If you are buying a home with an on-site waste disposal system or septic tank, you should consider having it inspected by a professional septic contractor. A typical NJ home inspection does not include this type of specialized, intrusive inspection. To properly inspect the system, the qualified septic contractor will need to dig holes to access the underground parts of the system. This will include visually inspecting the interior of the tank, as well as testing the leach field.
It makes good sense to have the tank pumped at the time of this inspection. A professional septic contractor can perform both the inspection and pump the tank, killing two birds with one stone and assuring that you begin with an empty tank and a system that has been inspected. Often, you can negotiate with the seller to have them pay for the pumping.