A major reason to maintain your septic system is to save money. Failing systems are expensive to repair or replace, and poor maintenance is often the culprit. Preventive maintenance is a whole lot cheaper than repair or replacement. For example, it could cost up to $40,000 or more to replace a failing system with a new one, compared to approximately $200 to $400 to have a system inspected, and $150 to $250 to have it pumped. Maintaining a septic system is like maintaining a car. A small effort on a regular basis can save a lot of money and significantly prolong the life of the system.

Innovative/Alternative (I/A) systems, although providing more advanced treatment, also require more frequent oversight and maintenance. See Maintaining and Repairing an Innovative/Alternative (I/A) System .

How Does a Conventional System Work?

First, wastewater (from your toilet, sink, tub, etc) flows into your septic tank. Once in the tank, the heavy solids settle to the bottom from sheer gravity, forming a layer of sludge. The lighter solids such as grease float to the top of the tank forming a scum layer. As more wastewater enters the septic tank from the house, the separated wastewater in the middle layer of the tank either flows out or may be pumped into the leaching field (see diagram above). Microorganisms living within the drainfield consume leftover particles and harmful germs and viruses.

The sludge and scum layers remain in the tank where naturally occurring bacteria work to break them down. Since the bacteria cannot completely decompose all of these solids, the layers continue to grow, slowly filling up the tank. These solids will eventually have to be pumped out (see How Often Should I Pump Out my Septic Tank? ).

How do I know if my septic system has failed?


The most obvious system failures leave clues that are easy to spot:

  • Check for pooling of wastewater or muddy soil around your septic tank or drainfield.
  • Check for odors of sewage or a "rotten egg" smell around your system or even in your basement.
  • Notice if your sink or toilet backs up when you flush or do laundry

Check with a septic system professional or your local Board of Health if you have problems with your system. See also: How Failing Septic Systems Can Be Hazardous to Your Health .