[timlin]

However, if the system isn't maintained it often needs replaced at a large expense. Most homeowners don't know how to inspect and don't bother to hire someone knowledgeable.

Our local township has an ordinance where every residential sewage system (10k residents, not sure how many systems that is) has to be pumped out and inspected by a certified sewage hauler. This way, the homeowner knows about and is required to make simple repairs before the entire system fails.