We have a reasonably-sized septic tank embedded in the front garden and we understand that the previous owner had it cleaned every year, at a cost of about £120. There has been a suggestion that this annual cleaning is a bit excessive. On the other hand, I have read that if the solids mount up and leave the tank and move into the soakaway area then the soakaway area becomes clogged and you then have to build a new septic tank at another (clean) spot - which is a real bother and a considerable expense. So, clearly, regular cleaning is worthwhile.
But how often is regular for a two-person household?
Any ideas?
Thanks, Eddy.