The French are cleaning up their act and there is a huge raft of rules and regs regarding sanitation which I think most people will agree is a good thing.

Our planning permission insists upon us having a ‘fosse toutes eaux’ which I understand to mean a septic tank – a normal common or garden holding tank that will need emptying every 4 years and in which a bit of bio activity takes place. It’s not a mini waste treatment plant like a Klargester or Eparco doing any grinding or anything fancy. There is a grease trap near the kitchen sink outlet pipe, then the big tank and then an area of gravel beds for the run off. I also note a ventilation pipe that goes from the fosse to the highest part of the roof – a very long run of pipe since the fosse is situated a long way from the house in order to be accessible from the public road. (Could have implications for any MHRV system ???)

I’ve been asking about this run off – but I haven’t had a satisfactory answer. It seems a waste just having it percolate into the ground.

It seems to me that I need to divert the water from showers and baths before it gets to the septic tank into a separate tank that then pumps the water out to the veg patch. That water can be augmented by rainwater captured via rain chains (no gutters permitted on a Provencal house). There are 2 problems with this. Problem 1) expense of another tank. Problem 2) will the French assainissement authorities accept it?

So then, my question to the forum is, how do I get non smelly / contaminated water out of the fosse septique to water the garden?

I’ve looked at the Total France forum but most of the threads there seem to be devoted to emergencies such as having poo back up into showers or finding the fosse in the first place. (Klargesters are not liked).

I have a feeling that you cant do that. In the UK it almost for sure going to be illegal. I is likely to be considered too small a closed loop in terms of nasties.

Were you to go for a reed bed system instead then the water coming out of the end could be pretty clean and for sure OK for veggies.

mrswhitecat
just to pick up on a small point you made. Not sure how you propose to use rain chains without gutters as they only replace the downpipes, or are you using hidden gutters. What is the norm in Provencal for getting the water down from the roof?

Regarding the grey water, I would go with the concept of diverting it before it goes into the septic system. Drain baths, basins,showers etc into a separate system that takes it straight to the garden into a network of irrigation pipes. similarly with urine - perhaps a urinal for the men in the house, or even easier, get them to step into the garden. I'll avoid speculating on how women can get round this one

Separate your grey water from black water. Grey goes to veg plot, black to the tank. The tank should have a leach field which is safe to grow certain crops on. I'd suggest fodder grains (incl carob) for animals, olives, nuts, certain types of beets, crops for ethanol or biodiesel production, firewood coppice. No soft fruits, and be wary of root crops.

Contadino - we've been told we need to keep the gravel beds away from trees. I know olives are very shallow rooted but are you sure they're ok?

Is pre-softened grey water ok for veg? ie water that has been through a water softener (which it will have done).

What it seems I need then is a means of diverting grey water straight out to the garden. (We have a hand pump to empty out sinks and baths into a bucket - but that's really too tedious and I only bother when there's been prolonged drought as I don't believe in watering). I think I am expecting our water consumption to be around 300 litres a day (3 of us + using water saving devices). So it would be really useful to get hold of the water I've merely washed myself or vegetables in to reuse it - especially since I am expecting prolonged droughts.

Asparagus is over now, but for a time ...

The septic tank is always full of water. The solids settle to the bottom, and some of it floats as a 'crust' which can block the incoming flow pipe. It needs emptying (de-sludging) once a year, if you pretend it doesn't it can screw this up a lot worse. sh*t backs up the pipes, the separating 'cloak' at the top of the tank can become dislodged, and you end up with a real nasty load of work that could easily have been avoided. This was the situation with me, as we installed the tank in the first instance and then forgot about it for about 18 months or maybe longer...
sorted it since, and now get it emptied once a year like clockwork. You only need to be up to your elbows in it once to know that you don't want to go through it again.
Just had it done this afternoon in fact, while i was out. No trouble.

Apparently grandma's 'manfriend' has a septic tank and didn't even realise it needed emptying. He'd been in the same place for 10 years. . . . .

Grandma got him to empty it about a year ago. . . . . apparently he'd had no problems before, during or after. . . . . maybe it has something to do with the buildup of 'friendly bacteria'. . . . .mmmmm damdom!

mrswhitecat wrote: "I think I am expecting our water consumption to be around 300 litres a day"

Ah! there's the rub, to coin a phrase. That 300 litres, (we'll look at that figure in a moment) comes off with very little head (i.e pressure to cause flow) so what happens in practice is that it puddles at the first outlet. Therefore to use it for irrigation means collecting and pumping, and that's viable especially if you add harvested rainwater. Actually, rainwayer is oxygen rich and if added to a passive biodigester, i.e. a second tank where the liquor from the septic tank passes through large pebble or purpose designed plastic "pebbles" and then to a settling tank which also stores your rainwater, you have the best of all possible worlds and can then pump anywhere you like onto your veggies or even back to your house for recycling in the WC.

100 litres per day is a design statement for a cheap water economy and you can reduce that easily. A modern dishwasher used once a day will use between 10-13 litres depending on the wash cycle chosen. We use economy and are in the lower band. Don't fit a draining board to your kitchen and you will not be tempted to short circuit the dishwasher. Nothing gets rinsed, in fact, with pill detergents, pre-rinsing accelerates etching of glassware. (Your kitchen will always look neat as well ) Two stage WC flush mechanisms give 3 l for the yellow and 6 l for the brown. Don't buy cheap flush mechanisms as they will pack up after two or three flushes.

Showers instead of baths and ditch those 12" drenching shower heads for a modern head with pinhole jets that will give you a decent shower at flowrates of less than 10 l/min. When I'm between jobs I lead a fairly sedentary life so I only shower every other day. Mind you, that's better than a bath a week in the public baths on the Caledonian Rd. when I was a lad so I feel privileged!

There are washing machines that use water as if there were no tomorrow. Research your options and don't buy on price alone. You sound pretty clued up so I expect I am preaching to the converted. Apologies if I am.

A septic tank is never completely emptied as the crust needs to be preserved. Most experienced operatives know this and pump approx two thirds, taking it from the bottom sludge layer. Doncha just luv the empirical evidence supplied by Domonic. Refilling after emptying an established tank is uneccessary, the soil pressure on the tank walls after some time will have stabilised.

So contadino, can we assume that you've never actually planted a tree in a leach field? Have you ever seen what tree roots do to a fractured mains drainage system?

My cat is a ginger tom called Mickey-me.

OK, OK, OK - enough already!!! Tomorrow I'll arrange to get my septic tank emptied. Last time was 3 years ago. The guy got rid of everything in the tank then, is it really so much better to try and leave the crust?

My waste water is split at source (no need for diverter vaves), all black goes to the septic tank and all grey.....wait for it...goes out of a pipe about 30m from the house straight onto a brick and then bounces onto a bigish slope and soaks in. I am planning to have a soak-away installed this summer but I do worry about the bits and pieces from the sink/dishwasher blocking the soak-away quickly (they currently rot on the surface) - I think I need to find some sort of filter and I will now look up grease traps to see what they are - perhaps I can fit one where the outlet is now and from then pipe it into the new soak away. As for rules, if my builder does it, he must either think it’s OK or know he can get away with it! And from my perspective anything is better than raw grey water pouring down my bank.

The issue of storing grey water has been discussed several time before (sometimes as part of a heat recovery thread) on every occasion 'people' have said it's too fraught with difficulties. I'd post a picture of what grey water looks like, given a little maturating, on my slope but there has already been enough 'detail' in this thread!

Wastetech - you are a star, thanks for the extremely helpful advice. I think it might work, especially the 'advanced filter' - I'll feed the bits and the 5% of the flow used to self-clean the filters, into a very small indeed (say 50cm3) 2 chamber settlement tank (DIY) with metal swing door style pit lid, with over flow going into the soak-away. And, with luck, I'll not need to clean it out that often.