Fosse Toutes Eaux

[SilverFeather]

Apologies if this question has been asked before (have searched Forum and can't find answer), does anyone know how often a fosse toutes eaux needs to be emptied? We bought a holiday home last year and are planning to visit it about 8 weeks in total per year - does this make any difference to the number of times it needs emptying?

Thanks in advance for any advice.

[Montcigoux]

It depends of course. If it is a two part system it should also have a bac a graisse located just in front of the tank. The bath, showers and all sinks but not WCs should empty first into the bac a graisse. This traps the grease it simply rises to the top and then the dirty water goes through into the fosse. The bac a graisse with the minor occupation you are planning will need to be skimmed of grease probably only every two years. A thick crust of solid grease forms and basicaly you take the lid off and scoop it out - lovely! You will need to find out if your fosse has or will have one.

Turning to the fosse itself the size is important and what condition it was in when you took over the property if you are not having it installed. Normally it should not require emptying for three to four years. They only really need to be emptied at the point when they stop working properly. You could ask the vendors to have it emptied. Depending on the type of fosse(and there are several types) it may never need emptying. You may need to check the weeper drains from time to time where the cleanish water flows out of the fosse and then is dispersed along a normally herringbone or rectangular patterns of drains. You will also have to find the small circular inspection hatches for the weeper drains. I managed to set one of mine on fire by putting a bonfire on it! If it is the latest sand filter type again it may never need emptying.

Finding out what type it is is the problem. In France everything including the hatches for the fosse and the bac a graisse tend to be buried under soil. If you can't find yours the mairie should have the original application, plans and the name of the installer. Check with the installer as he may have changed his plans on the type of fosse when he dug down. Mine did on the second house where I put one in because he found pure sand. The previous owners may have taken photos so ask them. If you are putting in a fosse take photos and hang onto them. It is surprisingly annoying when you have been digging for a while and you can't locate the exact position of the hatches