Taking Care Of Your Septic System PDF Print E-mail
Written by Greg Wayman   
Monday, 04 October 2010 11:59
How Septic Systems Work
by GregWayman


How Septic Systems Work

Septic systems consist of 2 main components: the septic tank and the absorption field. Before we jump into the maintenance tips, we need to cover how the system works. When you dishwasher drains, your washer empties, the water softener discharges the brine, you flush your toilets, or run your sinks, the solid and liquid waste run down your sewer line and dump into the septic tank. On average, each person uses about 100 gallons of water per day. As the solids enter the tank, they will settle to the bottom where anaerobic bacteria break it down. That bacteria is naturally found in the solids of human waste. The liquids will flow across the top of the tank and drain out through the laterals into the absorption field. The laterals have aerobic bacteria that help clean the liquids. If the bacteria is kept at equilibrium constantly breaking down the solids and liquids, then the tank should be almost self-sufficient. Septic systems should last a long time if properly maintained.

The Location of Your Septic System

Here are some general rules for the proper location of your septic system: minimum 15' from the foundation, minimum 10' from surface water, minimum 10' from property lines, and minimum 50' from your well. The absorption field must be a minimum 50' from surface water, minimum 100' from your well, minimum 30' from the foundation. The absorption field consists of a trench that is typically 4'-5' deep by 100' long.

Sizing Your Tank

To make sure your septic tank is sized properly, the general rule of thumb is a 1,000 gallon tank matches up to a 2 bedroom or smaller home while a 1,500 gallon tank matches up to a 3 bedroom home.

Don't Put This Stuff Down The Drain

Garbage disposals are a septic system's enemy. What will go down a disposal doesn't mean it should. Avoid starches and stringy greens. They float and will clog your laterals. Use common sense here. Plastics, diapers, condoms, etc. should NOT go down the drain. Chemical cleaning products that aren't labeled 'septic safe' shouldn't be dumped down the drains either. The natural anaerobic bacteria in your tank can be adversely affected causing sludge and solids to build up faster, in turn, clogging your laterals. When choosing your toilet paper, look for the 'septic safe' label. If the toilet paper takes too long to biodegrade, it too can clog the laterals.

Maintaining Your Absorption Field

In the summer, the absorption field evaporates approximately 60% of the water off. This is why it's crucial to never impede the field's surface drainage. Do not pour concrete or asphalt over the absorption field. Do not plant trees or shrubs in the absorption field as their roots can clog the laterals. Do not drive your truck, car, or heavy equipment over the field as this can crush or break the laterals. You also want to limit the volume of water discharging into the tank at any given time. If you have too much water discharging into your septic system too fast, this hydraulic overload can lead to solids and sludge churning, in turn, clogging your laterals also. Space your laundry out and turn your water softener off if you have one. When the water softener is discharging the brine, it dumps a large volume of water into the septic tank which can lead to issues.

Pumping Out The Septic Tank

A septic tank should regularly be pumped as solids and/or sludge will accumulate. The general rule of thumb is to have your tank pumped every 2-5 years. If you have a large family, you'll want to pump your tank more frequently. If you wait too long, the solids or sludge can buildup and cause your laterals to be clogged. When this happens, your absorption field will need to be dug up and a new one installed.

Having Your Septic Inspected

In Nebraska and Iowa, you need to be state licensed to perform a septic inspection. When you hire a state licensed contractor to conduct the inspection, they should check the water level in the tank, then push 100 gallons of water into the tank and monitor the tank level. If the water level rises, then that is an indicator of a clogged or partially clogged lateral. They should judge the thickness of the sludge, inspect the sidewalls for cracks, check the condition of the inlet and outlet baffle, check the condition of the access port, and use a 'T'-bar to probe the laterals. If the 'T'-bar finds moisture, that's an indicator that the absorption field is partially saturated. The 'T'-bar is also used to determine the size of the septic tank.

Many thanks to Jim Sandvold of S&S Pumping out of Blair, Nebraska for attending our home inspector chapter meeting and sharing his knowledge. His company performs septic inspections, pumps the tanks, and installs them also in the Blair and Omaha area.

DISCLAIMER: This article is provided as information only and is not to be taken as financial advice.

To learn more about maintaining your home properly, visit our website atOmaha-Home-Inspection.com. Also published at Taking Care Of Your Septic System.