Foreign Perspectives

If there’s one thing that strikes fear into Brits who are thinking of moving to France, it’s the prospect of needing to look after a septic tank.

Why is that though? There’s nothing really that scary about a septic tank. No, the main reason is simply lack of familiarity with septic tanks because many of those moving to rural France are moving from a town and the closest they get to such things is when they flush their toilet.

So what exactly is a septic tank anyway? Very simply put, it’s a method of recycling the waste that you flush down your loo into soil and water that you could drink. No, no joke: if the septic tank is functioning properly then you can drink the water coming out the other end.

Septic tanks come in various forms but the most commonly known in the UK operates as a two tank system. Everything you flush down the loo empties into the first of these tanks where it separates out into three basic components:
1) a sludge which sinks to the bottom;
2) the liquids; and
3) a scum.

The sludge sinks to the bottom and is gradually purified by anaerobic bacteria. One consequence of this is that you should NEVER pour disinfectant down your loo when you’re using a septic tank: this is a sure way of making it smelly.

The liquids run off into the second tank which usually consists of layer upon layer of stones (from large down to sand) which acts as a filter.

The scum forms on the top and will eventually lift the top of your tank if you let it build up long enough. It’s not smelly and makes an excellent fertilizer.

The second tank operates via aerobic bacteria and converts the waste water from the first tank into fairly pure water. A scum layer builds up in the second tank too and after a while you’ll need to shovel off the top layer of this.

So if everything is operating normally, there’s no smell. Where it can go wrong is when someone uses disinfectant in the toilets, thereby killing off the bacteria that make the whole system work and thus you end up with a tank full of **** which obviously smells. Also, if the tank isn’t big enough you can find that it gets overloaded and doesn’t work properly (this can happen if the tank is far too big but is less likely).

In general most people find that they need to get their tanks pumped about every four or five years but, if the tank is the right size, they really only need to take off the top of the scum layer. We had a tank in the UK which functioned without any pumping for over 20 years and just needed us to shovel off the top layer in each tank once.

Hope this lays your fears of septic tanks to rest!

Arnold