The value of a drain scan can be seen by a recent survey carried out on a property locally with misaligned joints and rats within the drainage system. In addition, it became clear that there were no traps within the drains which were not immediately obvious from the outside. In addition, the rainwater drainage system was combined with the foul drainage system which was a septic tank. This will mean that the septic tank will not be efficient as it will not biodegrade materials and ordinary rainwater will turn into foul water which will then disperse into the ground and cause ground contamination. It is important that foul drainage and rainwater drainage systems are separate when there is a septic tank.