I dwell in a 25 unit apartment complex in Coimbatore.
The septic tank which is 14 ft in length and 9 feet deep get frequently filled up despite regular cleaning.
We do not have a underground drainage system (UGD) from the municipality in our area and the current system is that the sewage is absorbed by earth.
Soak pit is made of big stones as wall and an unplastered bottom
Suggested line of action for a functional soak pit and septic tank
Thanks,
Gururajan