISTS Design ... 4-32
Soil Texture ...4-32
Constructability ...4-32
Smearing ...4-32 Compaction ...4-32 Soil structure - Preferential movement ...4-32 Soil water movement ...4-33
Unsaturated water movement ...4-33 Saturated hydraulic conductivity ...4-33
Determination of percolation rates of most restrictive horizon ...4-35 The Percometer and the Hook Gauge ...4-35 Percolation Test Data Sheet ...4-36 Steps in a Percolation Test ...4-36 Use soil observations to locate suitable area ...4-36 Locate an adequate number of test holes...4-36 Dig the Test Holes ...4-36 Prepare the Test Holes ...4-37 Distinguish Between Saturation and Soil Swelling ...4-38 Measure the Percolation Rate ...4-38 Calculate the Percolation Rate ...4-39
Groundwater mounding ...4-39
Soil Loading Rate ...4-39
Soil texture ...4-40 Soil structure ...4-40 Soil consistence ...4-40 Percolation rate ...4-40 Basic predictive assessment methods ...4-40
Assumptions ...4-40 Parameters ...4-40 Application ...4-40 Advanced assessment methods ...4-41
Hydraulic Linear Loading Rate ...4-41
Proper protection of tested area ...4-41
Staking the Site ...4-41
Special equipment needed ...4-41 Equipment limitations ...4-41 Traffic patterns to minimize compaction ...4-41 Maximum lift/of typical pump trucks ...4-42 Winter operation and protection from freezing ...4-42
Site Evaluation Reporting Requirements ... 4-42
Soil and Site Additional Reporting [Over 2,500 gpd] ...4-43
Mounding evaluation ...4-44
Method ...4-44 Results ...4-44
Problem soils assessment ...4-44 Topographic and site variability evaluation ...4-44 Soil property variation and interpretation ...4-45 Water table monitoring basics ...4-45
Equipment ...4-45 Duration ...4-45 Proper location ...4-45
Problem Sites and Soils ... 4-46
Type I, II, III, IV, and V Systems ... 4-46
Rapidly Permeable Soils ...4-46
Sands and Gravels ...4-46 Loamy, Medium, and Fine Sands ...4-46
Small Lots ...4-47
General Description ...4-47 Solutions ...4-47
Reduce water consumption or reuse ...4-47 Small field with holding tank ...4-47 Pretreatment to reduced size drainfield ...4-47 Time dosing from large pump tank ...4-47 Box mound/vertical side wall mound ...4-47 Lack of Unsaturated Soil ...4-47
Pretreatment technologies ...4-48 Reduced hydraulic linear loading rate ...4-48 Texture break ...4-48 Designed perimeter drain tile/curtain drain...4-48 Reduce water consumption or reuse ...4-48
Disturbed Soil ...4-49
Soil modification methods ...4-49
Options ...4-49 Excavate out the disturbed soil ...4-49 Use of the disturbed soil ...4-49 Manipulate the disturbed soil ...4-50 Limitations ...4-50 Effects ...4-50
Design pressure distribution with varying elevation ...4-50
Varying perforation sizes and spacing with valving and management ...4-50 Flooding ...4-50 Slowly Permeable Soils ...4-51
60 to 120+ mpi ...4-51
Soil Descriptions ... 4-51
Texture ...4-52 Structure ...4-52 Color ...4-52 Landscape ...4-52 References ...4-52Appendix 1 - Minnesota Wetland Conservation Act Contractor Responsibility
and Landowner Statement Form ... 4-53
WASTEWATER SOURCES AND FLOWS ... 5-1
Wastewater Sources ...5-1
Sewage ...5-1
Definition ...5-1 Non sewage sources ...5-2 Clear water additions ...5-2 Water softeners...5-3 Iron filters ...5-3 How do iron filters work? ...5-3 Can a water softener be used to remove iron? ...5-4 Challenges ...5-4 Options ...5-4 Reverse Osmosis ...5-5 High-efficiency furnaces ...5-5 Industrial wastewater ...5-6 Garage floor drains ...5-6
Other Establishments ...5-7
Code Requirements ...5-8 Related Licensing Requirements ...5-8 Apartment buildings ...5-9 Day cares ...5-9 Commercial kitchen ...5-10 Campgrounds ...5-11 Privies ...5-11
RV Dump Stations ...5-11 Laundromats ...5-12 Office Buildings ...5-12 Schools and Churches ...5-12 Hotels and Motels ...5-12 Medical Facilities ...5-12 Beauty Salons and Barbers ...5-12 Automotive Garages ...5-13 Filling Stations, Service Stations, Car Washes ...5-13 Flow Determinations for Clusters & Other Establishments ...5-14
Hydraulics – Flow Rates ... 5-16
7080 Versus 7081 ...5-16 General Hydraulic Considerations ...5-16 Design Process for Flow Equalization...5-17 Estimates of Flow for Dwelling Design ...5-18 Current Use ...5-20 Architectural Issues ...5-20 LGU ordinance considerations ...5-21 Financial considerations ...5-21 Sample bedroom determinations ...5-21 Estimated Flow- Class II – IV Dwellings ...5-21 Class II ...5-22 Class III ...5-22 Class IV ...5-22 Measuring Flow for Design and Management ...5-22
Water Meters ...5-22
Installation ...5-23
Event counter (cycle counter) ...5-23 Elapsed time meter ...5-24 Other Establishments and MSTS Hydraulic Determinations ...5-25
1. Dwellings ...5-25 Per capita applicability ...5-25 2. Other Establishments ...5-26 Measured Flow ...5-29 Design Process for Determining Flow ...5-30 Design best-practices checklist ...5-30
3. Infiltration from the Collection System ...5-31
Waste Characteristics: Waste Strength Components ... 5-31
Components of Wastewater ...5-31 Waste Strength ...5-32Biochemical Oxygen Demands (BOD5), Dissolved Oxygen, and Total Suspended Solids (TSS) ...5-32
Types of BOD ...5-34
Biochemical Oxygen Demand ...5-34 Biochemical Oxygen Demand (BOD5) ...5-34 Carbonaceous Biochemical Oxygen Demand (CBOD) ...5-34 Nitrogenous Biochemical Oxygen Demand (NBOD) ...5-34 Ultimate Biochemical Oxygen Demand (UBOD) ...5-34
Source and Impact of BOD5 on Systems ...5-35
Chemical Oxygen Demand (COD)...5-35
Total Suspended Solids (TSS) ...5-36
Impact of TSS on systems ...5-36
Fats, Oils and Grease (FOG) ...5-37
Sources of FOG ...5-37 Impact of FOG on systems ...5-38 Fat ...5-38 Oils ...5-38 Grease ...5-39 Design Process for HSW...5-39
Biological Treatment Processes ... 5-39
Wastewater Oxygen States ...5-39Dissolved Oxygen (DO) ...5-40 pH ...5-42 Temperature ...5-42 Alkalinity ...5-43
Pathogens ...5-43
Fecal Coliform (FC) ...5-44 Category A Products and Treatment Levels ...5-45 Category B Products and Treatment Levels ...5-45 Nutrient Listing ...5-46
Nutrients ... 5-46
MN Rule Treatment Requirements for Nutrients ...5-46
The Nitrogen Cycle in Soil-Groundwater Systems ...5-48 1. Nitrogen Fixation ...5-48 2. Ammonification ...5-48 3. Synthesis ...5-48 4. Nitrification ...5-49 5. Denitrification ...5-49 Health Effects from Groundwater Contamination with Nitrates ...5-50 Methemoglobinemia ...5-50 Carcinogenesis ...5-50 Birth Defects ...5-50 Surface Water Pollution with Nitrogen ...5-50 Eutrophication ...5-50 Oxygen Demand through Nitrification ...5-50 Ammonia Toxicity to Aquatic Organisms ...5-51 Biological Nitrification ...5-51 Process Microbiology ...5-51 Dissolved Oxygen Requirements and Organic Loading Rates ...5-52 Suspended Growth Systems ...5-52 Attached-Growth Systems ...5-52 pH and Alkalinity Effects on Nitrification ...5-53 Temperature Effects ...5-53 Effect of Inhibitors ...5-53 Example: Calculation of alkalinity and oxygen requirements for nitrification ...5-54 Summary of Nitrification Processes ...5-55 Biological Dentrification ...5-55 Heterotrophic Dentrification ...5-55 Wastewater as Carbon Source...5-55 Heterotrophic ...5-56 Example: Calculation of stoichiometric equations for nitrate ...5-54 Example: Recalculation of stoichiometric equations for nitrate reduction using the
wastewater as the carbon source ...5-55 External Carbon Source ...5-56 Example: Design of dentrification system using methanol as the carbon source ...5-57 Example: Design of dentrification system using acetic acid as the carbon source ...5-59
Phosphorus ...5-61 Other Components of Wastewater ...5-62
Chemicals and hazardous waste ...5-62
Monitoring Wastewater Characteristics ... 5-62
Certified Labs ...5-63 Sampling ...5-63References ...5-64
Appendix 1 ... 5-68
Biological Hazards in Wastewater: FAQs for Septic System Professionals ...5-68
PLUMBING AND COLLECTION ... 6-1
Introduction ... 6-1
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... 6-1
Plumbing ...6-1
Basement sump, grinder and effluent pumps ...6-1
Non-flush toilets ...6-2
Flammable waste and sediment traps ...6-3
Maintenance ...6-3 Sediment Traps ...6-3 Flammable waste interceptor ...6-5 Maintenance ...6-5 Bottom Sand/Sediment Layer Management ...6-5
Collection ... 6-6
Building sewer ...6-6Definition, description, rule requirement ...6-6 Building sewers ...6-7
Pipe material ...6-7
Design...6-7 Pumps in the basement ...6-7 Separation technology ...6-7 Clay and Orangeburg Pipe ...6-8 Ductile Iron ...6-8 High Density Polyethylene ...6-8 Acrylonitrile Butadiene Styrene ...6-9 Polyvinyl Chloride ...6-9 PVC Standard Dimensions and Materials ...6-9 Nominal Diameters ...6-9 Iron Pipe Standard - IPS ...6-10 Material Codes ...6-10
ASTM International ...6-10 ASTM D1785 - Schedule 40, 80, and 120 ...6-10 ASTM D2241 - Pressure Rated, Standard Dimension Ratio PVC Pipe ...6-10 SDR and Schedule Comparison ...6-11 Additional Plastic Pipe Standards ...6-11 PW and DWV ...6-11 Storage and Handling ...6-12 Pipe Marking and Identification ...6-12 Pipe Colors ...6-12 Fittings and Joints ...6-12 Fittings ...6-13 Slope/Grade ...6-14 Cleanouts ...6-14
Setbacks ... 6-15
Collection Design ...6-16 Installation ...6-17 Beginning excavation ...6-17 Pipe Cutting ...6-18Excavation and Backfilling ...6-18
Embedment ...6-19
Embedment Methods ...6-19 Finishing ...6-21
Connecting Pipe and Fittings...6-21
Solvent-Welding ...6-21 Threaded Connections ...6-23 Mechanical Joints ...6-23 Gaskets ...6-23 Thrust Blocks ...6-24 O&M and Troubleshooting ...6-24 Plugging ...6-25 Freezing ...6-25
SEPTIC TANKS ... 7-1
Definition and Description ...7-1
Physical processes ...7-1 Biological and chemical processes ...7-2
Factors affecting septic tank performance ...7-2 Setbacks ...7-3 Design Impacts and Options ...7-3
Tank Sizing for Dwellings ...7-4
Garbage Disposal and Pumps in Basements ...7-4 Determining Tank Capacities ...7-5 Multiple Tanks ...7-6 Compartmentalization of Single Tanks ...7-7 Septic tank sizing for MSTS and other establishments ...7-8
Lint filters, effluent screens, and pressure filters ...7-9
Tank geometry ...7-9 Special considerations in septic tank design ...7-9
External grease interceptors ...7-9 Restaurants ...7-10 Laundromats ...7-10 Slaughterhouses ...7-11 Dairies, milkhouses...7-11
Tank Location and Bury Depth ...7-11 Insulating Tanks ...7-12 Vehicular Traffic ...7-13 Septic tank alarms ...7-13 Tees and baffles ...7-13
Access risers and inspection ports ...7-16
Septic Tank Effluent Screens ...7-17
Tank Construction ... 7-19
Overview ...7-19 Sewage tank registration ...7-19 Materials ...7-20 Structural soundness ...7-20
Tank storage, transport, and use ...7-20 Precast concrete septic tanks and sealing materials ...7-21
Pipe penetrations for precast concrete tanks ...7-22
Rotationally molded polyethylene/polypropylene septic tanks ...7-22 Fiberglass reinforced plastic septic tanks ...7-23 Constructing pour-in-place tanks ...7-24
Watertightness testing ...7-25 Hydrostatic testing ...7-26
Hydrostatic testing procedure for tanks: ...7-27
Vacuum testing ...7-27 Visually examining existing tanks ...7-28 Tank labeling ...7-29
Tank installation ...7-29
Safety ...7-29
Planning and excavation ...7-29
Setting and securing a tank ...7-30 Installation in high water table conditions ...7-30 Dimension/capacity check and the use of existing tanks ...7-32
Placing and bedding tanks ...7-32
Insulating tanks ...7-33 Pipe penetrations ...7-33 Baffling ...7-34 Sealing between joints, inlet and outlet pipes ...7-35 Access risers and inspection pipes ...7-35
Cleaning accesses ...7-36
Tank Venting ...7-36 Backfilling tanks ...7-37 Supply pipe ...7-37 Final grading ...7-37
Operation and Maintenance ...7-37 Tank cleaning ...7-38
Effluent screens ...7-40
Myths and additives ...7-40 Tank inspections and troubleshooting ...7-40 Odor ...7-41 Evaluating sewage tank performance ...7-42 Flow, settling and bacterial action ...7-42 Effluent quality ...7-44 Watertightness ...7-44 Baffles ...7-45 Supply lines ...7-46
Management of supply lines ...7-47
Tank abandonment ...7-48
Holding Tanks, Privies and Graywater Systems ... 7-49
Holding Tanks ...7-49
Definition ...7-50 Rule Requirements ...7-51 Setbacks and location ...7-51 Application and Design ...7-52 Capacity ...7-52
Floodplain areas ...7-52
Reduced-size systems ...7-52
Holding Tank with Drainfield: An Alternative ...7-54
Installation ...7-54 Operation, Maintenance and Troubleshooting ...7-54 Inspection and Abandonment ...7-54
Privies ...7-54
Definition ...7-54 Rule Requirements ...7-55 Design and Setbacks ...7-55
Ventilation ...7-55 Operation and Maintenance ...7-56 Odor Control ...7-56 Keeping wood odor-free ...7-56
Troubleshooting ...7-57
Odors ...7-57
Inspection ...7-57 Abandonment ...7-57
Graywater Systems ...7-57
Definition and Applications ...7-57 Rule Requirements ...7-58 Segregation of wastewater flows ...7-59 Non-flush toilets ...7-61
Incinerating toilet ...7-61 Composting toilet ...7-61 Chemical toilet ...7-62 References ...7-62
TANK MANAGEMENT AND SEPTAGE ... 8-1
Tank Maintenance ...8-1
Cleaning ...8-1
Scum and Sludge Accumulations ...8-1 Septic Tank Cleaning Procedure ...8-2
How to Clean a Tank...8-2
1. Locate Maintenance Hole ...8-2 2. Open Maintenance Hole ...8-2 3. Inspect Contents ...8-3 4. Remove All Tank Contents ...8-3 Cleaning Procedure ...8-3 Mechanical Mixing ...8-4 Back Flush ...8-4 5. Inspect Tank ...8-4 Baffles ...8-4 Water tightness...8-5 Inflow from System ...8-5 6. Replace Maintenance Hole Cover ...8-5 7. Restore Yard ...8-5 8. Get Paid ...8-5 9. Proper Land Application of the Septage ...8-6 10. Receipt ...8-6 11. Improper Maintenance Notice...8-6
Effluent screens ...8-6 Cleaning an effluent screen ...8-7 Troubleshooting an Effluent Screen ...8-8
Problems: Professional Cleaning, Not Additives ...8-8
Effect of Using Hydrogen Peroxide ...8-9
Safety Keys for Maintainers ...8-10 Safety gear for Maintainers ...8-10
Safety for Confined Spaces ...8-10
Hydrogen Sulfide (H2S) ...8-11 Carbon Dioxide (CO2) ...8-11
Gasoline Fumes ...8-11
Electricity Hazards ...8-11
Infectious Disease Hazards ...8-12 Structural Collapse Hazards ...8-12 Septage Management...8-12
Definitions ...8-13
Septage Treatment ...8-16
Septage and Its Characteristics ...8-16 Variability of Septage ...8-20 Restaurant Grease Trap Wastes ...8-20
Potential Complications ...8-21 Transferring Septage and Restaurant Grease Trap Waste to a Publicly Owned Treatment Works (POTW) ...8-22
Septage Storage Requirements ...8-23 Land Application Requirements for Septage ...8-23
Requirements for Pathogen Control and Vector Attraction Reduction ...8-23
Pathogen Control Requirements ...8-23
Pathogen Reduction Alternative #1
for Domestic Septage with pH Treatment Applied to Non-Public Contact Sites ...8-25 Crop Restrictions ...8-25 Grazing Restrictions ...8-25 Site Restrictions...8-25 Pathogen Reduction Alternative #2
for Domestic Septage without Additional Treatment Applied to Non-Public Contact Sites ...8-26 Crop Restrictions ...8-26 Grazing Restrictions ...8-26 Site Restrictions...8-26
Vector Attraction Reduction Requirements ...8-26 Lime Stabilization Treatment ...8-27
Vector Attraction Reduction Alternatives for Domestic Septage Applied to Non-Public Contact Land ...8-27 Alternative 1: Injection ...8-27 Alternative 2: Incorporation ...8-27 Alternative 3: pH Adjustment ...8-27 Site Suitability Requirements for Septage Application ...8-30
Soil Terminology: Definitions for Septage Application ...8-30
Site Selection ...8-31 Using the Soil Survey ...8-32
Soil Survey Tables: Useful Information for Determining Suitability of Soils for Septage
General Site Management ...8-34
Allowable Application Rates ...8-34 Land Spreading ...8-35 Septage Application Rate Limits ...8-35
Additional Nitrogen Management Requirements ...8-36 EXAMPLE 1: MANA rate determined using option 1 ...8-36 EXAMPLE 2: MANA rate determined using option 1 ...8-37 EXAMPLE 3: MANA rate determined using option 2 ...8-37 EXAMPLE 4: MANA rate determined using option 2 ...8-37
Truck Calibration ...8-37
EXAMPLE CALIBRATION: ...8-37 Specific Nitrogen Management Requirements: ...8-38 Hydraulic Loading Rate Limits ...8-39 Maintainer Qualifications ...8-39 Record Keeping ...8-39 Requirements for Land Application of Restaurant Grease Trap Waste ...8-41 References ...8-42 Minnesota Pollution Control Agency Offices ...8-42
PUMPING SYSTEMS ... 9-1
Overview ... 9-1
Pumping Applications ... 9-1
Pumping in Gravity Systems ...9-1 Pumping in Pressure Systems ...9-3
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... 9-4
Sump Basket ...9-4 Specifications ...9-5 Construction ...9-5 Discharge line ...9-5 Sumps for buildings ...9-5 Covers ...9-5 Single family dwellings ...9-5 Sump vent ...9-5 Clear water sumps ...9-6 Pump Tank...9-6 Definition ...9-6 Requirements ...9-7
Dosing Regimens: Demand vs. Timed ...9-8 Demand Dosing ...9-8 Timed Dosing ...9-9 Flow Equalization ...9-10 Pumps ...9-11 Rule Requirements ...9-11
Pumps for Gravity Distribution ...9-11 Pumps for Pressure Distribution ...9-11 Water Meters and Event Counters ...9-12 Type of Pumps ...9-12
Raw Sewage Pumps ...9-12 Other Pumps ...9-13
Friction Loss in a Pipe ...9-13
Friction Loss Example:...9-14 Sensors for Pumps ...9-14 Pump Controls ...9-14 Alarm...9-15 Dual Pumps ...9-15
Designing Pumping Systems ... 9-17
Selecting Pumps ...9-17
Pump Curves ...9-17 Head requirements ...9-19
Fittings as Equivalent Straight Pipe ...9-19 Method 1: Estimating a percentage ...9-19 Method 2: Calculating actual losses ...9-19 Example: ...9-20 Sizing the Pump Tank ...9-20
Dose volume ...9-20
1. Determining Area and Gallons per Inch ...9-20 2. Determining Tank Capacity ...9-20 3. Setting the Dose Volume ...9-21 Example ...9-21 Example ...9-21 Float and Timer Setting ...9-22 Demand Dosing ...9-22 Example ...9-22
Cylindrical Tanks ...9-22 Rectangular Tanks ...9-22 Time Dosing ...9-23 Timer On ...9-23 Timer Off ...9-23
Installing Pumps and Pump Tanks ... 9-23
Pump Tank...9-23
Buoyancy ...9-24
Pump Discharge Assembly ...9-24 Sensors ...9-25 Controls ...9-25 Pump and Alarm ...9-26 Accessible ...9-26 Replaceable ...9-27 Properly Wired ...9-27 Materials for Outdoor Wiring ...9-28 Boxes and Panels ...9-28 Wiring from the pump and alarm controls to the pump and switches ...9-30 NEMA type 1 ...9-31 NEMA type 3R ...9-31 NEMA type 4 ...9-31 NEMA type 4X non-metallic, corrosion-resistant ...9-31
Operation, Maintenance and Troubleshooting ... 9-31
Pumping Costs ...9-32 Calculating Flow ...9-32
Demand Dosed vs. Timed Dosed ...9-32
Dose volume verification ...9-33 Pump delivery rate ...9-33 Troubleshooting ...9-33 The Pump Will Not Start ...9-33 Effluent Stays in the Tank ...9-34
Inspection ...9-34 Evaluating the Pump Tank and Components ...9-34
Safety precautions ...9-34
Abandonment ...9-35
PRETREATMENT ... 10-1
Application... 10-1
Performance ... 10-2
Management of the System ... 10-3
Designing with Management in Mind ...10-3 Economics ...10-4
Product Review and Registration Process ... 10-4
Overview ...10-4
Types of Pretreatment Units ... 10-5
Aerobic Treatment Units...10-5
Definition and Description ...10-5 Rule Requirements and System Classification ...10-6 Treatment Processes ...10-7 Design Basis and Operational Theory ...10-8 Types of ATUs ...10-9
Fixed film ...10-9 Suspended growth ...10-9 Sequencing batch reactor ...10-10 Membrane Bioreactors ...10-11 Performance Levels ...10-12 Applications ...10-12 Management ...10-13 Management plan ...10-14 Installation ...10-15 Troubleshooting ...10-15 Compliance Inspections ...10-16 Abandonment ...10-16 Media Filters ...10-17 Definition ...10-17 Treatment Process in Media Filters ...10-17 Types of Media Filters and Operation ...10-17
Single pass media filters ...10-17 Recirculating Media Filters ...10-18
Applications and Performance ...10-19 Rule Requirements ...10-22
Design ...10-22 Single Pass Sand Filters ...10-22
Daily Flow ...10-24 Sizing ...10-24 Media ...10-24 Underdrain and inspection ports ...10-26 Choosing the containment vessel ...10-27 Peat Filters ...10-28 Final Treatment and Dispersal ...10-30 Design ...10-31 Recirculating Media Filters ...10-31 Recirculating Sand Filter Specifications ...10-34
Installation of Media Filters ...10-36
Containment Vessels ...10-37
Media Filter System Management ...10-38
Management plan ...10-39
Operation Costs of Media Filters ...10-40 Abandonment of Media Filters ...10-40 Troubleshooting Media Filters ...10-41 Compliance Inspections for Media Filters ...10-41
Constructed Wetland Systems ...10-42
Definition and Description ...10-42 Types of Constructed Wetland Systems ...10-42
Open water ...10-42 Hydroponic ...10-42 Subsurface flow ...10-42 Treatment Processes ...10-43 Design ...10-44 Performance ...10-46 Applications ...10-46 Final Dispersal of Effluent ...10-47 Installation ...10-47 Troubleshooting ...10-48 Management Plan ...10-49 1. Effluent levels ...10-49 2. Vegetation ...10-49 3. Effluent quality ...10-50 4. Air supply ...10-50
5. Control of nuisance pests and insects. ...10-50 6. Maintenance of berms and dikes. ...10-50 Winter Operation ...10-50 Compliance Inspections ...10-50 Abandonment ...10-50 Final Treatment and Dispersal of Effluent After Pretreatment Units ...10-51 Disinfection Systems ...10-52
Definition and Rules ...10-52 Disinfection Processes and Design Considerations ...10-55 Methods of Disinfection ...10-55 Chlorination ...10-55 Ultraviolet ...10-56 Ozone ...10-57 Applications ...10-58 Management ...10-58 Chlorine ...10-58 UV...10-59 Ozone ...10-59 Troubleshooting ...10-60 References ...10-60
DISTRIBUTION OF EFFLUENT ... 11-1
Distribution ... 11-1
Supply Pipes ...11-2 Materials ...11-2Schedule 40 and ASTM 3034 ...11-2 Existing Piping ...11-3
Size ...11-3 Slope ...11-4
Installation ...11-4
Freeze Protection...11-6 Cleaning, Priming, and Gluing Joints ...11-7 Cleanout Requirements and Maintenance ...11-7
Gravity Distribution ...11-8
Rule Requirements, Definition and Description ...11-8 Serial Distribution ...11-9
Drop Boxes ...11-9 Management of systems with drop boxes ...11-13 No drop box ...11-14 Continual Distribution ...11-14 Valve Boxes ...11-14 Parallel Distribution ...11-15 Application ...11-15 Distribution Boxes ...11-15 Distribution Box Modifications ...11-16 Management ...11-17 Manifolds and other distribution methods ...11-17 Installation of Gravity Distribution Components ...11-17 Pressure Distribution ...11-18
Purpose and Application ...11-20 Pipe Specifications ...11-21
Supply Pipe and Manifold Requirements ...11-21 Designing the Pressure Distribution System ...11-23 Steps to designing the pressure distribution system ...11-25 Design for pipes at different elevations ...11-28 Installation ...11-29 Manifold construction ...11-30 Distribution piping construction ...11-30 Perforations ...11-30 Management ...11-31 Drip Dispersal ...11-32 Definition and Description ...11-34 Rule Requirements ...11-36 Purpose and Application ...11-36 Design Basis and Operational Theory ...11-37 Sizing ...11-38 Installation ...11-38 O&M and Troubleshooting ...11-39 References ...11-40
SOIL TREATMENT SYSTEMS ... 12-1
Overview ... 12-1
Setbacks ...12-5
Below-Grade Systems ...12-7 Below-Grade Systems: Specifications ...12-8 Trenches ...12-8 Shallow trenches ...12-9 Seepage Beds ...12-10
General Specifications ...12-11
Media Choices ...12-11 Soil treatment system size & long-term performance ...12-11 Distribution pipe ...12-12 Rock/Geotextile ...12-12 Geotextile Fabric ...12-13 Nonrock Soil Treatment System Media ...12-14 Chambers ...12-14 Gravelless pipe ...12-15 Polystyrene beads ...12-16 Other soil treatment media ...12-16
Design Basis and Operational Theory ...12-17 Design of Trenches and Seepage Beds ...12-17
Example Trench Design ...12-21
Dual Field Systems ...12-22 Zoning of Cluster Systems ...12-23 Type II – V Trenches and Seepage Beds ...12-23
Above–Ground Systems ...12-24 Above-Ground Rule Requirements ...12-25 Above-Ground System Siting ...12-25
At-grades ...12-25
Definition and Description ...12-25 General Specifications ...12-26 Design of At-Grade Systems ...12-27 Example at-grade design ...12-32 Mound Systems ...12-34 Definition and Description ...12-34 Locating Mounds ...12-36 General Specifications ...12-39 Mound Design ...12-39
Example mound system design ...12-46
Type III Above-Ground ...12-47
Box Mounds ...12-48 Replacing Mounds ...12-48 Installing Soil Treatment Systems (STA) ...12-48 General Soil Treatment Installation Principles ...12-48 Cover, Topsoil and Vegetation Requirements ...12-51 Trench and Seepage Bed Installation ...12-52
Above-Ground System Installation ...12-53
Construction Equipment ...12-53 Soil Surface Preparation ...12-53 Media Placement ...12-55 Cover Material ...12-57 Inspection of Soil Treatment Systems ...12-58 New Systems ...12-58 Existing Systems ...12-59 Troubleshooting Below-ground Systems ...12-60 Troubleshooting Above-Ground Soil Treatment Systems ...12-62 Reasons for system malfunctions ...12-62 Malfunction due to poor-quality materials...12-62 Malfunction due to poor siting ...12-63 Malfunction due to errors in design ...12-63 Malfunction due to construction errors ...12-63 Malfunction due to system misuse by homeowners ...12-63
Management of All Soil Treatment Systems ...12-64
Management Plans ...12-64
Site planning, preparation, documentation, and contracting ... 12-65
Reading a Drawing ...12-65 Equipment ...12-65 Survey Techniques ...12-66 As-Builts ...12-67 Photographing Installation ...12-68
Notating Your Photographs ...12-68 Building Sewer and Tanks ...12-68 Pump Tank ...12-68 Soil Treatment Site ...12-68
Soil Separation ...12-68 Site Preparation ...12-68 Sand ...12-69 Distribution Media ...12-69 Pressure Laterals ...12-69 Special Considerations ...12-69 Finished Product ...12-69 Contracts ...12-69
Landscaping Septic Systems ... 12-70
Introduction ...12-70 Guidelines for Planting On and Near Septic System ...12-71 Vegetation tables ...12-72 Seeding ...12-74 Sodding ...12-74 Trees and Shrubs ...12-74 References ...12-76
