My relatives live in a very rural area, and have a septic tank that they
share with their neighbours, like this:
[3 houses]->[2 chamber septic tank]->[settling tank]->[leach field]
I don't know if I've used the correct words. Rainwater from the houses
also runs directly in the "settling tank", which is just a
concrete-block lined hole in the corner of their field. The houses are
uphill of the "leach field", which helps.
The "leach field" appears to consist an unknown amount of perforated
100mm pipe running underneath their field. The perforated pipe seems to
be totally clogged up with something - maybe silt, maybe roots of
numerous trees planted since the leach field was installed.
To stop the settling tank from overflowing, my relatives have dug a
30cm x 30cm x 20m trench in their field, which handles all the run-off
from the "settling tank". Is this a really bad idea from a public health
point of view?
I'd quite like to hire a mini-digger for a few days, and install a new
leach field - is that a DIY job?