tbod

Thanks for your reply - clearly good advice.  However, before I go in search of professional advice, I would like to get a better idea of how my system works. Anyone out there with a similar system (see my original letter)?

I am confused!  In my cellar there are two interconnected concrete tanks.  The first is fed directly from the toilet via an internal pipe. The second tank has an outlet pipe which seems to go through the wall of the cellar into an open drain.  Rainwater and 'grey water' are also fed into this open drain via separate external down-pipes. There doesn't seem to be any way of emptying either of the tanks.  I have not seen a system like it anywhere else.  We were told, when we purchased the house, that a regular dose of Eparcyl would be all that is necessary to keep the system running.  Can anyone enlighten me as to what sort of system I have - and whether it will need upgrading?  Unfortunately, we do not own any of the land adjacent to the house where a new fosse septique could be located - any upgrade would have to be cellar-based.  Advice please  !!!