When you have a customer purchasing a house with a septic system, it is always wise to get that system inspected to avoid future problems. A lot of homes in this area rely on septic systems to deal with wastewater. As a realtor, you should be prepared when this happens to you. An inspection will be far less expensive than the future issues could be. It's much better to be prepared and know what is going on within your system, than worry in the future when it stops working!