A septic system works by collecting all of the waste water from your home and allowing natural forces to treat it. Most septic systems use no electricity and few mechanical components. They work using gravity, time, and natural biological activity.
The waste water first collects in your septic tank where it is held for a day or more to allow most of the solid waste to settle to the bottom of the tank. A layer of greasy scum will also accumulate on top of the effluent in the septic tank. The waste water then flows into your leach field where it is dispersed throughout the field and percolates into the soil.
The septic tank has a series of baffles that are designed to hold the solids and the greasy scum layer in the tank, but allow the water to flow into the leach field. The solid material in the tank decomposes to some extent, but over time solids accumulate in the tank and the level of solids builds up.
If amount of solid material in the septic tank grows too large, the septic tank will not have enough room to hold the water long enough and the water that flows out to the leech field will carry increasing amounts of solid material. These solids will clog the leach field and the soil surrounding the leach field and slow the rate of percolation.
Eventually the soil and leech fields will be overwhelmed and the septic system will fail. Untreated waste water will puddle on the surface and your drain line will back up. Regular septic tank pumping will help prevent these problems.
