On 28/07/2020 12:37, NY wrote:
"The Natural Philosopher" wrote in message
...
How often does a septic tank need to be emptied of solids which don't
fully rot down, even though the majority of the liquid is discharged
(after processing) into a soakaway?

Depends how much **** and how manyÂ* sanitary towels you put in..

OK. Two adults. No sanitary towels etc - indeed we are careful to abide
by the "if it's not gone through you, don't put it down the loo" rule,
as well as only using washing up liquid, toilet cleaner and dishwasher
tablets which say they are dishwasher-safe.


Where we lived before, several houses shared a common drain to the sewer
in the road. It was always getting blocked - luckily a fair way
downstream of us so the manhole that became full (or overflowed) was in
someone else's garden. The guys from Yorkshire Water found a huge
blockage of tampons. My wife doesn't use them, and the two other couples
on the same drain are elderly so well beyond needing them. But one of
the other couples had their teenage grand-daughter to stay from time to
time... To avoid singling anyone out, Yorkshire Water sent the same
letter to us all, saying "don't put tampons down the loo" but we all
knew who it was intended for ;-)

All ages are using wet-wipes though, and 'older' people are more
likely to pour fat and grease from cooking down the drain.