Answer :
According to Vastu Shashtra the suitable place of septic tank in a house North West and South East to East direction is good. It should not touch house wall and house boundary. It is two - five feet a way from the house wall.
I'm currently in the process of building a bungalow. Septic tank in this house is placed below the entrance. Where the Septic Tank should be placed according to Vastu?