What happens when a septic system fails? How can I tell?

Usually when a septic system fails, the drainfield is not functioning properly. When a
septic tank overflows, the effluent can pass to the drainfield, clogging up the pipes.
This causes sinks and toilets to back up in the house. Other signs include: slow
draining toilets and drains, an odor of sewage, wet area on or near the drainfield, or
contaminated well water.