LARGER VIEW of septic dye breakout at a basement entry from a failed septic system buried below a driveway during conduct of a septic loading and dye test
- an expert can find clues and perform tests that reduce risk of a costly surprise How to Perform a Septic Loading & Dye Test
Septic Testing Procedures Home Page

  • SEPTIC DYE TEST PROCEDURE - CONTENTS: How to conduct a septic system loading & dye test - this septic testing protocolis used by most home inspectors and septic test consultants - How to perform a septic loading & dye test, step by step
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Septic dye testing procedural guide:

This article series provides the detailed procedure explaining just how to inspect and test a septic system.

We give details of the Septic Loading and Dye Test procedure for testing the function of septic systems, focused on condition of the effluent disposal section, also known as a leach field, seepage pits, drainfield or drainage field.

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HOW TO PERFORM a SEPTIC DYE TEST - How to Properly Conduct a Septic Loading and Dye Test

septic dye going down a toiletSeptic System Loading and Dye Tests often requested by certain lenders, involve flushing a special dye down a toilet or other drain combined with a known quantity of water sufficient to put a working load on the absorption system.

If waste water leaks to the ground surface (an unsanitary condition indicating serious septic failure) one may find dye in that water provided the septic system is flowing at common rates.

Dyed effluent usually appears in 20-30 minutes on a failed system but can take up to five days to show up. If at a building inspection suspect wet areas are observed I recommend a dye test even if one was not previously requested.

When wet areas are not found (or created by running water into the septic system) on the property being inspected, dye tests may still be performed to meet requirements of some lenders.

Although this test can often find a costly failure it does not find all possible problems. So by itself a dye test is not indicative of complete condition of the system. On the other hand, I've found so many failed systems with this procedure that it's well worth performing.

Watch out: Anyone inspecting septic systems MUST be familiar with the hazards and safety concerns discussed at SEPTIC SYSTEM SAFETY WARNINGS

Septic dye tests involve flushing a special florescent dye down a toilet or other drain. The dye itself does not make anything happen. It is simply a colored indicator that can identify water found outside as having come from the fixture where the dye was introduced.

It's the volume of water introduced into the system that forms the actual "test". If waste water is coming to the surface (an unsanitary condition indicating serious septic failure) one may see dye in that water, provided the septic system is flowing at common rates.

When suspect wet areas are observed, if the system has no maintenance history, if the area is known to have problem soils, or if other historic or site conditions raise question about the condition of the system we recommend that the inspector perform a dye test.

A septic loading and dye test will by no means find every septic failure, but this methods finds many failures that otherwise are unnoticed by a home buyer until shortly after moving-in. Septic loading and dye tests are complimentary to and should precede any further inspection steps taken such as pumping the septic tank.

WHEN TO PUMP THE SEPTIC TANK - After, not Before Septic Tests are Performed

After a loading and dye test (which primarily tests the absorption system, leach field, or drain field), unless the septic tank has been pumped very recently, we recommend that this additional step be taken.

Before completing the purchase of a property with a septic tank and absorption system, limited but important additional information regarding the condition of the system tank and also the leach field may be obtained by having a septic contractor open, clean, and inspect the septic tank itself.

Particularly in the case of older systems that have not been serviced, if the property owner will permit this step we recommend it. When the tank is pumped, ask the pumping contractor to describe the size, type, and condition of the tank and its components, and also to tell you if s/he saw any indications that the system needs repair or that the tank or leach system are at or near the end of their life.

Do not permit the septic tank to be pumped before the septic loading and dye test - that will prevent a valid test of the system and in particular, prevents loading of the drainfield. More details about the problem of septic tank pumpouts as a cover-up of a septic problem or failure are at Don't Pump Before Testing Septic Systems: warnings for home buyers about septic tank pumping.

The links given below describe the details of how to perform a septic loading and dye test, procedures, observations, water quantity, and septic dye quantity.


Continue reading at SEPTIC TEST PRE-CHECKS or select a topic from the More Reading links shown below.

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SEPTIC LOADING & DYE TEST PROCEDURE at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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