Robert,

First, let's clarify some thinking and some terms here:

1) "septic tank"

2) "leach field" or "drain field"

3) "septic SYSTEM"

3) "septic SYSTEM" includes both 1) and 2).

Thus, let's start with 1) "septic tank":

Scott, is talking about the "septic tank", and, as Scott said, and as EVERY septic contractor has told me and thousands of others, THE ONLY WAY to inspect a TANK is to remove the cover and pump it out. ONLY THEN can you "inspect it".

Next, let's go to 2) Dye testing tells you nothing about the condition of the tank:

The ONLY WAY to inspect it is to remove the cover to the distribution box and see if water is holding in the box above the drain field connections to the distribution box and if the drain field piping is holding water. Those condition indicate that the "leach field" or "drain field" is not percolating the water down into the soil sufficiently.

[qutoe]NOTE... the only way to test a septic system is with dye...opening a tank and pumping will tell you nothing...after pumping you still need to perform a dye test. Its the only way you can detect failure of the system.