Advice on fosse please

[dave21478]

Hi, Ive been in this house several months but never even looked at the fosse system except a cursory glance when the old owner showed me it and said it worked 100% without intervention and advised against bleach etc.

 

So, Im in a ground-floor appartment with a gite above me and another gite next door. Since yesterday, whenever I put a significant amount of water (emptying a sink or running a washig machine) down a drain either in my place or the upstairs gite, I get loud bubbling noises from my plumbing and black and orange goo coming up into the bath.

My new game of tapdancing in the shower to avoid the lumps rapidly lost its appeal so today I had a look at the fosse.

Under lid number 1 is what appears to be some kind of grease reclamation system - 3 consecutive concrete basins the water flows through, with the orange goo im getting in the shower floating on the top. A poke with a stick revealed the bottoms of these basins to be filled with the black sludge too. I assume I need to empty these yes? Do I just dredge the lot out? any precautions (apart from the gloves etc) any other servicing I need to do while Im at it?

 

Under lid number 2 was what looked remarkably like a giant home-made chocolate cake. Obviously the main poo tank. A tentative poke with the stick revealed the chocolate cake looks to be infact a sort of crust, with something much less appealing underneath. Is this layering normal? The level is maybe a foot below the top of the tank - is this normal operating level or does it need emptied? No nasty smells when in use and everything seems fine otherwise.

 

Any advice appreciated,

Dave.

 

 

 

[Gyn_Paul]

The first one is the fat trap,  this needs emptying periodically.  Do you have a long garden with no neighbours? You could skim the contents, barrow it down the garden and dump it. The birds will eat some of it (I know. gross!!). The second chamber is either the fosse septique or a holding tank. The crust and the level are what one would expect when its working. What you didn't mention (and the deciding factor) is the depth of the 'contents' under the crust. The bacterial action breaks down the solids and other organic matter which flow into it, but over the years it silts up with inorganic matter (one plumber told me this is 90% soil and grit washed off your hands or washed out of your clothes, which is why old systems which had just the loo going into the fosse only needed emptying about once every Preston Guild). This you can't dump.

If you are getting the contents of the fat trap backing up then it sounds like a blockage in the flow between there and the fosse. Does the loo flush properly? Or does the water level rise frighteningly up the pan?

Sounds like a system emptying is in order. Find your local Assainissement (sp?) on www.'pagesblanch.com and get them both emptied. It will cost you about 150 euros. If you ask them they'll flush a high-pressure hose down the drain between the two chambers (assuming they are some distance apart). Normal service should be resumed.

Of course, if it's not a fosse toutes eaux, then you should be replacing the system anyway to comply with the latest draconian regulations.

p