How & Where to Look for Septic System Components: tank, D-box, drainfield InspectAPedia® -
Where to look for septic system components during a septic inspection & test
How to perform a septic loading & dye test, step by step
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This chapter explains where to look for and how to locate septic system components as part of the Septic Loading and Dye Test procedure for testing the function of
septic systems.
Septic System. Our page top photo shows a recently-created pile of rocky soil pushed against trees and over the "septic tank" location at a rural property. This act of burying the septic tank right before the inspection raised an immediate concern about just what was installed at the property.
The failed soil absorption system (drainfield) for this system was promptly found simply by climbing over this rock-pile and looking over the edge of the hill. More photos of this troubled septic system are below.
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LOOK FOR SEPTIC COMPONENTS - Where, When, How Look for Septic System Components as Part of a Septic System Inspection & Test Procedure
Possible Septic Tank Locations: what are the likely locations for a septic tank? See HOW TO FIND A SEPTIC TANK for details of how to find the septic tank. See DOCUMENT TANK LOCATION for examples of how people may have made a record of where to find the septic tank at a property.
Shared septic systems What are all of the possible locations for a tank on the property? Perhaps there is
essentially none, or room for a tank but no absorption system. Do not assume that all septic components are even on the property. Some older properties were built with shared septic systems, or individual tanks and a shared leach field.
Later owners may never have been told that their leach field was on a neighbor's property, and vice versa. See Drainfield Location for detailed procedures for finding the septic drainfield or leaching bed (also called soakaway field) at a property.
Space for septic fields? Is there even room for a conventional tank and drainfield at this property? If the property is too small it is unlikely to have a septic tank and drainfield but it might be using a cesspool. Beware: a "grandfathered" cesspool or other non-conforming septic system at a property may not be permitted to continue in use in that form when septic repair is needed.
Are there site encumbrances likely to make installation or replacement of the septic system difficult or costly, such as
nearby streams or lakes, storm drains, trees, rocky or steep site conditions (see our septic failure case examples),
or limited distances from a well or property boundary?
Remember to check nearby
streams and lakes during and after the dye test. Are there pipes extending from the property into a nearby stream, possibly
discharging septage?
The site shown in this photo was all that was available to place a septic system. Rocky and steep, a
conventional system could not work properly (though special steep slope septic system designs are available.
This system
appeared to be in failure before we started our test - we saw water, probably septic effluent running over a rock just
below the reported (new) septic tank.
Our dye confirmed that it was from the septic system.
Here is the same rock ledge with increased effluent flow as soon as we started our septic test. Sewage from this
system had been discharging to the surface from an overflow pipe or from the bottom of a tiny, home made seepage pit which itself
was sitting on solid rock, sending septic effluent running downhill to Wappingers Creek and from there to the Hudson River
for decades.
We were informed by the agent that the system was in perfect working order but that the owners, simply
to improve the "curb appeal" of the property, had just installed a new septic tank. Unfortunately what was needed was an entire
steep slope system to handle the effluent.
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Thanks to Alan Carson and Bob Dunlop, Carson Dunlop, Associates, Toronto, for permission to use illustrations from their publication, The Illustrated Home which illustrates construction details and building components. Carson Dunlop provides home inspection education, publications, report writing materials, and home inspection services. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.
Pollard Water source of septic system testing tracer dyes
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