Septic Tank Basics & Septic Systems
Septic tank systems are the standard method for disposal of human wastewater in many suburban and rural areas. The simplest type of septic system, invented before the septic tank, is called a cess pit or cess pool and consists of a pit in the ground into which sewage is dumped. Some percentage of the solids are digested in the cess pit, and the remaining fluid seeps out into the ground.
A more modern disposal system is a septic tank with leach field (leech field). In a common septic-tank configuration, a home's toilets, sinks and showers are piped to a buried concrete, fiberglass or polyethylene tank. A discharge pipe leads away from the septic tank to a buried perforated pipe or network of pipes, known as a leach field or leech field. Pipe elevations are such that the septic tank remains almost full at all times, which permits bacteria to "digest" virtually all the solids that enter the tank. The remaining liquid is dispersed into the soil through the perforated pipes.
The most common failure mode for septic systems is that the soil around the leach field becomes impervious (clogged) to the flow of water. When this happens, the water level in the septic tank increases and plumbing fixtures in the house refuse to drain properly (sewage backs up).
A variety of chemicals containing microbes, acids and enzymes are sold that attempt to open up the soil pores in the leach field and get the septic tank system working again.
Chemicals and mechanical methods can be used as a Do It Yourself method to keep your septic tank working. If they prove inadequate you may need to call in a professional to evaluate the situation.
