(I am no expert), but there are a few types of systems and you should figure out what type you have. The biggest difference is the aerobic and anaerobic (random article I have not read, but do some research: https://septictankpro.com/difference-between-aerobic-and-anaerobic-septic-systems/), they operate differently and have very different complexities and maintenance requirements.

I have a "jet" system with a stirrer and an air pump - both those require maintenance, electric and will need to be replaced at some point in time. But I don't have leach lines as the effluent runs into the flowing creak on my property. "they" say you can drink the water coming out, but not sure if i'd try...

Depending upon the age and design, they are supper simple just three tanks (around here) not much to go wrong as long as the tanks hold up - but the concrete ones can crack (usually roots or perhaps freezing), and the plastic ones have been known to "float up" although I have never seen or personally heard of it. but there is not much that "can go wrong" it is just a tank.

Now the leach lines that is a totally different story - if you have them (I don't), they can get crushed, over saturated, filled up with solids, etc... so that is where I think I would focus my energy on. Plus being on a lake, be careful about the water table, that might be a MAJOR factor in the requirements and what you can "run" - they don't want "it" to filter into the water too fast and having a high water table means it will get into the water faster...