Septic and Wells

Nobody wants to flush a toilet into a drinking water supply. It’s important to install and maintain septic systems properly to avoid polluting groundwater. Typical septic systems have three parts:

  • Septic tank: Household wastewater is collected and stored in a concrete, metal, plastic, or fiberglass tank just outside the house. The tank stores solids that float to the top or settle to the bottom. The remaining liquid flows into the drainfield. If tanks are not pumped periodically, floating solids may overflow into the drainfield and clog pipes and soil.
  • Drainfield: The drainfield is made up of a grid of pipes that spread the liquid over a wide area. Holes in the pipe allow liquid to leach into the soil.
  • Proper soil: The soil is the single most important purifying step in a septic system. Soil microorganisms and plant roots need air and time to break down bacteria, viruses, and nutrients and purify liquid waste. Septic systems fail when soils are too wet, clogged, or compacted to absorb the liquids or too well-drained to have enough time to purify liquids.

Septic System Maintenance

Contrary to popular belief (or wishful thinking), septic systems are not maintenance-free. Half of all septic system failures are due to poor maintenance. Signs of neglect include backed-up plumbing, lush grass over the drainage field, and smelly seepage. Long before you see these signs, the system may discharge untreated sewage into the groundwater and into your well!

To extend the life of your septic system:

Inspect the solids in septic tank annually.Insert a probe into the inspection port in >the tank lid. If solids (usually black >specks) cover the probe more than one third >of the tank depth, it’s time to pump.>

Pump the tank every 1 to 5 years.Decide the pumping frequency based on the solids or use the table below as a guide. >>More frequent pumping is needed if garbage disposal is used. These numbers assume full time residence.

Tank Pumping Frequency in Years

Tank Size (gallons)

Number of People in the Household

1 2 3 4 5 6
500 6 3 2 1 1 0.5
750 9 4 3 2 1 1
1,000 12 6 4 3 2 1.5
1,500 19 9 6 4 3 3
2,000 25 12 8 6 4 4