You will want to ask the age of the system, and when it was last pumped.
A septic system consists of a septic tank that fills first -- the "solids" sink to the bottoms and the water drains off through perferated pipes into the "leach field". The leach field is fairly easy to locate, especially during a drought, because it will be the part of the yard with the greenest grass. All that fertilized watering !! At some point, the septic tank will become full and it needs to be pumped out, and yes, there are people who do that for a living. (yuck)
Environmentally, they are fine. Because I have a septic tank, I use white toilet paper, I use joy dishwashing soap and biodegradeable cleaners in my house. Other than that, the good news is that without a sewer hook-up, you don't have to pay a sewer bill. :-) We have a well and a septic tank, so our water and sewer are both private, and I really like it that way. All the water we use returns to the ground and is recycled without being chorinated, chemically treated, etc.
When one puts in a septic tank, (new construction) one has to have a percolation test to be sure the soil drains well enough for a septic system, and the perc test will also determine the type of system used. When the septic system is installed, it also has to be certified before the house can be built.
Simple Green is a good biodegradable disinfectant to use. And Shaklee has a full line of cleaning products, ALL of which are biodegradeable.