A septic tank is important to have if you live off of the municipal sewer line. You have to have somewhere for the wastewater you generate at your house. If your septic tank stops working, then you are stuck because you can't flush your toilet, run water down your drains, or do laundry. That's why you need to know what some of the signs of a failing septic tank are. That way, you can be proactive when you see them and try to head off the problems before they get worse.