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?

Had a similar problem a few years ago and ended up digging up the offending pipe and replacing it as it was collapsing - wrecked the garden!!! Would strongly advise getting a CCTV survey on your system especially if the pipes you can see are not of the 110/160mm plastic variety. The CCTV survey will locate the "ground filter" which my man thinks will not be blocked as you say water is coming out of the discharge on your bank and into the ditch. He suggests that if the survey reveals no major problems that the system is "jetted" to clear any remaining blockages. After which you might consider fitting a Domestic Biomass Grease Trap between your final kitchen waste outlet and your cellar. We fitted one on the recommendation of our sewage contractor, cost about 300 Euros.

Regards
Emsav

PS: PM me where you are in the 88, my man has found something that might be of use to you but it needs refining to keep the cost down.

The white muck is 'fat' from the kitchen sink etc
As previously said needs somebody with the kit to sort out the drain?
You don't say where you live, so have you got insurance? either one of those all in gas, electric, water type £17 pm or house hold policy which just might cover drain blockages. If not get one for the future because 'Fat' is the biggest cause of drain blockages going.

I used to do work for a lettings agent in Manchester about 30 odd years ago, and they looked after a large complex of flats in Didsbury..... mainly occupied by elderly jewish widows.

I never booked in any jobs on Mondays, 9. 05am, regular as clockwork, phone went, "Vinnie can you go down to Ballbrook Court, the drains are blocked at beep, beep, beep, beep, beep and beep.

Always chicken fat and tea leaves, just where they hit the cold water in the U- bends outside.

Bloody great start to the week, 6- 10 drains at 20 quid a pop, especially after I found this antique drain cleaner designed for this, didn't even need to bend down, the rest of the week was just jam on it.

What you could do is buy a set of Chimney sweep type rods (perhaps they are a dual purpose thing for both Chimney sweeps and drain cleaners)

Then go down to the outflow end, and slowly push one of the attachments up the pipe, until you detect the blockage. Wiggle the attachment about a bit to dislodge any fat material.

You can get the pack of rods, complete with several attachments, From B&Q, Wickes, or hardware shops or Plumbers Merchant.

The only problem with the rods, is if you give it large with the plunger thing fitted, especially if there is an undiscovered cover nearby and you launch sewage into the garden. That said, they are invaluable. The white stuff could be fat, probably is, washing powder also clogs up the works too.

This mob has some good stuff:-

Chimney Cleaning

Alascien, Is the pipework "old" like Cast Iron or is it new, like plastic.

Is there an Inspection Cover half way between the house and the outflow?

Westpoint - just so you are aware, the plumbing where Alsacien abodes is several hundred miles away from where you find B&Q, Wickes, and quite probably English 'standards' of plumbing.

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?