How Septic Tanks Work: The Ins and Outs of the Septic Tank System


How Septic Tanks Work: The Ins and Outs of the Septic Tank System

Understanding how septic tanks work is especially important when living in a home with a septic system. Whether the septic system is new or has been in use for a while, things can happen that cause the system to not work properly.

History of Septic Tanks

The design is credited to John Mouras in the mid 1800s with a patent issued for the system around 1881. The patented septic tank system was brought to the United States in the late 1800s. The basic principle of the septic system is much the same as when Mouras first built a prototype for his home.

How Septic Tanks Work

Although the septic tank system is simplistic in its design, it functions at a high level of efficiency. Any time the washing machine, shower, or bathtub is used, the kitchen or bathroom sinks drain, or the toilet is flushed, the water and the waste exit the house through piping.

With a septic tank, both water and waste are directed into the septic tank. If you could see inside the tank, it would show some of the waste sinking to the bottom of the tank while some would be floating.

The waste, which can be from the toilet, hair, soap, and shampoo gunk from the shower drain, and bits and pieces of food from the kitchen drain, can settle to the bottom and deteriorate into what is called “sludge.”

The water accumulating above the sludge is called “effluent.” As water from the home continues to make its way into the septic tank, an equal amount of effluent is directed out of the tank and into the drainfield where it runs through a series of perforated pipes and gravel layers eventually melding into the ground (drainfield.)

In an effort to help prevent the gunk and sludge resting on the bottom being stirred up by incoming water and making its way into the drainfield, a baffle was added to the design.

When incoming water from the home causes outgoing water to be flushed out, it goes into a baffle, or what looks like an additional holding tank. If any sludge from the main tank makes its way through the outlet, chances are, the majority of the gunk will remain inside the baffle versus going into the drainfield.

Things That Can Become an Issue

  • The number of people in the home and the amount of water usage can become problematic
  • Doing multiple loads of laundry can cause the system to back up
  • Excessive rain can flood the drainfield
  • Outlets in the tank are clogged or perforated pipes in the drainfield are collapsed or clogged
  • The soil in the drainfield needs replacing
  • In time, lint particles from the washing machine filter clog the drainfield
  • The septic tank is overdue for maintenance and needs pumping out

For answers to your questions, contact the Pink Plumber today.

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