Originally Posted by Nobby Sapper

Is your "set up" new or long established? It sounds pretty new.
Did you have it put in yourself? Because if the "white clay" is fat then there is no way it should be discharging into a ditch, even if it is via a filter. Foul water should go either direct to a sewer or into a septic tank.
You are lucky that you have noticed the back up in your cellar, because had it reached the ditch you could find yourself looking at a hefty fine for polluting a watercourse.
You need to have your system inspected, and "back jetted" , DON'T HAVE IT BLOWN INTO A DITCH.

Edit, just noticed you are abroad. Discharge away!! Who cares?

In that case there is probably an intermediate pit of some sort in the line between the house and the outflow. You may need a metal detector to search for the Inspection Cover.

Sorry, I am doing several things at once here, watching the Dambusters on TV,, trying to tidy up. You have already siad what you have found.

Originally Posted by Alsacien

Just had a flood in my cellar (luckily nobody was detained there at this point in time).

Source was a concrete 40cm square inspection hatch. Pulled it to find the foot square drain full of water not running away.
Went to the next inspection hatch and pulled that. Just spent the last half an hour digging 5-6 pounds of what looks like white clay out of it. Presumably this is some sort of fat build up from the kitchen/washing machine which joins that drain?

From this drain a 5 inch pipe heads out under the garden 2mtrs deep for about 30 mtrs, and comes out of a bank on the lane and into the ditch.
I think there is a ground filter somewhere in between, as the water coming out into the lane is tested yearly and is OK.
Toilet sewage is going via a septic before joining the ground filter also.

This has happened in the 2-3 years since I last looked into that drain.

How can I sort this in the longer term? Presumably there is a chunk of dislodged fat blocking the outflow which is can be sorted, but I guess my ground filter must be full of the same crud?

If you analyse the Fatty substance, there is probably some mineral or crystals or some product that will break it up by chemical reaction.

Originally Posted by Westpoint

If you analyse the Fatty substance, there is probably some mineral or crystals or some product that will break it up by chemical reaction.

Orthophosphoric acid is always a good starter for ten.

Guys, thanks for all the replies.
This is at my French chalet, built 1977, plumbing and electrics are not the strongest elements of the French nation for sure....
Pipe coming out of bank is 110mm standard grey plastic, leaving the cellar drain is part of the drop in drain, about 80mm cast concrete, will not be able to see what they connected onto it. Under the garden its a good 2 mtrs deep all the way to the lane, so no way to check anything without turning the place into a WW1 battlefield (which it was!!).
When I bought the place I tried to check all the utilities, but the previous owner of 13 years was clueless, so I had to figure everything out myself.
I went digging and found the septic roughly where the previous owner thought it was - all sealed and no way to check inside so I buried it again. Found a 40cm inspection drain 1mtr from it heading to the road, flushing the bog sent a correct amount of clear'ish water on its way towards the road.
The cellar walls have indications of some reworking of the sewage system at some point in time. The norm in the area is to have the whole lot go into the septic, then get it cleaned out every 3 years or so. I think someone changed this in my place at some stage.

I guess jetting is high powered water forced through it? I only 'know' about the ground filter because that is local standard build - using sand and gravel. When I was 'testing' my system to figure it out, I stuck a jet wash in that drain. The water trickles out into the ditch a few mins later, so I'm wondering if jetting will work???

I cannot put any chems into it as the marie test the ditch water 'cos it runs into a stream used by cows etc. My water coming out into the ditch passed the test last autumn, my neighbor failed so they are on it, he put a second septic in at a place easy to get at to be cleaned/emptied in future.

The bio de-greaser sounds like a good long term solution Emsav, PM inbound!

Originally Posted by Alsacien

... I guess jetting is high powered water forced through it? I only 'know' about the ground filter because that is local standard build - using sand and gravel. When I was 'testing' my system to figure it out, I stuck a jet wash in that drain. The water trickles out into the ditch a few mins later, so I'm wondering if jetting will work???

I cannot put any chems into it as the marie test the ditch water 'cos it runs into a stream used by cows etc. My water coming out into the ditch passed the test last autumn, my neighbor failed so they are on it, he put a second septic in at a place easy to get at to be cleaned/emptied in future.

The bio de-greaser sounds like a good long term solution Emsav, PM inbound!

Jetting uses a lance which is passed down the pipe so that the water jet scours the pipe surface. The stuff it dislodges has to go somewhere, so if you do it between the access point and the filter, it will tend to choke the filter. The bio-degreaser does sound like a good idea, but a better one might be to stop pouring the fat from your sunday roast down the sink. As for chemicals, you cannot have looked up orthophosphoric acid, or you would have seen that it does not have any detrimental effects in the water course.

Originally Posted by Joe_Private

Jetting uses a lance which is passed down the pipe so that the water jet scours the pipe surface. The stuff it dislodges has to go somewhere, so if you do it between the access point and the filter, it will tend to choke the filter. The bio-degreaser does sound like a good idea, but a better one might be to stop pouring the fat from your sunday roast down the sink. As for chemicals, you cannot have looked up orthophosphoric acid, or you would have seen that it does not have any detrimental effects in the water course.

Thanks, I will look into orthophosphoric acid options (did not check earlier).

I think the fat is soap based (because its not too smelly), maybe the dishwasher....

The white stuff is fat/washing powder as others have mentioned previously. You can buy a set of rods and rod the drains yourself. If you do rod them, as you push them down the drain, make sure you keep twisting them to the right so they don't become unscrewed in the drain. If it's a bigger blockage you may not be able to rod them and will need to call out a jetting firm. I expect they are readily available from a phonebook or the internet where ever you are. The jet they use isn't your common garden variety but a really high powered industrial machine. Some of the really big ones at high power can smash a brick to pieces. It will cost but needs to be done.

Update.

Got the acid, super duper Jerry version with bottles A and B.
Some water had drained away during the week, but not much.
Poured A then B in via a 40mm tube in the direction of the blockage.
Still blocked this morning.
Went out trying to buy a sectioned cleaning rod - ended up with a chimney sweeping version....
Stuck the brush on, 6 sections to hand, 1mtr in and I hit some sort of trap...
Emptied the water out eventually with a pot, dug out the rest of the white stuff - it is not from the kitchen, it is coming from the washing machine which is 8 mtrs away diagonally across the cellar in another room - concrete floor all the way. Emsav, does the box you mentioned sound suitable for a washing machine? Or is there some special product I should be using?

Stuck the Karcher jet wash down the hole and pressed play, eventually I guess I pushed stuff along enough to get things rolling again.
Now it works, but not with a high amount of water - so I guess I need to contact Pierre le plombier to jet clean as best he can around this trap.....

Are you sure it's a trap? It might be the blockage. Good luck.

Originally Posted by rgjbloke

Are you sure it's a trap? It might be the blockage. Good luck.

Its a flat surface perfectly verticle, with a circa 5cm open part upwards just before it (as felt through a plastic chimney sweeping pole).
I need a local plumber to confirm how these things were constructed in '77, but it makes sense to keep a few cms of water in the drain and to have a trap I guess....