How Do I know When to Empty my Septic Tank?
Well, if your back garden is covered with foul liquid and grey paper waste and your toilets won't flush properly then I'd say it's probably time to make that emergency call!
Fortunately this doesn't happen very often but there are a couple of signs to watch out for if you suspect your tank is getting full.
The first is unusual sewage-like odours around the tank. The septic tank uses the vent pipe on your drain system - you know the open stack pipe running up the wall by the bathroom- to ventilate at high level to disperse any smells. If the inlet or outlet of the tank is blocked then the tank will ventilate locally- usually around the manhole and you will get that unmistakable smell.
The second is that your toilet is slow to flush away or the sinks are slow draining. Now, this might well be because of a partial blockage in the drain upstream of the tank. There's an easy test - lift an upstream manhole, if you can see the pipe goes back to being empty after running some water down the drain then the drain is not blocked in the pipe. It might still be blocked in the "T" piece connector inside the tank (this directs effluent down into the tank) so lift the lid of the tank and expose the top of the "T" piece. Get a garden cane or piece of wood -2by2 is ideal and gently poke the wood through the T piece. If It's blocked this should move the obstruction and you could well see a flush of sewage enter the tank.
Whilst you have the tank open then test for the solids level in the tank. If your piece of wood is long enough lower it into the tank, push it through the scum layer that should be floating on the top of the liquid; you should feel some slight resistance as it lands on the solid layer; push a little further and you'll then find the bottom of the tank. Withdraw the stick and - carefully, so as not to touch the stick- see how much solid is on the bottom of the tank. If there's more than 30cm or 1 foot in old money then it's time to empty the tank.
As you can see, none of this is rocket science; in fact there are no hard and fast rules about when to empty a tank. Our earlier post gives some ideas about how often to empty the tank.
When you do decide to empty the tank then please, contact an experienced, licensed and knowledgeable operator to do the dirty deed! You can contact us on 01900 870140 at any time to discuss servicing your septic tank.