SECTION 14 Detailed Directory
Transcript of SECTION 14 Detailed Directory
DETAILED DIRECTORY 14-1
MANUAL FOR SEPTIC SYSTEM PROFESSIONALS IN MINNESOTA
DETAILED DIRECTORY
INTRODUCTION............................................................................................1-1How to Use This Manual ..............................................................................................................1-1
Understanding Septic Systems ..................................................................................................... 1-1Why Are Septic Systems Necessary? .........................................................................................................................1-1
What Do Septic Systems Do?..........................................................................................................1-2
How Does a Septic System Work? ..................................................................................................1-2
Plumbing..............................................................................................................................................1-3Septic tank ..........................................................................................................................................1-3Soil treatment area ..............................................................................................................................1-4Enhancements .....................................................................................................................................1-5
How Is The Sewage Treated? .........................................................................................................1-6
Why Do Septic Systems Fail? .........................................................................................................1-7
Improper maintenance ......................................................................................................................1-7Overuse of water .................................................................................................................................1-7Improper design or installation ........................................................................................................1-7
Cleaning up a Sewage Back-up .......................................................................................................1-8
Clean up tips: ..............................................................................................................................................1-8Compliance Inspections ...........................................................................................................................1-8Abandonment ............................................................................................................................................1-9
Operation and maintenance tips .....................................................................................................1-9
Control water use ...............................................................................................................................1-9Eliminate harmful products from the system .................................................................................1-9Do not use additives ...........................................................................................................................1-9Regularly clean/pump and inspect the septic tank ........................................................................1-9Maintain pumps and filters properly .............................................................................................1-10Protect the soil treatment area ........................................................................................................1-10
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Items to Keep Out of a Septic System ...........................................................................................1-10
Odor Issues and Onsite Sewage Treatment Systems ....................................................................1-11
1. Odors in the home ...............................................................................................................................1-112. Odors near the septic tank .................................................................................................................1-123. Odors near a pretreatment unit .........................................................................................................1-124. Odors near the soil treatment area ....................................................................................................1-125. Odors in the yard .................................................................................................................................1-12
System Performance vs. Program Performance ............................................................................1-13
Local Ordinance Requirements to Permit Performance-Based Systems ..................................1-13Designer Responsibilities: Providing Information to the Homeowner ..............................................................1-13
I. Pre-Design Communication ...............................................................................................................1-13A. Pre-design meeting with system owner ....................................................................................1-13
II. Post-Design Communication ...........................................................................................................1-14A. Final design review ......................................................................................................................1-14B. Management Plan ....................................................................................................................1-14
Installer Responsibilities: Providing Information to the Homeowner ...............................................................1-15I. Pre-Installation Tasks ..........................................................................................................................1-15
A. Agree on establishing the vegetative cover and topsoil. .........................................................1-15B. Septic System Management Plan (select one box) ...................................................................1-16
II. Post-Installation Tasks .......................................................................................................................1-16A. Discuss ponding, run-off, and surfacing. .................................................................................1-16B. Explain and show the system to the homeowner. ..................................................................1-16C. Discuss household water and product use tips with the homeowner. ..................................1-18
Maintainer & Service Provider Responsibilities: Providing Information to the Homeowner ........................1-19A. Septic system Management Plan ..............................................................................................1-20B. During service call, accomplish these tasks and discuss these topics with a homeowner. 1-20C. Communication with the homeowner. .....................................................................................1-21D. Discuss household water and product use tips with the homeowner. .................................1-22
Household Product and Water Use Guidelines for Homeowners ......................................1-22More Information About Septic Systems ...............................................................................................................1-23
Local and Regional .......................................................................................................................1-23
State and National ........................................................................................................................1-24
Publications and DVDs ................................................................................................................1-24
University of Minnesota Bookstore bookstores..umn.edu ................................................................................................................1-25
For More Information .................................................................................................................1-25
References ...................................................................................................................................................................1-25
DETAILED DIRECTORY 14-3
ADMINISTRATION .......................................................................................2-1Federal Requirements ................................................................................................................... 2-1
Overview .......................................................................................................................................................................2-1Management Guidelines .............................................................................................................................................2-1Class V Systems ............................................................................................................................................................2-2Land Application Requirements ...............................................................................................................................2-2
State Agencies ............................................................................................................................... 2-3Overview .......................................................................................................................................................................2-3
Minnesota Pollution Control Agency .............................................................................................2-3
Overview of Minnesota’s SSTS Rules ......................................................................................................2-4System Classifications ...............................................................................................................................2-5
Type I systems .....................................................................................................................................2-6Type II systems....................................................................................................................................2-7Type III systems ..................................................................................................................................2-7Type IV systems ..................................................................................................................................2-8Type V systems .................................................................................................................................2-10Product development permits ........................................................................................................2-10
Compliance Criteria ................................................................................................................................2-10Imminent Threat to Public Health or Safety (ITPHS) .................................................................2-11Failing to protect groundwater .......................................................................................................2-12
Cesspool, seepage pit, leaching pit, drywell ...........................................................................2-13Limiting layer ....................................................................................................................................2-15
Systems Not Operated or Maintained Properly ...................................................................................2-16Systems with flows greater than 2,500 gpd ...........................................................................................2-17Compliance criteria for systems with partial component replacement ...........................................2-17Non-Code System ....................................................................................................................................2-17Inspection Process ...................................................................................................................................2-17Disclosure vs. Inspection ........................................................................................................................2-197083 Certification and Licensing Requirements .................................................................................2-19
Certification ......................................................................................................................................2-20Licensing Exemptions .....................................................................................................................2-20Types of certification and corresponding responsibilities .........................................................2-21
Responsibilities ..........................................................................................................................2-22Responsibilities ..........................................................................................................................2-22
Designer .............................................................................................................................................2-23Responsibilities ..........................................................................................................................2-23
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Inspector ..........................................................................................................................................2-23Responsibilities ..........................................................................................................................2-24
Training .............................................................................................................................................2-24Continuing education ......................................................................................................................2-24Exam ...................................................................................................................................................2-25Experience .........................................................................................................................................2-25
Designer Experience – .............................................................................................................2-25Installer Experience – ..............................................................................................................2-25Inspector Experience - .............................................................................................................2-25Maintainer Experience - ..........................................................................................................2-26
Other Minnesota Regulatory Bodies ......................................................................................... 2-26Board of Architecture, Engineering, Land Surveying, Landscape Architecture, Geoscience and Interior Design ...........................................................................................................................2-26
Board of Water and Soil Resources ..............................................................................................2-26
Department of Health ..................................................................................................................2-26
Existing Conditions – Wells and SSTS ..................................................................................................2-27Isolation Distances ...................................................................................................................................2-27Sewers .......................................................................................................................................................2-27Sumps, Lift Stations, Grinder Pumps ....................................................................................................2-27Setbacks to Sensitive Wells .....................................................................................................................2-27Water Supply Pipes ..................................................................................................................................2-29Abandoned Wells and Abandoned SSTSs ............................................................................................2-29System Compliance .................................................................................................................................2-29
Before July 1, 1974 ............................................................................................................................2-29July 1, 1974 to June 31, 1989 ...........................................................................................................2-29July 1, 1989 to present ......................................................................................................................2-30
Environmental Wells ...............................................................................................................................2-30Variances from the Well Code ...............................................................................................................2-30Source Water Protection ........................................................................................................................2-31
Wellhead Protection .........................................................................................................................2-31Source Water Assessments .............................................................................................................2-34
Department of Labor and Industry ..............................................................................................2-34
Plumbing Code ........................................................................................................................................2-34Occupational Safety and Health ...........................................................................................................2-36Boilers Operator License ........................................................................................................................2-37
Department of Natural Resources.................................................................................................2-37
Department of Transportation .....................................................................................................2-39
DETAILED DIRECTORY 14-5
Local Ordinances .......................................................................................................................... 2-39System Performance vs. Program Performance ....................................................................................................2-40Local Ordinance Requirements for Performance Programs ................................................................................2-41Type I-III Systems ......................................................................................................................................................2-42Type IV-V Systems ....................................................................................................................................................2-42Management ...............................................................................................................................................................2-41References ...................................................................................................................................................................2-44
SEWAGE TREATMENT UTILIZING SOIL .......................................................3-1Impacts of Effluent on Groundwater.........................................................................................................................3-2Soil Treatment Processes ............................................................................................................................................3-2
Biomat ............................................................................................................................................3-3
Soil Treatment ................................................................................................................................3-4
Pathogen Removal .....................................................................................................................................3-4Nutrient Removal ......................................................................................................................................3-5
Nitrogen ...............................................................................................................................................3-5Phosphorus ..........................................................................................................................................3-6
Residence Times .............................................................................................................................3-6
Soil Science Basics ......................................................................................................................... 3-7Soil Defined ..................................................................................................................................................................3-7
What is Soil? ...................................................................................................................................3-7
Components of Soil ........................................................................................................................3-7
Soil Texture ..................................................................................................................................................................3-7Described ....................................................................................................................................................3-7Soil Textural Classification .......................................................................................................................3-8
The twelve soil textural classes ..........................................................................................................3-9Field Determination of Soil Texture ......................................................................................................3-10
Procedure ..........................................................................................................................................3-11Soil Structure ..............................................................................................................................................................3-13
Soil Structure in Minnesota ..........................................................................................................3-13
Soil Structure Description ............................................................................................................3-13
Shape .........................................................................................................................................................3-14Size .............................................................................................................................................................3-15Grade .........................................................................................................................................................3-15
Consistence .................................................................................................................................................................3-17Soil Colors ...................................................................................................................................................................3-17
Significance of Color ....................................................................................................................3-17
14-6 DETAILED DIRECTORY
Determining Soil Colors ...............................................................................................................3-18
Conditions for Measuring Color ...........................................................................................................3-19Reading the Color ....................................................................................................................................3-20
Mottles ..........................................................................................................................................3-22
Redoximorphic Features ...............................................................................................................3-23
Redoximorphic Feature Formation .......................................................................................................3-23Redoximorphic Feature Description .....................................................................................................3-24
Other Soil Features .......................................................................................................................3-24
Nodules and Concretions ................................................................................................................3-24Soft accumulations ...........................................................................................................................3-24Soft rock fragments ..........................................................................................................................3-24Surface features .................................................................................................................................3-24Roots and root traces .......................................................................................................................3-24
Soil Profile ...................................................................................................................................................................3-24Soil Horizons ..............................................................................................................................................................3-25
Determining Boundaries ..............................................................................................................3-26
Soil Morphology ........................................................................................................................................................3-26Soil Pores .....................................................................................................................................................................3-26Soil Permeability ........................................................................................................................................................3-26Saturated Hydraulic Conductivity ...........................................................................................................................3-26Infiltration ...................................................................................................................................................................3-27Plastic Limit ................................................................................................................................................................3-28
Procedure for Determining Plastic Limit in the Field ..................................................................3-28
Porosity .......................................................................................................................................................................3-29Bulk Density ...............................................................................................................................................................3-29Percolation Rate .........................................................................................................................................................3-29Soil Formation ...........................................................................................................................................................3-29
Parent Materials............................................................................................................................3-30
Lacustrine .................................................................................................................................................3-30Alluvium ...................................................................................................................................................3-30Colluvium .................................................................................................................................................3-31Glacial Outwash ......................................................................................................................................3-31Glacial Till ................................................................................................................................................3-31Loess ..........................................................................................................................................................3-31Organic Soils ............................................................................................................................................3-32Bedrock .....................................................................................................................................................3-32
DETAILED DIRECTORY 14-7
Types ..................................................................................................................................................3-32Issues ..................................................................................................................................................3-32
Karst ............................................................................................................................................3-33Preferential flow .........................................................................................................................3-33Soft bedrock ...............................................................................................................................3-33Restrictive ...................................................................................................................................3-33
Climate .........................................................................................................................................3-34
Precipitation .............................................................................................................................................3-34Temperature .............................................................................................................................................3-34
Time of Soil Formation ................................................................................................................3-34
Vegetation and Organisms ............................................................................................................3-35
Plants .........................................................................................................................................................3-35Microorganisms and Soil-Dwelling Animals ......................................................................................3-35
Topography ..................................................................................................................................3-35
Minnesota Soils ..........................................................................................................................................................3-35References ...................................................................................................................................................................3-37
SITE EVALUATION ........................................................................................4-1Overview of Site Evaluation Process ........................................................................................... 4-1
Purpose .........................................................................................................................................................................4-1Overview of requirements ..........................................................................................................................................4-1
Preliminary Evaluation .................................................................................................................. 4-2Gathering Information ................................................................................................................................................4-2Soil Survey Reports and Geologic Atlases ................................................................................................................4-2
Soil Survey Vernacular ....................................................................................................................4-2
Soil Survey In Preliminary Site Evaluation .....................................................................................4-3
Hard Copy Soil Surveys ............................................................................................................................4-4Online Soil Surveys ...................................................................................................................................4-4Detailed Soil Survey Maps ........................................................................................................................4-5
Online availability .............................................................................................................................4-6Saturated Hydraulic Conductivity ...........................................................................................................4-6Linear Extensibility ...................................................................................................................................4-6Water Features ............................................................................................................................................4-6Soil Treatment Areas - Trench, At-Grade, Mound ................................................................................4-7Drainage Classification .............................................................................................................................4-7Slope Phases ...............................................................................................................................................4-7Reading the Soil Survey ............................................................................................................................4-7
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Map unit inclusions ............................................................................................................................4-8Soil Series Limitations ....................................................................................................................4-9
Sand and Rock Fragment Treatment Concerns ....................................................................................4-9High clay content soils: acceptance and smearing concerns ................................................................4-9
Plastic limit ..........................................................................................................................................4-9Above ground system required .......................................................................................................4-10
Slopes ............................................................................................................................................4-10
Water table depths ........................................................................................................................4-10
Permeability..................................................................................................................................4-10
Property Limitations .................................................................................................................................................4-10Determining Homeowner Preferences ..........................................................................................4-10
Setbacks ........................................................................................................................................4-11
Unknown Buried Items ...........................................................................................................................4-13Property lines ...............................................................................................................................4-13
Lot line verification (survey) ..................................................................................................................4-13Easements .....................................................................................................................................4-13
Road right-of-ways ..................................................................................................................................4-13Utility easement .......................................................................................................................................4-13
Dwellings ......................................................................................................................................4-13
Lakes, rivers, streams ....................................................................................................................4-13
Wells .............................................................................................................................................4-14
Ownership ....................................................................................................................................4-14
Legal Land Survey Description ..............................................................................................................4-14Zoning ..........................................................................................................................................4-15
Field Evaluation ........................................................................................................................... 4-16Landscape Position ....................................................................................................................................................4-18
Landscape/Topography ................................................................................................................4-18
Landform ......................................................................................................................................4-18
Hillslope Position and Slope Shape ..............................................................................................4-18
Slope ............................................................................................................................................................................4-19Slope determination......................................................................................................................4-19
Upslope conditions–run-on/diversions .........................................................................................4-19
Slopes, elevations, and benchmarks ..............................................................................................4-19
System orientation to slope ....................................................................................................................4-20Benchmark ...............................................................................................................................................4-20Contours ...................................................................................................................................................4-20
DETAILED DIRECTORY 14-9
Flooding ......................................................................................................................................................................4-20Distance from floodplain ..............................................................................................................4-21
Floodway, flood fringe, and floodplain identification ..................................................................4-21
Vegetation ...................................................................................................................................................................4-22Soil Observations .......................................................................................................................................................4-22
Soil Observations Procedure .........................................................................................................4-23
Soil Observation Log ....................................................................................................................4-24
Limiting layer identification .....................................................................................................................................4-25Redoximorphic features ................................................................................................................4-25
Formation .................................................................................................................................................4-25Identification ............................................................................................................................................4-25Limitations ................................................................................................................................................4-25Recognition of problem soils .................................................................................................................4-26
Red parent material ..........................................................................................................................4-26Thick topsoil ......................................................................................................................................4-26Elluvial horizons ...............................................................................................................................4-27Lamellae .............................................................................................................................................4-27
What do lamellae indicate? ......................................................................................................4-27Is there a thickness criteria where lamellae become limiting? ............................................4-27
Calcareous .........................................................................................................................................4-27Highly decomposed bedrock ..........................................................................................................4-28
Saturated soils ...............................................................................................................................4-28
Water Tables .............................................................................................................................................4-28Soil color determination ..................................................................................................................4-29Soil color implications .....................................................................................................................4-29
Bedrock ........................................................................................................................................4-29
Restricting soil conditions ............................................................................................................4-29
Flood Elevation ........................................................................................................................................4-29Disturbed Areas .......................................................................................................................................4-30
Fill Soils ..............................................................................................................................................4-30Cut Areas ..................................................................................................................................................4-31
Soils, Impacts on ISTS Design ..................................................................................................... 4-31Soil Texture .................................................................................................................................................................4-31
Constructability ............................................................................................................................4-31
Smearing ...................................................................................................................................................4-32Compaction ..............................................................................................................................................4-32
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Soil structure - Preferential movement ...................................................................................................................4-32Soil water movement .................................................................................................................................................4-32
Unsaturated water movement .......................................................................................................4-32
Saturated hydraulic conductivity ..................................................................................................4-33
Determination of percolation rates of most restrictive horizon ..........................................................................4-34The Percometer and the Hook Gauge ...................................................................................................4-35Percolation Test Data Sheet ....................................................................................................................4-35Steps in a Percolation Test ......................................................................................................................4-35Use soil observations to locate suitable area ........................................................................................4-35
Locate an adequate number of test holes.......................................................................................4-36Dig the Test Holes ....................................................................................................................................4-36Prepare the Test Holes .............................................................................................................................4-36Distinguish Between Saturation and Soil Swelling .............................................................................4-37Measure the Percolation Rate .................................................................................................................4-37Calculate the Percolation Rate ...............................................................................................................4-38
Groundwater mounding ...............................................................................................................4-39
Soil Loading Rate .......................................................................................................................................................4-39Soil texture ....................................................................................................................................4-39
Soil structure ................................................................................................................................4-39
Soil consistence .............................................................................................................................4-39
Percolation rate.............................................................................................................................4-39
Basic predictive assessment methods ............................................................................................4-40
Assumptions .............................................................................................................................................4-40Parameters ................................................................................................................................................4-40Application ...............................................................................................................................................4-40Advanced assessment methods ..............................................................................................................4-40
Hydraulic Linear Loading Rate ....................................................................................................4-40
Proper protection of tested area ..............................................................................................................................4-40Staking the Site .............................................................................................................................4-40
Special equipment needed ........................................................................................................................................4-41Equipment limitations ............................................................................................................................4-41Traffic patterns to minimize compaction .............................................................................................4-41Maximum lift/of typical pump trucks ...................................................................................................4-41Winter operation and protection from freezing ..................................................................................4-41
Site Evaluation Reporting Requirements .................................................................................. 4-41Soil and Site Additional Reporting [Over 2,500 gpd] ...........................................................................................4-43
DETAILED DIRECTORY 14-11
Mounding evaluation ...................................................................................................................4-43
Method ......................................................................................................................................................4-43Results .......................................................................................................................................................4-43
Nutrient evaluation .......................................................................................................................4-44
Problem soils assessment ..............................................................................................................4-44
Topographic and site variability evaluation ..................................................................................4-44
Soil property variation and interpretation ...................................................................................4-44
Water table monitoring basics ......................................................................................................4-44
Equipment ................................................................................................................................................4-44Duration ....................................................................................................................................................4-44Proper location .........................................................................................................................................4-45
Problem Sites and Soils .............................................................................................................. 4-45Type I, II, III, IV, and V Systems .................................................................................................. 4-45
Rapidly Permeable Soils ............................................................................................................................................4-45Sands and Gravels .........................................................................................................................4-45
Loamy, Medium, and Fine Sands .................................................................................................4-46
Small Lots ....................................................................................................................................................................4-46General Description ......................................................................................................................4-46
Solutions .......................................................................................................................................4-46
Reduce water consumption or reuse ....................................................................................................4-46Small field with holding tank .................................................................................................................4-46Pretreatment to reduced size drainfield ................................................................................................4-46Time dosing from large pump tank ......................................................................................................4-46Box mound/vertical side wall mound ...................................................................................................4-47
Lack of Unsaturated Soil ..........................................................................................................................................4-47Pretreatment technologies ............................................................................................................4-47
Reduced hydraulic linear loading rate ..........................................................................................4-47
Texture break ................................................................................................................................4-47
Designed perimeter drain tile/curtain drain .................................................................................4-47
Reduce water consumption or reuse ............................................................................................4-48
Disturbed Soil .............................................................................................................................................................4-48Soil modification methods ............................................................................................................4-48
Options ......................................................................................................................................................4-48Excavate out the disturbed soil .......................................................................................................4-48Use of the disturbed soil ..................................................................................................................4-49Manipulate the disturbed soil .........................................................................................................4-49
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Limitations ................................................................................................................................................4-49Effects ........................................................................................................................................................4-49
Design pressure distribution with varying elevation .....................................................................4-49
Valving with management ......................................................................................................................4-49Varying perforation sizes and spacing with valving and management ............................................4-49
Flooding ......................................................................................................................................................................4-49Slowly Permeable Soils ..............................................................................................................................................4-50
60 to 120+ mpi .............................................................................................................................4-50
Soil Descriptions .......................................................................................................................... 4-51Texture ........................................................................................................................................................................4-51Structure .....................................................................................................................................................................4-51Color ............................................................................................................................................................................4-51Landscape ...................................................................................................................................................................4-51References ...................................................................................................................................................................4-52
Appendix 1 - Minnesota Wetland Conservation Act Contractor Responsibility and Landowner Statement Form ............................................................................................. 4-53
WASTEWATER SOURCES AND FLOWS ........................................................5-1Wastewater Sources .....................................................................................................................................................5-1
Sewage ............................................................................................................................................5-1
Definition ...................................................................................................................................................5-1Non sewage sources ..................................................................................................................................5-2
Clear water additions .........................................................................................................................5-2Water softeners....................................................................................................................................5-3Iron filters ............................................................................................................................................5-3How do iron filters work? ..................................................................................................................5-3Can a water softener be used to remove iron? ................................................................................5-4Challenges ...........................................................................................................................................5-4Options ...............................................................................................................................................5-5Reverse Osmosis .................................................................................................................................5-5High-efficiency furnaces ....................................................................................................................5-6Industrial wastewater ........................................................................................................................5-6
Other Establishments .....................................................................................................................5-7
Code Requirements ............................................................................................................................5-8Related Licensing Requirements ......................................................................................................5-8Apartment buildings ..........................................................................................................................5-9Day cares ............................................................................................................................................5-10
DETAILED DIRECTORY 14-13
Commercial kitchen .........................................................................................................................5-10Campgrounds ....................................................................................................................................5-11
Privies ..........................................................................................................................................5-11RV Dump Stations .....................................................................................................................5-11
Laundromats .....................................................................................................................................5-12Office Buildings ................................................................................................................................5-12Schools and Churches ......................................................................................................................5-12Hotels and Motels .............................................................................................................................5-12Medical Facilities ..............................................................................................................................5-12Beauty Salons and Barbers ..............................................................................................................5-13Automotive Garages .........................................................................................................................5-13Filling Stations, Service Stations, Car Washes ..............................................................................5-13Class V Inventory Form (EPA regulations) ..................................................................................5-14
Hydraulics – Flow Rates .............................................................................................................. 5-147080 Versus 7081 .......................................................................................................................................................5-14General Hydraulic Considerations ..........................................................................................................................5-15
Design Process for Flow Equalization...................................................................................................5-16Estimates of Flow for Dwelling Design ..................................................................................................................5-16
Current Use ......................................................................................................................................5-18Architectural Issues ..........................................................................................................................5-18LGU ordinance considerations ......................................................................................................5-19Financial considerations .................................................................................................................5-19Sample bedroom determinations ..................................................................................................5-19
Estimated Flow- Class II – IV Dwellings ..............................................................................................5-20Class II ...............................................................................................................................................5-20Class III ..............................................................................................................................................5-20Class IV .............................................................................................................................................5-20
Measuring Flow for Design and Management .......................................................................................................5-20Water Meters ................................................................................................................................5-21
Installation .........................................................................................................................................5-21Event counter (cycle counter) .......................................................................................................5-22
Elapsed time meter .......................................................................................................................5-22
Other Establishments and MSTS Hydraulic Determinations .......................................................5-23
1. Dwellings ..............................................................................................................................................5-23Per capita applicability .....................................................................................................................5-23
2. Other Establishments ..........................................................................................................................5-24
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Measured Flow ..................................................................................................................................5-27Design Process for Determining Flow ...........................................................................................5-28Design best-practices checklist .......................................................................................................5-29
3. Infiltration from the Collection System ...........................................................................................5-29Waste Characteristics: Waste Strength Components ............................................................... 5-30
Components of Wastewater ..........................................................................................................5-30
Waste Strength .............................................................................................................................5-30
Biochemical Oxygen Demands (BOD5), Dissolved Oxygen, and Total Suspended Solids (TSS) ...................5-31Types of BOD ...............................................................................................................................5-32
Biochemical Oxygen Demand ........................................................................................................5-32Biochemical Oxygen Demand (BOD5) .........................................................................................5-32Carbonaceous Biochemical Oxygen Demand (CBOD) ..............................................................5-33Nitrogenous Biochemical Oxygen Demand (NBOD) .................................................................5-33Ultimate Biochemical Oxygen Demand (UBOD) .......................................................................5-33
Source and Impact of BOD5 on Systems.......................................................................................5-33
Chemical Oxygen Demand (COD)................................................................................................5-34Total Suspended Solids (TSS) .......................................................................................................5-34
Impact of TSS on systems ................................................................................................................5-35Fats, Oils and Grease (FOG) .........................................................................................................5-35
Sources of FOG .................................................................................................................................5-35Impact of FOG on systems ..............................................................................................................5-36
Fat ................................................................................................................................................5-36Oils ..............................................................................................................................................5-36Grease .........................................................................................................................................5-37
Design Process for HSW.........................................................................................................................5-37Biological Treatment Processes ................................................................................................. 5-38
Wastewater Oxygen States ............................................................................................................5-38
Dissolved Oxygen (DO) ..................................................................................................................5-39pH .......................................................................................................................................................5-40Temperature ......................................................................................................................................5-41Alkalinity ...........................................................................................................................................5-42
Pathogens .....................................................................................................................................5-42
Fecal Coliform (FC) .........................................................................................................................5-42Category A Products and Treatment Levels .........................................................................................5-43Category B Products and Treatment Levels .........................................................................................5-44Nutrient Listing ........................................................................................................................................5-45
DETAILED DIRECTORY 14-15
Nutrients ....................................................................................................................................... 5-45MN Rule Treatment Requirements for Nutrients ........................................................................5-45
Nitrogen .......................................................................................................................................5-46
The Nitrogen Cycle in Soil-Groundwater Systems .............................................................................5-471. Nitrogen Fixation ........................................................................................................................5-472. Ammonification ..........................................................................................................................5-473. Synthesis .......................................................................................................................................5-474. Nitrification ...................................................................................................................................5-475. Denitrification ...............................................................................................................................5-47
Health Effects from Groundwater Contamination with Nitrates .....................................................5-48Methemoglobinemia .......................................................................................................................5-48Carcinogenesis .................................................................................................................................5-48Birth Defects ....................................................................................................................................5-48
Surface Water Pollution with Nitrogen ................................................................................................5-49Eutrophication .................................................................................................................................5-49Oxygen Demand through Nitrification ........................................................................................5-49Ammonia Toxicity to Aquatic Organisms ...................................................................................5-49
Biological Nitrification ............................................................................................................................5-49Process Microbiology ......................................................................................................................5-50
Dissolved Oxygen Requirements and Organic Loading Rates .........................................................5-50Suspended Growth Systems ...........................................................................................................5-50Attached-Growth Systems ...............................................................................................................5-51pH and Alkalinity Effects on Nitrification ....................................................................................5-52Temperature Effects .........................................................................................................................5-52Effect of Inhibitors ...........................................................................................................................5-52
Example: Calculation of alkalinity and oxygen requirements for nitrification .................5-52Summary of Nitrification Processes .....................................................................................................5-53Biological Dentrification ........................................................................................................................5-54
Heterotrophic Dentrification .........................................................................................................5-54Wastewater as Carbon Source..................................................................................................5-54Heterotrophic ............................................................................................................................5-54Example: Calculation of stoichiometric equations for nitrate ............................................5-54
Example: Recalculation of stoichiometric equations for nitrate reduction using the wastewater as the carbon source .........................................................................................................................5-55External Carbon Source ...................................................................................................................5-56Example: Design of dentrification system using methanol as the carbon source ....................5-57
14-16 DETAILED DIRECTORY
Example: Design of dentrification system using acetic acid as the carbon source ..................5-58Phosphorus ..................................................................................................................................5-60
Other Components of Wastewater ................................................................................................5-61
Pharmaceuticals ................................................................................................................................5-61Chemicals and hazardous waste .....................................................................................................5-61
Monitoring Wastewater Characteristics ................................................................................... 5-62Certified Labs ...............................................................................................................................5-62
Sampling .......................................................................................................................................5-62
References ...................................................................................................................................................................5-63Appendix 1 ................................................................................................................................... 5-67
Biological Hazards in Wastewater: FAQs for Septic System Professionals ........................................................5-67
PLUMBING AND COLLECTION ....................................................................6-1Introduction ................................................................................................................................... 6-1Definitions ...................................................................................................................................... 6-1
Plumbing .......................................................................................................................................................................6-1Basement sump, grinder and effluent pumps..................................................................................6-1
Non-flush toilets ........................................................................................................................................6-2Flammable waste and sediment traps ..............................................................................................6-3
Maintenance ................................................................................................................................................................6-3Sediment Traps ..........................................................................................................................................6-3Flammable waste interceptor ..................................................................................................................6-5
Maintenance ........................................................................................................................................6-5 Bottom Sand/Sediment Layer Management ...................................................................................6-6
Collection ....................................................................................................................................... 6-6Building sewer ................................................................................................................................6-6
Definition, description, rule requirement .............................................................................................6-6Building sewers ............................................................................................................................................................6-7
Pipe material ...................................................................................................................................6-7
Design............................................................................................................................................................................6-7Pumps in the basement .............................................................................................................................6-7Separation technology ...............................................................................................................................6-7Flammable waste separator ......................................................................................................................6-6Clay and Orangeburg Pipe .......................................................................................................................6-8Ductile Iron ................................................................................................................................................6-8High Density Polyethylene .......................................................................................................................6-8Acrylonitrile Butadiene Styrene ..............................................................................................................6-9
DETAILED DIRECTORY 14-17
Polyvinyl Chloride ....................................................................................................................................6-9PVC Standard Dimensions and Materials ..............................................................................................6-9
Nominal Diameters ............................................................................................................................6-9Iron Pipe Standard - IPS ..................................................................................................................6-10Material Codes ..................................................................................................................................6-10
ASTM International ..................................................................................................................6-10ASTM D1785 - Schedule 40, 80, and 120 ......................................................................................6-10ASTM D2241 - Pressure Rated, Standard Dimension Ratio PVC Pipe ....................................6-10
SDR and Schedule Comparison ..............................................................................................6-11Additional Plastic Pipe Standards ...........................................................................................6-11PW and DWV ............................................................................................................................6-11
Storage and Handling .......................................................................................................................6-12Pipe Marking and Identification .....................................................................................................6-12Pipe Colors ........................................................................................................................................6-12Fittings and Joints .............................................................................................................................6-12Fittings ...............................................................................................................................................6-13
Slope/Grade ................................................................................................................................................................6-14Cleanouts ....................................................................................................................................................................6-14
Setbacks ....................................................................................................................................... 6-15Collection Design .........................................................................................................................6-16
Installation ..................................................................................................................................................................6-17Beginning excavation ..............................................................................................................................6-18
Pipe Cutting .................................................................................................................................6-18
Excavation and Backfilling ......................................................................................................................................6-18Embedment ..................................................................................................................................6-19
Embedment Methods ..............................................................................................................................6-20Finishing ...................................................................................................................................................6-21
Connecting Pipe and Fittings .......................................................................................................6-21
Solvent-Welding .......................................................................................................................................6-21Threaded Connections ............................................................................................................................6-23Mechanical Joints ....................................................................................................................................6-23Gaskets ......................................................................................................................................................6-24Thrust Blocks ............................................................................................................................................6-24
O&M and Troubleshooting ......................................................................................................................................6-24Plugging ....................................................................................................................................................6-25Freezing .....................................................................................................................................................6-25
14-18 DETAILED DIRECTORY
SEPTIC TANKS .............................................................................................7-1Definition and Description ........................................................................................................................................7-1
Physical processes ...........................................................................................................................7-1
Biological and chemical processes...................................................................................................7-2
Treatment achieved with domestic sewage ..............................................................................................................7-2Factors affecting septic tank performance ..............................................................................................7-2
Setbacks .........................................................................................................................................................................7-3Design Impacts and Options ......................................................................................................................................7-3
Tank Sizing for Dwellings ..............................................................................................................7-4
Garbage Disposal and Pumps in Basements ...................................................................................7-5Determining Tank Capacities ...........................................................................................................7-5
Multiple Tanks ............................................................................................................................................7-6Compartmentalization of Single Tanks .................................................................................................7-7
Septic tank sizing for MSTS and other establishments ...........................................................................................7-8Lint filters, effluent screens, and pressure filters ...........................................................................7-8
Tank geometry ..........................................................................................................................................7-9Special 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 ...............................................................................................................................7-11Insulating Tanks .......................................................................................................................................7-13Vehicular Traffic .......................................................................................................................................7-13
Septic tank alarms ......................................................................................................................................................7-13Tees and baffles ...........................................................................................................................................................7-14
Access risers and inspection ports .................................................................................................7-16
Septic Tank Effluent Screens ....................................................................................................................................7-18Tank Construction........................................................................................................................ 7-20
Overview .....................................................................................................................................................................7-20Sewage tank registration ...........................................................................................................................................7-20Materials .....................................................................................................................................................................7-20Structural soundness .................................................................................................................................................7-21
Tank storage, transport, and use ...................................................................................................7-21
Precast concrete septic tanks and sealing materials .......................................................................7-22
DETAILED DIRECTORY 14-19
Pipe penetrations for precast concrete tanks .......................................................................................7-23Rotationally molded polyethylene/polypropylene septic tanks ....................................................7-24
Fiberglass reinforced plastic septic tanks ......................................................................................7-24
Constructing pour-in-place tanks .................................................................................................7-25
Overall Quality of Precast Concrete, FRP, and Poly Septic Tanks.......................................................................7-25Watertightness testing ..................................................................................................................7-26
Hydrostatic testing .......................................................................................................................7-28
Hydrostatic testing procedure for tanks: ..............................................................................................7-28Vacuum testing .............................................................................................................................7-29
Visually examining existing tanks .................................................................................................7-30
Tank labeling ................................................................................................................................7-30
Tank installation ........................................................................................................................................................7-31Safety ............................................................................................................................................7-31
Planning and excavation ...........................................................................................................................................7-31Setting and securing a tank ..........................................................................................................7-31
Installation in high water table conditions ...................................................................................7-32
Dimension/capacity check and the use of existing tanks ..............................................................7-34
Placing and bedding tanks .......................................................................................................................................7-34Insulating tanks ............................................................................................................................7-35
Pipe penetrations .........................................................................................................................7-35
Baffling ........................................................................................................................................7-36
Sealing between joints, inlet and outlet pipes ...............................................................................7-37
Access risers and inspection pipes .................................................................................................7-37
Cleaning accesses .....................................................................................................................................7-37Tank Venting ................................................................................................................................7-38
Backfilling tanks ...........................................................................................................................7-38
Supply pipe ...................................................................................................................................7-39
Final grading ................................................................................................................................7-39
Operation and Maintenance ....................................................................................................................................7-39Tank cleaning .............................................................................................................................................................7-39
Effluent screens .............................................................................................................................7-41
Myths and additives ...................................................................................................................................................7-41Tank inspections and troubleshooting ....................................................................................................................7-42
Odor ..........................................................................................................................................................7-42Evaluating sewage tank performance ....................................................................................................7-43Flow, settling and bacterial action .........................................................................................................7-44
14-20 DETAILED DIRECTORY
Effluent quality .........................................................................................................................................7-45Watertightness ..........................................................................................................................................7-46Baffles ........................................................................................................................................................7-47
Supply lines ................................................................................................................................................................7-48Outlet sewer ..................................................................................................................................7-48
Management of supply lines .........................................................................................................7-49
Tank abandonment ....................................................................................................................................................7-49Holding Tanks, Privies and Graywater Systems ....................................................................... 7-51
Holding Tanks ............................................................................................................................................................7-51Definition .....................................................................................................................................7-52
Rule Requirements .......................................................................................................................7-53
Setbacks and location ...................................................................................................................7-53
Application and Design ................................................................................................................7-54
Capacity ........................................................................................................................................7-54
Floodplain areas .......................................................................................................................................7-54Application and Design ................................................................................................................7-54
Capacity ........................................................................................................................................7-54
Floodplains ...............................................................................................................................................7-54Reduced-size systems ....................................................................................................................7-54
Holding Tank with Drainfield: An Alternative ....................................................................................7-56Installation ...................................................................................................................................7-56
Operation, Maintenance and Troubleshooting ............................................................................7-56
Inspection and Abandonment .......................................................................................................7-56
Privies ..........................................................................................................................................................................7-56Definition .....................................................................................................................................7-56
Rule Requirements .......................................................................................................................7-57
Design and Setbacks .....................................................................................................................7-57
Ventilation ................................................................................................................................................7-57Operation and Maintenance ....................................................................................................................................7-58
Odor Control ............................................................................................................................................7-58Keeping wood odor-free .........................................................................................................................7-58
Troubleshooting ...........................................................................................................................7-59
Odors .........................................................................................................................................................7-59Inspection ....................................................................................................................................7-59
Abandonment ...............................................................................................................................7-59
Graywater Systems .....................................................................................................................................................7-59
DETAILED DIRECTORY 14-21
Definition and Applications .........................................................................................................7-59
Rule Requirements .......................................................................................................................7-60
The following text is courtesy of the Model Decentralized Wastewater Practitioner Curriculum Technology Overview ......................................................................................................................7-61
Segregation of wastewater flows ....................................................................................................7-61
Non-flush toilets ...........................................................................................................................7-63
Incinerating toilet ....................................................................................................................................7-63Composting toilet ....................................................................................................................................7-63Chemical toilet .........................................................................................................................................7-64
References ..................................................................................................................................................................7-65
TANK MANAGEMENT AND LAND APPLICATION .......................................8-1Tank Maintenance .......................................................................................................................................................8-1
Cleaning .........................................................................................................................................8-1
Scum and Sludge Accumulations ............................................................................................................8-1Septic Tank Cleaning Procedure ...............................................................................................................................8-2
How to Clean a Tank......................................................................................................................8-2
1. Locate Maintenance Hole .....................................................................................................................8-22. Open Maintenance Hole .......................................................................................................................8-23. Inspect Contents ....................................................................................................................................8-34. Remove All Tank Contents ...................................................................................................................8-3
Cleaning Procedure ............................................................................................................................8-3Mechanical Mixing ......................................................................................................................8-4Back Flush ....................................................................................................................................8-4
5. Inspect Tank ..........................................................................................................................................8-4Baffles ...................................................................................................................................................8-4Water tightness....................................................................................................................................8-5Inflow from System ............................................................................................................................8-5
6. Replace Maintenance Hole Cover ......................................................................................................8-57. Restore Yard ............................................................................................................................................8-58. Get Paid ...................................................................................................................................................8-59. Proper Land Application of the Septage .............................................................................................8-510. Receipt ...................................................................................................................................................8-611. Improper Maintenance Notice...........................................................................................................8-6
Effluent screens ...............................................................................................................................8-6
Cleaning an effluent screen .............................................................................................................8-7
Troubleshooting an Effluent Screen ...............................................................................................8-8
14-22 DETAILED DIRECTORY
Problems: Professional Cleaning, Not Additives .....................................................................................................8-8Effect of Using Hydrogen Peroxide ................................................................................................8-9
Safety Keys for Maintainers .....................................................................................................................................8-10Safety gear for Maintainers .....................................................................................................................8-10
Safety for Confined Spaces ...........................................................................................................8-11
Hydrogen Sulfide (H2S) ...................................................................................................................8-11Carbon Dioxide (CO2) .....................................................................................................................8-11 Gasoline Fumes ................................................................................................................................8-11
Electricity Hazards ........................................................................................................................8-11
Explosion Hazards ............................................................................................................................8-12Infectious Disease Hazards .............................................................................................................8-12Structural Collapse Hazards ............................................................................................................8-12
Introduction to Land Application ...........................................................................................................................8-12Definitions ....................................................................................................................................8-13
Septage Treatment ....................................................................................................................................................8-16Septage and Its Characteristics .....................................................................................................8-16
Variability of Septage ....................................................................................................................8-20
Restaurant Grease Trap Wastes ....................................................................................................8-20
Potential Complications ..................................................................................................................8-21Transferring 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 .............................................................8-23Pathogen Control Requirements ..................................................................................................8-23
Vector Attraction Reduction Requirements .................................................................................8-25
Lime Stabilization Treatment ......................................................................................................8-25
Pathogen Reduction Alternative #1 for Domestic Septage with pH Treatment Applied to Non-Public Contact Sites .............................................8-28
Crop Restrictions .....................................................................................................................................8-28Grazing Restrictions ................................................................................................................................8-28Site Restrictions........................................................................................................................................8-28
Pathogen Reduction Alternative #2 for Domestic Septage without Additional Treatment Applied to Non-Public Contact Sites ..........................8-29
Crop Restrictions .....................................................................................................................................8-29Grazing Restrictions ................................................................................................................................8-29Site Restrictions........................................................................................................................................8-29
DETAILED DIRECTORY 14-23
Vector Attraction Reduction Alternatives for Domestic Septage Applied to Non-Public Contact Land ........8-29Alternative 1: Injection ...........................................................................................................................8-30Alternative 2: Incorporation ...................................................................................................................8-30Alternative 3: pH Adjustment ................................................................................................................8-30
Site Suitability Requirements for Septage Application .........................................................................................8-31Soil Terminology: Definitions for Septage Application ................................................................8-31
Site Selection ............................................................................................................................................8-32Using the Soil Survey ..............................................................................................................................8-33
Soil Survey Tables: Useful Information for Determining Suitability of Soils for Septage Application ........................................................................................................................................8-34
General Site Management .........................................................................................................................................8-35Allowable Application Rates .........................................................................................................8-35
Land Spreading .............................................................................................................................8-35
Septage Application Rate Limits ...................................................................................................8-36
Additional Nitrogen Management Requirements ...............................................................................8-37EXAMPLE 1: MANA rate determined using option 1 ................................................................8-37EXAMPLE 2: MANA rate determined using option 1 ...............................................................8-37EXAMPLE 3: MANA rate determined using option 2 ...............................................................8-38EXAMPLE 4: MANA rate determined using option 2 ..............................................................8-38
Truck Calibration .........................................................................................................................8-38
EXAMPLE CALIBRATION: ..........................................................................................................8-39Specific Nitrogen Management Requirements: ...................................................................................8-39Hydraulic Loading Rate Limits ..............................................................................................................8-40Maintainer Qualifications .......................................................................................................................8-40
Record Keeping ..........................................................................................................................................................8-40Requirements for Land Application of Restaurant Grease Trap Waste ..............................................................8-42References ...................................................................................................................................................................8-43
Minnesota Pollution Control Agency Offices ......................................................................................8-43
PUMPING SYSTEMS ....................................................................................9-1Overview ........................................................................................................................................ 9-1Pumping Applications .................................................................................................................. 9-1
Pumping in Gravity Systems ......................................................................................................................................9-1Pumping in Pressure Systems ....................................................................................................................................9-3
Sump and Pump Tank Specifications ........................................................................................... 9-4Sump Basket .................................................................................................................................................................9-4Specifications ................................................................................................................................................................9-5
14-24 DETAILED DIRECTORY
Construction ..............................................................................................................................................9-5Discharge line .............................................................................................................................................9-5Sumps for buildings ...................................................................................................................................9-5Covers ..........................................................................................................................................................9-5Single family dwellings ..............................................................................................................................9-5Sump vent ...................................................................................................................................................9-5Clear water sumps .....................................................................................................................................9-6
Pump Tank....................................................................................................................................................................9-6Definition ....................................................................................................................................................9-6Requirements .............................................................................................................................................9-8
Dosing Regimens: Demand vs. Timed .....................................................................................................................9-8Demand Dosing..............................................................................................................................9-9
Timed Dosing .................................................................................................................................9-9
Flow Equalization .........................................................................................................................9-10
Pumps ........................................................................................................................................... 9-11Rule 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 .................................................................................................................................9-12Other Pumps ............................................................................................................................................9-13
Friction Loss in a Pipe ..................................................................................................................9-13
Friction Loss Example:.....................................................................................................................9-14Sensors for Pumps ...................................................................................................................................9-14Pump Controls .........................................................................................................................................9-14Alarm.........................................................................................................................................................9-15
Dual Pumps ...............................................................................................................................................................9-15Designing Pumping Systems ...................................................................................................... 9-17
Selecting Pumps ........................................................................................................................................................9-17Pump Curves ................................................................................................................................9-17
Head requirements .......................................................................................................................9-19
Fittings as Equivalent Straight Pipe ........................................................................................................................9-19Method 1: Estimating a percentage .......................................................................................................9-19Method 2: Calculating actual losses ......................................................................................................9-20
Example: ...........................................................................................................................................9-20
DETAILED DIRECTORY 14-25
Sizing the Pump Tank ...............................................................................................................................................9-20Dose volume .................................................................................................................................9-20
1. Determining Area and Gallons per Inch .........................................................................................9-202. Determining Tank Capacity ..............................................................................................................9-203. Setting the Dose Volume ...................................................................................................................9-21
Example .............................................................................................................................................9-21Example .............................................................................................................................................9-21
Float and Timer Setting ............................................................................................................................................9-22Demand Dosing .......................................................................................................................................9-22
Example .............................................................................................................................................9-22Cylindrical Tanks ......................................................................................................................9-22Rectangular Tanks .....................................................................................................................9-22
Time Dosing .............................................................................................................................................9-23Timer On ...........................................................................................................................................9-23Timer Off ...........................................................................................................................................9-23
Installing Pumps and Pump Tanks ............................................................................................. 9-24Pump Tank..................................................................................................................................................................9-24
Buoyancy ......................................................................................................................................9-24
Pump Discharge Assembly ......................................................................................................................................9-25Sensors ........................................................................................................................................................................9-25Controls .......................................................................................................................................................................9-26Pump and Alarm .......................................................................................................................................................9-27
Accessible ..................................................................................................................................................9-27Replaceable ...............................................................................................................................................9-27Properly Wired .........................................................................................................................................9-28Materials for Outdoor Wiring ................................................................................................................9-28Boxes and Panels ......................................................................................................................................9-29Wiring from the pump and alarm controls to the pump and switches ............................................9-30NEMA type 1 ...........................................................................................................................................9-31NEMA type 3R .........................................................................................................................................9-31NEMA type 4 ...........................................................................................................................................9-31NEMA type 4X non-metallic, corrosion-resistant ..............................................................................9-31
Operation, Maintenance and Troubleshooting ........................................................................ 9-32Pumping Costs .........................................................................................................................................9-32Calculating Flow ......................................................................................................................................9-32
Demand Dosed vs. Timed Dosed ................................................................................................9-32
14-26 DETAILED DIRECTORY
Dose volume verification ........................................................................................................................9-33Pump delivery rate ...........................................................................................................................9-33
Troubleshooting .......................................................................................................................................9-34The Pump Will Not Start .................................................................................................................9-34Effluent Stays in the Tank ................................................................................................................9-34
Inspection .....................................................................................................................................9-34
Evaluating the Pump Tank and Components ...............................................................................9-34
Safety precautions ....................................................................................................................................9-34Abandonment ...............................................................................................................................9-35
PRETREATMENT ........................................................................................10-1Application ................................................................................................................................... 10-1Performance ................................................................................................................................. 10-2Management of the System ....................................................................................................... 10-3
Designing with Management in Mind ....................................................................................................................10-3Economics ...................................................................................................................................................................10-4
Product Review and Registration Process ................................................................................ 10-4Overview .....................................................................................................................................................................10-4
Types of Pretreatment Units ..................................................................................................... 10-6Aerobic Treatment Units...........................................................................................................................................10-6
Definition and Description ...........................................................................................................10-6
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 ..................................................................................................................................................10-9Suspended growth .................................................................................................................................10-10Sequencing batch reactor ......................................................................................................................10-10Membrane Bioreactors ..........................................................................................................................10-11
Performance Levels .....................................................................................................................10-12
Applications ................................................................................................................................10-12
Management ...............................................................................................................................10-14
Management plan ..................................................................................................................................10-14Installation..................................................................................................................................10-15
Troubleshooting .........................................................................................................................10-15
Compliance Inspections ..............................................................................................................10-16
Abandonment .............................................................................................................................10-17
DETAILED DIRECTORY 14-27
Media Filters .............................................................................................................................................................10-17Definition ...................................................................................................................................10-17
Treatment Process in Media Filters ............................................................................................10-17
Types of Media Filters and Operation ........................................................................................10-17
Single pass media filters ........................................................................................................................10-17Recirculating Media Filters .................................................................................................................10-18
Applications and Performance ....................................................................................................10-20
Rule Requirements .....................................................................................................................10-22
Design .....................................................................................................................................................10-23Single Pass Sand Filters .........................................................................................................................10-23
Daily Flow ........................................................................................................................................10-24Sizing ................................................................................................................................................10-25Media ...............................................................................................................................................10-26Underdrain and inspection ports .................................................................................................10-27Choosing the containment vessel .................................................................................................10-29
Peat Filters .............................................................................................................................................10-29Final Treatment and Dispersal .............................................................................................................10-31Design .....................................................................................................................................................10-32Recirculating Media Filters .................................................................................................................10-32Recirculating Sand Filter Specifications .............................................................................................10-35
Installation of Media Filters .......................................................................................................10-38
Containment Vessels .............................................................................................................................10-38Media Filter System Management ..............................................................................................10-39
Management plan ..........................................................................................................................10-40Operation Costs of Media Filters ................................................................................................10-41
Abandonment of Media Filters ...................................................................................................10-41
Troubleshooting Media Filters ...................................................................................................10-42
Compliance Inspections for Media Filters ..................................................................................10-42
Constructed Wetland Systems ..............................................................................................................................10-43Definition and Description .........................................................................................................10-43
Types of Constructed Wetland Systems ......................................................................................10-43
Open water ......................................................................................................................................10-43Hydroponic .....................................................................................................................................10-43Subsurface flow ...............................................................................................................................10-44
Treatment Processes ...................................................................................................................10-44
Design ........................................................................................................................................10-45
14-28 DETAILED DIRECTORY
Performance ................................................................................................................................10-47
Applications ................................................................................................................................10-48
Final Dispersal of Effluent ..........................................................................................................10-49
Installation..................................................................................................................................10-50
Troubleshooting .........................................................................................................................10-50
Management Plan .......................................................................................................................10-52
1. Effluent levels ..............................................................................................................................10-522. Vegetation ...................................................................................................................................10-523. Effluent quality ............................................................................................................................10-524. Air supply ....................................................................................................................................10-525. Control of nuisance pests and insects. ....................................................................................10-526. Maintenance of berms and dikes. ............................................................................................10-52
Winter Operation ..................................................................................................................................10-52Compliance Inspections .......................................................................................................................10-53Abandonment ........................................................................................................................................10-53
Final Treatment and Dispersal of Effluent After Pretreatment Units ...............................................................10-53Disinfection Systems ...............................................................................................................................................10-54
Definition and Rules ...................................................................................................................10-54
Disinfection Processes and Design Considerations.....................................................................10-57
Methods of Disinfection .............................................................................................................10-57
Chlorination ...........................................................................................................................................10-57Ultraviolet ...............................................................................................................................................10-58Ozone ......................................................................................................................................................10-59
Applications ................................................................................................................................10-60
Management ...............................................................................................................................10-60
Chlorine ..................................................................................................................................................10-61UV............................................................................................................................................................10-61Ozone .....................................................................................................................................................10-62Troubleshooting .....................................................................................................................................10-62
References .................................................................................................................................................................10-63
DISTRIBUTION OF EFFLUENT .....................................................................11-1Distribution .................................................................................................................................. 11-1
Supply Pipes ................................................................................................................................................................11-2Materials .......................................................................................................................................11-2
Schedule 40 and ASTM 3034 ................................................................................................................11-3Existing Piping .........................................................................................................................................11-3
DETAILED DIRECTORY 14-29
Size ...............................................................................................................................................11-3
Slope .............................................................................................................................................11-4
Installation .................................................................................................................................................................11-4Freeze Protection ..........................................................................................................................11-6
Cleaning, Priming, and Gluing Joints ..........................................................................................11-7
Cleanout Requirements and Maintenance ....................................................................................11-7
Gravity Distribution ..................................................................................................................................................11-8Rule Requirements, Definition and Description ..........................................................................11-8
Serial Distribution ........................................................................................................................11-9
Application ...............................................................................................................................................11-9Drop Boxes ...............................................................................................................................................11-9
Management of systems with drop boxes ...................................................................................11-13No drop box ....................................................................................................................................11-14
Continual Distribution .........................................................................................................................11-14Valve Boxes .............................................................................................................................................11-14
Parallel Distribution ...................................................................................................................11-15
Application .............................................................................................................................................11-15Distribution Boxes .................................................................................................................................11-15
Distribution Box Modifications ....................................................................................................11-16Management ............................................................................................................................11-17
Manifolds and other distribution methods .................................................................................11-17Installation of Gravity Distribution Components ......................................................................11-17
Pressure Distribution ..............................................................................................................................................11-18Purpose and Application ............................................................................................................11-20
Pipe Specifications ......................................................................................................................11-21
Supply Pipe and Manifold Requirements ..........................................................................................11-21Designing the Pressure Distribution System .......................................................................................................11-24
Steps to designing the pressure distribution system ..................................................................11-26Design for pipes at different elevations .................................................................................................................11-29Installation ................................................................................................................................................................11-30
Manifold construction ...................................................................................................................11-30Distribution piping construction .................................................................................................11-30Perforations .....................................................................................................................................11-30
Management .............................................................................................................................................................11-31Drip Dispersal ..........................................................................................................................................................11-32
Definition and Description ..................................................................................................................11-34
14-30 DETAILED DIRECTORY
Rule Requirements ................................................................................................................................11-36Purpose and Application ......................................................................................................................11-36Design Basis and Operational Theory ................................................................................................11-37
Sizing ...............................................................................................................................................11-38Installation .......................................................................................................................................11-38
O&M and Troubleshooting .................................................................................................................11-39References .................................................................................................................................................................11-41
SOIL TREATMENT SYSTEMS ......................................................................12-1Overview ...................................................................................................................................... 12-1
General Requirements ............................................................................................................................12-3Setbacks ........................................................................................................................................12-5
Below-Grade Systems ................................................................................................................................................12-7Below-Grade Systems: Specifications ......................................................................................................................12-8
Trenches ....................................................................................................................................................12-8Shallow trenches ..............................................................................................................................12-9
Seepage Beds ..........................................................................................................................................12-10General Specifications .................................................................................................................12-11
Media Choices ........................................................................................................................................12-11Soil treatment system size & long-term performance ...............................................................12-11Distribution pipe ............................................................................................................................12-12Rock/Geotextile ..............................................................................................................................12-12
Geotextile Fabric ....................................................................................................................12-13Nonrock Soil Treatment System Media .......................................................................................12-14Chambers .........................................................................................................................................12-14Gravelless pipe ................................................................................................................................12-15Polystyrene beads ...........................................................................................................................12-16Other soil treatment media ...........................................................................................................12-16
Design Basis and Operational Theory ........................................................................................12-17
Design of Trenches and Seepage Beds ........................................................................................12-17
Example Trench Design ........................................................................................................................12-21Dual Field Systems .....................................................................................................................12-22
Zoning of Cluster Systems ..........................................................................................................12-24
Type II – V Trenches and Seepage Beds .....................................................................................12-24
Above–Ground Systems ..........................................................................................................................................12-24Above-Ground Rule Requirements .....................................................................................................12-25Above-Ground System Siting ...............................................................................................................12-25
DETAILED DIRECTORY 14-31
At-grades .....................................................................................................................................12-25
Definition and Description ..................................................................................................................12-25General Specifications ...........................................................................................................................12-26Design of At-Grade Systems ................................................................................................................12-27
Example at-grade design ...............................................................................................................12-32Mound Systems ........................................................................................................................................................12-34
Definition and Description ..................................................................................................................12-34Locating Mounds ...................................................................................................................................12-36General Specifications ..........................................................................................................................12-38
Mound Design ...............................................................................................................................12-40Example mound system design ....................................................................................................12-46
Type III Above-Ground ..............................................................................................................12-47
Box Mounds ....................................................................................................................................12-48Replacing Mounds ..........................................................................................................................12-48
Installing Soil Treatment Systems (STA) ..............................................................................................................12-48General Soil Treatment Installation Principles ..................................................................................12-48Cover, Topsoil and Vegetation Requirements ....................................................................................12-51Trench and Seepage Bed Installation .................................................................................................12-51
Above-Ground System Installation .............................................................................................12-52
Construction Equipment ......................................................................................................................12-53Soil Surface Preparation ........................................................................................................................12-53Media Placement ...................................................................................................................................12-55Cover Material .......................................................................................................................................12-57Inspection of Soil Treatment Systems .................................................................................................12-57
New Systems ....................................................................................................................................12-57Existing Systems .............................................................................................................................12-59
Troubleshooting Below-ground Systems ............................................................................................12-60Troubleshooting Above-Ground Soil Treatment Systems ...............................................................12-62
Reasons for system malfunctions .................................................................................................12-62Malfunction due to poor-quality materials..........................................................................12-62Malfunction due to poor siting .............................................................................................12-63Malfunction due to errors in design .....................................................................................12-63Malfunction due to construction errors ...............................................................................12-63Malfunction due to system misuse by homeowners ...........................................................12-63
Management of All Soil Treatment Systems ...............................................................................12-64
Management Plans ................................................................................................................................12-64
14-32 DETAILED DIRECTORY
Site planning, preparation, documentation, and contracting ............................................. 12-65Reading a Drawing ..................................................................................................................................................12-65Equipment ................................................................................................................................................................12-65Survey Techniques ...................................................................................................................................................12-66As-Builts ....................................................................................................................................................................12-67Photographing 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 .......................................................................................................................................12-68Site Preparation ......................................................................................................................................12-68Sand .........................................................................................................................................................12-69Distribution Media ................................................................................................................................12-69Pressure Laterals ....................................................................................................................................12-69
Special Considerations ................................................................................................................12-69
Finished Product ........................................................................................................................12-69
Contracts ...................................................................................................................................................................12-69Landscaping Septic Systems ..................................................................................................... 12-70
Introduction .............................................................................................................................................................12-70Guidelines for Planting On and Near Septic System ..........................................................................................12-71Vegetation tables ......................................................................................................................................................12-72
Seeding .............................................................................................................................................12-74Sodding ............................................................................................................................................12-74
Trees and Shrubs ......................................................................................................................................................12-74References .................................................................................................................................................................12-76
FORMS AND REFERENCE SECTION ...........................................................13-1Table IX and IXa: loading rates and absorption ratios from MN Rules Chapter 7080.2150, Subp. 3 (E) .......................................................................................................................................... 13-1
Estimate of Waste Strengths from Other Establishments ............................................................. 13-2
Equations and Constants .................................................................................................................. 13-3