Private Sewage Disposal Systems - Septic Drawing Library InspectAPedia® -
Septic system drawings, sketches, plans
Illustrations of basic land forms and how they affect septic system installations
Illustrations of septic tanks
Illustrations and sketches of septic system distribution boxes, drainfields, lines
Sketches of leach fields, seepage pits and other onsite waste disposal systems
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Here are some sketches explaining septic system components and installations. These septic system illustrations help readers understand, identify, and possibly even locate buried onsite wastewater disposal
and septic tank equipment at properties.
Some of the illustrations also show why septic systems, particularly drainfields may not be working.
These drawings are for educational purposes and are not engineering plans or specifications. The septic consultants
who are listed at our SEPTIC SYSTEMS HOME can provide that service for both
traditional and alternative onsite waste disposal system designs. Click on the thumbnail sketches below to see each full-sized illustration.
This website is provided as a non-profit public educational
service - intended for on-line study.
Other documents throughout our website include photographs of various septic system components, site conditions, septic test and inspection
tools, etc. To suggest needed sketches or to contribute drawings to this library contact us.
Our main websites are at the bottom of this page.
BASIC LAND FORMS
Basic landforms.
Leaching bed effluent distribution schema
Water table well below leaching beds
High clay, likely problems of limited capacity
Mounding water table subverts leaching bed
RESIDENTIAL SEPTIC TANKS
A typical septic tank , cross section.
Two types of commonly-used pre-cast concrete septic tanks, in cross-section.
Sketch courtesy of Carson Dunlop Associates, Toronto, Ontario
DISTRIBUTION BOXES AND LINES
Typical absorption field (aka leach field, leaching bed).
Distribution Box typical location.
Plan view gives cross section of typical leaching bed trench.
Isometric sketch of tank and distribution lines, gives an idea why you need a distribution box.
ABSORPTION SYSTEMS - Leach Fields, Seepage Pits, etc.
Click on the thumbnail sketches below to see each full-sized illustration.
A somewhat unusual view from the "far-end" of a typical tank and leaching-bed system.
Elevation-view sketch of a tank and drywell or leaching pit or "seepage pit" system used at some older homes. In this illustration the seepage pit
is being used to dispose of septic effluent from a septic tank.
Elevation-view sketch of a drywell or leaching pit or "seepage pit" system used for gray water. In this illustration the seepage pit
is being used to dispose of graywater from non-sewage carrying drains such as a laundry, sink, or shower. Drywells to handle
graywater separately from blackwater (sewage) are often used to reduce the water load on septic systems which have a limited effluent handling capacity.
If the pit shown in this sketch were receiving sewage and blackwater from a building we would call it a cesspool, not a drywell.
Elevation-view and a second, plan-view sketch of common residential tank and leach-field layout.
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The color septic design sketches shown here are courtesy of Purdue's Environmental Education Software Series. Educational software on diskettes is
available from the Farm Building Plan Service, 1146 AGEN Building, Purdue University, W. Lafayette, IN.
SEPTIC SYSTEM DESIGN BASICS: Choosing Septic Tank Size, Absorption System Size - basic septic system volume and absorption system design guides.
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