New septic tank installation - Part 1

I've divided this into two parts as I have a lot of photos and thought it might be interesting for some (those of you in France who might one day get the dreaded 'fail' at inspection time!) to see just what is involved.

A bit of background: those of us out in the sticks don't have main sewerage. That means we have to get rid of our toilet waste and grey water somehow. In the past that may have meant a halfway decent septic tank system, a cess pit, a pipe running into a ditch or even worse, just piped straight into a river! So France is cleaning up its act and trying to comply with EU regs and that means we now get inspections every 4 years or so to check out our waste disposal. Whilst we passed OK 5 years ago, last year some jobsworth decided our septic tank for toilet waste only, and separate grease trap for grey water, both of which ran into a soakaway and then into the ditch (which is where our stream overflow runs until it goes under the road and continues on as a stream) was no longer acceptable. Fair enough really. Except WE have to foot the bill, and if you can get it in at under €6000 that means you are probably doing the work yourself.

We chose to have a traditional sand filter bed as it is a lot cheaper than biorock, which is a less disruptive but much more expensive way to filter the water coming out of the septic tank. Plus biorock requires maintenance costs too. In a way after seeing the disruption here we kind of wished we had gone for that option, but at the same time it would have required taking out a horse chestnut tree and probably a lot more breaking up of bedrock, so that would have ended up costing us about €10K. As it is, we ended up paying €8K, which is a lot more than it was originally going to cost (although that does include about €400 for new gravel which he kindly fetched for me from a quarry).

The before. I never planted here after a couple of trees fell, due to honey fungus and old age,
because I knew that one day this might have to become a sand filter bed.

The start of the digging out of the sand filter bed.

At first it went well with nice soft soil which was easy to dig;
hitting bedrock came later.

The cats thought it was great fun -
Harry taken through the kitchen window in the evening of the first day!

One corner of the filter bed square was solid rock!

David, the Scottish guy doing our installation after the filter bed hole was completed.

The filter bed gets filled with an enormous amount of sand. That's Harry again.

Who thought the sand was great for rolling in.

By day 4 David had realised this was not going to be a quick job and enlisted the help of
a friend for a couple of days. That's the pipework for the filter bed on the lawn.

Nice mess of pipes going around the old grease trap which was crumbling
and also leaking! Here we have two pipes for rainwater,
two pipes for greywater, and a pipe for the air vent from the tank
which is going up the side of the house in a corner.

The hole for the septic tank. 3/4 of this was solid granite and took many hours
to break up with a rock breaking attachment on the digger
(the reason it cost so much more). It then started filling with water
as I guess we were down level with the ditch outside.

On top of sand goes a layer of thick gravel and that is our new air vent on the corner of the roof.

The pipework in place and more gravel added.
You are only allowed 8" (20cm) of soil on top of this.

Here comes the fun bit. The old septic tank gets pumped out.

And cleaned too, because this will now be my 4000 litre rainwater tank!

5th day - half naked Frenchman starts filling in the filter bed with topsoil
and creating our strange mound in the lawn.

The new tank being part filled with tap water to hold it in place
(and which thanks to new regs only needs to be 3000 litres, thus saving us a hell
of a lot of money as more rock would have had to be broken up to get
a larger tank in! You can see the ground water in the bottom;
this was pumped out umpteen times but just gushed back!

Round the front of the house the toilet waste pipe had to be located and was discovered
that it had been cemented in place which is a big no-no, adding more time and work.
The rainwater pipe also had to be located so it could be diverted.

And here we are at the end of the first week with a temporary toilet pipe going
slightly uphill so we could use the loo during the long Pentecost weekend!

Continues in Part 2.