What is a Septic System?

Understand that a septic system is a cafeteria for bacteria. Bacteria are what makes a septic system work. They break down waste, leaving water clean enough to safely percolate down into the earth. The whole system is designed to keep bacteria healthy and busy. Some live in the tank, but most do their work in the drain field.

1. All waste flows to the septic tank. The septic tank acts like a settling pond. Greases and oils float to the top. Heavier solids sink to the bottom. The main chamber on an aerobic system will have two chambers. One of the chambers is for sludge collection and other for aeration.

2. Watery waste, called “effluent,” fills most of the tank. Anaerobic bacteria begin breaking down the organic material in the effluent.

3. A layer of sludge falls to the bottom. Sludge is composed of inorganic solids and the byproducts of bacterial digestion.

4. A layer of scum floats to the top. Scum is primarily composed of fats, greases and oils.

5. A filter prevents most solids from entering the outlet pipe.

6. Effluent flows to the drain field. The drain septic field provides a large area where bacteria can thrive and treated water can seep into the ground.

7. Holes in the drain septic field pipe allow effluent to seep into surrounding gravel. Gravel around pipes allows water to flow into soil and oxygen to reach bacteria.

8. Aerobic bacteria in gravel and soil complete decomposition of the waste.

9. Clean water seeps down into the groundwater and aquifer.

Septic Tank Clean Out: Don’t abuse the system – A septic system that was properly designed and installed needs only occasional ‘pumping’ to remove the sludge and scum from the tank. But without knowing how does a septic tank work, you can do things that harm—or destroy—the system.

  • Waste that decomposes slowly (or not at all) gets flushed down drains. Cigarette butts, diapers and coffee grounds often cause problems.

  • If used heavily, garbage disposers can send too much solid waste into the system.

  • Lint from synthetic fibers flows from washing machines. Bacteria in the tank and drain septic field can’t break it down.

  • Household chemicals like disinfecting cleaners and antibacterial soaps kill bacteria. Most systems can handle light use of these products, but the less you use them, the better.

  • Too much wastewater over a short period of time flushes out the tank too rapidly.

  • Too much sludge reduces bacteria’s ability to break down waste. Excess sludge can also overflow into the drain field.

  • Sludge or scum plugs holes in the pipe.

  • Roots from trees and shrubs can clog and damage a drain field.

  • Compacted soil and gravel block seepage of effluent and deprive bacteria of oxygen. This is often caused by cars driving or parking on the drain field.