A properly functioning septic systems provides primary treatment in the septic tank by retaining solids in the tank and allowing anaerobic digestion by bacteria. Pumping the tank periodically removes any remaining solids.

Liquid effluent leaves the tank and is distributed to a leaching field where it passes through soil. Nutrients such as phosphorous are absorbed after passing through relatively minor amounts of soil. In the relatively hostile environment in the ground, bacteria and viruses die off over time. Effluent becomes cleaner as it continues to pass through soil.

1. The Sewer Line conveying waste from the building to the septic tank.
2. The Tank providing for retention and digestion of solids by bacterial action. The tank has an inlet baffle that directs sewage downward at the inlet end of the tank, and an outlet baffle that prevents scum and solid from floating out to the distribution system at the outlet end. Additionally, septic tanks installed in Connecticut since January 1991 consist of two compartments to allow for an even greater "stilling" effect in the second chamber to allow for a "cleaner" effluent. In 2000, tanks are required to be supplied with effluent filters which are intended to further protect the leach field.
3. The Distribution System piping to convey only effluent as it leaves the septic tank out to the leaching system. Generally, this is conveyed by gravity, but can consist of a pump chamber or siphons if necessary.
4. The Drainage or Leaching System applies sewage effluent to the ambient soils on site. Currently, stone filled trenches, stoneless chambers; plastic and concrete galleries and leaching pits are most common in use.

Once the engineers know how far to spread out a system, they have a range of leaching products to choose from to take advantage of the best soils while minimizing septic fill and expense.

• Keep accurate records about location and cleaning of system, and put a copy of your "as-built" in a sealable plastic bag and hang it from your basement sewer pipe.
• If tank is 3-4 feet below ground level, simplify inspection and cleaning by installing a 20-24 inch manhole about 12 inches below ground level. (Most recently installed tanks are just 6-12 inches below ground and this would make a manhole unnecessary.)
• Pump your tank and have your system inspected at least every 3 to 5 years by a licensed septic contractor. This recommendation is every 2 years with 2 compartment tanks or if baffle filters (required in 2000) are used.
• Divert roof drains and surface water from driveways and hillsides away from the septic system area. Keep sump pumps and house footing drains away from the septic system.
• Take leftover hazardous household chemicals to your approved hazardous waste collection center for disposal. Use bleach, disinfectants, and drain and toilet bowl cleaners sparingly and in accordance with product labels.
• Educate your family to proper use of the system.

• Use septic system additives offered for sale for the purpose of correcting a malfunctioning system or improving the performance of a septic system. This includes degreasing agents, caustic chemicals, solvents, and "bacterial digestion enhancers" such as enzymes or yeast. These products can be dangerous. Many chemical additives are non-biodegradable and pass through the system into the groundwater, where they can contaminate well water supplies.
• Dump paints, oils, greases, solvents, or pesticides in your septic system. Such wastes may eventually harm well water in the area.
• Discharge the salt brine solution from water softeners into subsurface sewage systems. Connecticut State Department of Health regulations prohibit this. The salt brine may also build up in the ground water and pollute wells and springs supplying drinking water.
• Use matches or an open flame to inspect septic tank; the gases produced by decomposing sewage may explode and cause serious injury.
• Allow trucks or heavy equipment to drive over the tank or leaching field.
• Put a lot of water into the system all at once.
• Do all your laundry in one day. Don't use large amounts of laundry soaps, detergents, bleaches, drain cleaners - recommended quantities should not adversely affect the system. Also, liquid laundry detergents are better than powdered detergents, because the powders never completely dissolve and can clog the leaching fields or septic tank.
• Dispose of bulky items such as diapers, sanitary napkins, paper towels, etc. in your toilet.
• Use a garbage disposal with a septic system. If you must, more frequent pumping (once a year) is recommended.

• Slow running drains or backup into the house of sewage.
• Sewage bleed-out in the area of the system or down gradient.
• Lush green growth over the septic fields (It is normal for the grass to be green there and in dry weather the fields may show up vividly... this caution refers to excessive growth and moisture at the surface).
• Septic odors and bleed-outs after storms.
• Continuous septic odors.