Dear Purvi
Septic tanks should not be in the south-east, north-east or south-west corner under any condition. If there is paucity of space, the septic tank can be built in the northern corner of the west side, but 30 to 60 cms (1 to 2 feet) away from the compound wall. The length of the septic tank should be in the east-west direction and breadth in the south north, as far as possible.