Sewage health risk

Tenants informed us a few weeks ago that the driveway pavers were sinking a little... no probs. Yesterday they informed us that a whole section of the driveway has now sunk and the ground around this area is muddy and soft.

And it happens just prior to the plumber going out this morning what appeared to be water started gushing out of the ground and into the yard. Turned out this was sewage not water :eek:.

SA Water acted quickly and have now unblocked their pipe but what happens from here?

I will ring them tomorrow to see about getting the driveway repaired and making the area safe - at their cost.

Is working with sewage a very big health risk and how long before the garden area is safe again, and will I have problems getting them to repair the driveway?

Any tips before I put this demand to SA Water?