1. Poor Soil Conditions; Faulty Design or Installation
A leaching system placed in unsuitable soil, a system that is too small for the house it serves, or an improperly constructed system may lead to early failure.

2. Soil Clogging
If sludge or scum is allowed to escape into the distribution box and from there into the leach field, the soil will quickly become clogged. If this happens, the liquid will no longer soak, or percolate, into the soil. This condition can be caused by broken baffles in the septic tank that allow sludge or scum to escape. Failure to have the tank pumped can also lead to a situation where the sludge and scum overwhelm the baffles.

3. High Water Table
During wet, or abnormally wet, seasons groundwater may rise into the leach field and force sewage upward to the ground surface. This condition may mean the system has to be re-installed at a higher level. It may also be possible to intercept the high groundwater with a series of drains around the system called "curtain drains".

4. Roots
The roots of trees and bushes planted too close to the system can sometimes enter and block the pipes of the system. Removal of the plants and clearing the pipes of the roots is usually required.

5. Physical Damage
Trucks or heavy equipment passing over the system can damage pipes and joints to the point of rendering the system inoperable. You should be aware of the location of the system and direct traffic to avoid such damage.