Septic Systems

Septic System InfographicSeptic systems dispose of wastewater on-site. View the Environmental Protection Agency's (EPA) Septic System Owners Guide (PDF).

Main Components

A septic system has two main components: the septic tank and an absorption area (i.e. leach field).

Septic Tank

The septic tank is often buried about six feet deep and ten feet away from the building. A septic tank has two chambers. The solids are collected in the first chamber which settles to the bottom of the tank, while the fats and oils float to the top. The liquid remains in the center which then flows to the second chamber. The second chamber is connected to the leach line which takes the liquid to the absorption field for percolation into the ground.

Absorption Area

While bacteria in the tank help to break down the solids, many chemicals, viruses and other contaminants remain in the liquid effluent. The soil acts as a natural filter to remove some of the bacteria and viruses. Most of the liquid from the absorption field eventually seeps down to the groundwater. An unmaintained/poorly functioning system contributes greater amounts of contaminants into the ground. One way you can protect our groundwater is to establish a maintenance schedule for your septic system.


How many years has it been since the septic tank was pumped and inspected? If your answer is two or more, it may be time to call for an inspection.

Tips to Remember

  • Inspect/pump your septic tank every 2 to 4 years. Keep a record of septic maintenance.
  • Do not dump the following down the drain:
    • Harsh Chemicals
    • Oils
    • Paints
    • Pesticides
    • Pharmaceuticals
  • Do not use system additives. Although they claim to prolong the life of your system, they are unnecessary and can actually damage your system.
  • Avoid toilet bowl cleaners, tablets that contain "benzene" (i.e. dichlorobenzene or formaldehyde.) They can destroy the bacteria in your system.
  • Chemicals used to clear clogged drains or leach lines (to destroy roots) can harm your system by killing the bacteria. Avoid products that contain acid.
  • Don't use your septic system as trash. Minimize waste by disposing of paper products and food waste in the trash. Use your garbage disposal system sparingly.