Fri, 22 May 2026 19:06:27 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26710#Comment_26710 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26710#Comment_26710 Fri, 11 Jul 2008 13:24:44 +0100 mrswhitecat
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).]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26726#Comment_26726 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26726#Comment_26726 Fri, 11 Jul 2008 13:57:32 +0100 ludite
I'm sure someone more qualified will tell me why this idea won't work.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26731#Comment_26731 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26731#Comment_26731 Fri, 11 Jul 2008 14:19:18 +0100 tony
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.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26737#Comment_26737 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26737#Comment_26737 Fri, 11 Jul 2008 14:48:56 +0100 ludite https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26748#Comment_26748 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26748#Comment_26748 Fri, 11 Jul 2008 16:52:39 +0100 Terry 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 ]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26823#Comment_26823 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26823#Comment_26823 Sat, 12 Jul 2008 14:52:38 +0100 marktime
The output from a septic tank is a black, foul-smelling liquid called liquor, and is the product of anaerobic processes. It requires further treatment and that takes place in the leach field (reed beds, gravel beds, etc.) which are relatively oxygen-rich environments. i.e. aerobic processing. You can short-circuit this treatment plan with proprietry mini-treatment plants that theoretically yield fluids fit to drink, (Luis Pasteur's words!), well anyway, fit to discharge into waterways. Unfortunately, mini plants require an energy source to power at least a small pump. I have seen large scale biodigesters use a 100 mm pebbles bed and no power source in sight relying on gravity but that's out of the question for you.

Your grease trap is fundamental and needs to be cleaned monthly, and good septic tank maintainance requires that they be emptied annually and don't believe anything you hear to the contrary. Grey water should be piped separately and routed to the leach field as well. Your sanitation health depends on maintaining an impeccable leach field, (and it helps your wallet as well, as relaying the leach field is a costly venture). Make sure your septic tank is sited close to where the collecting lorry can gain access and away from your house as emptying is usually a smelly operation.

Harvesting grey water has never seemed like a long term succesful operation to me as it always gets smelly eventually, but I'm willing to be wrong if anyone else has a positive story to tell.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26951#Comment_26951 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=26951#Comment_26951 Mon, 14 Jul 2008 16:19:17 +0100 contadino https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27080#Comment_27080 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27080#Comment_27080 Tue, 15 Jul 2008 17:10:34 +0100 mrswhitecat
PS - this is not our house design - it's the one that came with the planning permission on the land. Coming from a damp climate we never miss the opportunity to remind the builder / architect that we don't want to be living with buckets and leaks.

I know how much men and boys enjoy peeing in the open air. I plan to have a straw bale in the compost heap to aim at. I hope it will keep the wild boar at bay too. I don't want them tromping all over the veg plot. Ladies' urine is less useful I understand (too many artificial hormones) so there'll be no al fresco opportunities for the sisterhood.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27084#Comment_27084 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27084#Comment_27084 Tue, 15 Jul 2008 17:36:27 +0100 mrswhitecat
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.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27085#Comment_27085 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27085#Comment_27085 Tue, 15 Jul 2008 17:43:07 +0100 ludite
regarding wee. Is it only us. . . . .but: I've found that hubby can pee in the loo - no smell. . . . .I can peee in the loo - no smell. . . . . . . but if the 2 pees should combine before we flush. . . . . .DYNAMITE!!!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27087#Comment_27087 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27087#Comment_27087 Tue, 15 Jul 2008 17:50:42 +0100 mrswhitecat https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27107#Comment_27107 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27107#Comment_27107 Tue, 15 Jul 2008 19:07:05 +0100 mrswhitecat
I've been back to the French forum - and it does seem that most people wait until there is an unholy emergency before doing anything.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27119#Comment_27119 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27119#Comment_27119 Tue, 15 Jul 2008 20:15:33 +0100 Dominic Cooney 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.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27120#Comment_27120 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27120#Comment_27120 Tue, 15 Jul 2008 20:20:39 +0100 Albert https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27140#Comment_27140 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27140#Comment_27140 Tue, 15 Jul 2008 22:05:07 +0100 ludite
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!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27170#Comment_27170 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27170#Comment_27170 Wed, 16 Jul 2008 05:20:02 +0100 contadino
http://www.reuk.co.uk/Water-Two-Greywater-Diverter-Review.htm

Olives have wide and deep roots. For the big trees, mine go down at least 6m, which is one reason for how they continue to perform in our arid climate. I wouldn't put gravel beds near them, as the trees don't like them, and I doubt it's good for stability.

My pozzo nero is the straight down vertical type - a concrete box, 4m deep, with an open bottom - which is the 'old fashioned' design. It's never been emptied in 60 years, and (touch wood) should never need to be. I know people who have the new type (prefabricated, with a leach field) and grow comfrey, olives, almonds, carob, and food for livestock on the leach fields. You can see where the underground pipes run as the rest of the garden is dry tinder all summer, with a neat pattern of lush green growth where the pipes have been sunk.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27186#Comment_27186 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=27186#Comment_27186 Wed, 16 Jul 2008 09:58:09 +0100 marktime
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.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=77526#Comment_77526 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=77526#Comment_77526 Fri, 12 Mar 2010 07:45:42 +0000 wastetech https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=77640#Comment_77640 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=77640#Comment_77640 Fri, 12 Mar 2010 22:43:35 +0000 Gotanewlife
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!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=78145#Comment_78145 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=78145#Comment_78145 Mon, 22 Mar 2010 07:26:59 +0000 wastetech
Take a look at http://www.rainwater-harvester.com as they sell some decent filters.

Grease traps are really for grease, unless you buy the 'basket' type that also traps the food scraps, but they are a pain (and very smelly) to empty.

It is better to leave the crust as it takes quite a long time to build up, contains a lot of very good aerobic bacteria which help to digest the floating solids, stops the tank contents from becoming too septic and blocks the smell of the septic liquor underneath.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=78179#Comment_78179 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=2123&Focus=78179#Comment_78179 Mon, 22 Mar 2010 13:45:41 +0000 Gotanewlife