When it’s full…right?
While that seems like the obvious answer, its not quite so straightforward. Septic tanks operate at a full, or what is considered “normal” operating level. This is a good thing and allows your system to function properly and maintain a healthy bacterial colony. This means as your household waste and water comes out of the home and enters your system an equal amount of liquid exits your tank and is dispersed to the leach field. Keeping your septic tank in a full state allows a healthy bacterial colony to grow and thrive on all the solids that are deposited along with the waste water.
But, what about when I need an inspection?
Generally speaking, your system shouldn’t need to be pumped to perform a septic inspection. Except for a few specialty types of systems, your inspector can complete their inspection without needing to have it pumped. There are many components considered when your inspector looks at the health of your system, so while it can be necessary
So, when is it time for the tank to be pumped?
It depends. A healthy system can last many years, but it depends on your household’s usage and activity. As the system is used, sometimes the bacterial colonies can’t keep up with the amount of solids added to the tank. Or maybe some things from the Do Not Flush list went down the drain. When these solids (scum and sludge) build up too much it allows them to escape and flow out into the leach field and can cause the system to slow down, and even create blockages. As a general guideline when more than 12 inches of solids (scum or sludge) are measured in the tank, its a good time to get it pumped. This is something your inspector will check for you using a shovel or specialty tool called a sludge judge.
Don’t worry if you’re not due for an inspection and are wondering how to know when to have it pumped. As long as you haven’t noticed anything unusual with your system (smell, slow drains, water pooling), its probably doing just fine.
