Printable PDF About Septic Systems

What is a Septic System:

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Households that are not served by public sewers usually depend on septic systems to treat and dispose of wastewater. There are many different types of septic systems that fit a wide range of soil and site conditions. In our area the most common type of system is a gravity fed system. If your drain field happens to be up hill you may need a "pump assist" system.

A Typical Septic System has Three Main Parts:

The Septic Tank — A septic tank's purpose is to separate solids from the wastewater, store and partially decompose as much solid material as possible, while allowing the liquid (or effluent) to go to the drainfield. A typical home will have a 1000 gallon tank.
The Drainfield — After solids settle in the septic tank and as decomposition continues, the liquid wastewater (or effluent) is discharged to the drainfield, also known as an absorption or leach field.
The Soil — The soil below the drainfield provides the final treatment and disposal of the septic tank effluent. After the wastewater has passed into the soil, organisms in the soil treat the effluent before it percolates downward and outward, eventually entering ground or surface water. The type of soil also impacts the effectiveness of the drainfield; for instance, clay soils may be too tight to allow much wastewater to pass through and gravelly soil may be too coarse to provide much treatment.

Why Septic Systems Fail:

A failing system can become a source of pollution and public health concern, causing property damage, ground (well water) and surface water pollution and disease. Once your septic system fails to operate effectively, you may need to replace it, costing you thousands of dollars. Therefore, it makes good sense to understand and care for your septic system.
Your daily habits can greatly affect your septic systems performance. Using more water than the system was designed to handle can cause a failure. Disposal of chemical or excess organic matter, such as that from a garbage disposal, can destroy a septic system. Cloths soaps, softeners and bleaches can kill the bacteria which contribute the biological actions which cause proper decomposition. Lint from cloths do not settle in septic tanks and over time can clog the leach field. Modern materials such as polyesters do not decompose as cottons and wools do.
If the liquid effluent cannot soak into the soil surrounding the leach field, sewage may back up into the system and overflow into the house or puddle on the surface of the ground. There are several possible causes for this problem.

1. Poor Soil Conditions and Septic System; Faulty Design or Installation of Septic Systems. A leaching system placed in unsuitable soil, a system that is too small for the house it serves, or an improperly constructed system may lead to early failure.
2. Soil Clogging and Septic System; If sludge or scum is allowed to escape into the distribution box and from there into the leach field, the soil will quickly become clogged. If this happens, the liquid will no longer soak, or percolate, into the soil. This condition can be caused by broken baffles in the septic tank that allow sludge or scum to escape. Failure to have the tank pumped can also lead to a situation where the sludge and scum overwhelm the baffles.
3. High Water Table and Septic System; During abnormally wet seasons groundwater may rise into the leach field and force sewage upward to the ground surface. This condition may mean the system has to be re-installed at a higher level. It may also be possible to intercept the high groundwater with a series of drains around the system called "curtain drains".
4. Roots and Clogging of Septic System; The roots of trees and bushes planted too close to the system can sometimes enter and block the pipes of the system. Removal of the plants and clearing the pipes of the roots is usually required.
5. Physical Damage to Septic System; Trucks or heavy equipment passing over the system can damage pipes and joints to the point of rendering the system inoperable. You should be aware of the location of the system and direct traffic to avoid such damage.

Maintaining Your System

The following maintenance tips can help your system provide long-term, effective treatment of household waste.
1. Inspect and Pump Frequently; The most important step to maintaining your septic tank is to remove sludge and scum build-up before it washes into the drainfield. How often your tank needs pumping depends on the size of the tank, the number of people in your household, the volume of water used, and amount of solids (from humans, garbage disposals, and any other wastes) entering the system. Generally, tanks should be pumped every 3 to 5 years.
2. Use Water Efficiently; Excessive water is a major cause of system failure. The soil under the septic system must absorb all of the water used in the home. Too much water from laundry, dishwasher, toilets, baths, and showers may not allow enough time for sludge and scum to separate. The less water used, the less water entering the septic system, resulting in less risk of system failure.
3. Minimize Solid Waste Disposal; What goes down the drain can have a major impact on your septic system. Many materials do not decompose and consequently, build up in your septic tank. If you can dispose of it in some other way, do so, rather than putting it into your system.
4. Keep Chemicals Out of Your System; Keep household chemicals out of your septic system, such as caustic drain openers, paints, pesticides, photographic chemicals, brake fluid, gasoline, and motor oil. Improper disposal of toxic chemicals down the drain is harmful to the environment, as well as the bacteria needed to break down wastes in the septic system.
5. Septic System Additives; Adding a stimulator or an enhancer to a septic tank to help it function or "to restore bacterial balance" is not necessary. The naturally occurring bacteria needed for the septic system to work are already present in human feces.

Signs of Failure

Septic systems are designed to provide long-term, effective treatment of household waste when operated and maintained properly. However, most systems that fail prematurely are due to improper maintenance. Following are signs that your system need attention.
1. Odors, surfacing sewage, wet spots, or lush vegetation growth in the drainfield area.
2. Plumbing or septic tank backups (often a black liquid with a disagreeable odor).
3. Slow draining fixtures.
4. Gurgling sounds in the plumbing system.
5. If you have a well and tests show the presence of coliform (bacteria) or nitrates, your drainfield may be failing.
6. Lush green grass over the drainfield, even during dry weather.

What About Pump Stations?

If your leach field is uphill from your home or if your have a pressurized sewer system you will have a Pump Tank. If you have a pump tank that is part of your septic system, understand that this is the only way the wastewater gets to the drainfield. As long as your septic system is properly maintained, your drainfield should last a long time. Improper maintenance (not pumping the septic tank) will allow the sludge to collect in the pump tank affecting the pumps operation, and sooner or later the sludge will end up being pumped into the drainfield. This pump will soon fail because it was not made to pump sludge. Spend a little more money and have your pump tank cleaned out when you pump your septic tank.If your pump tank does not have a ground level access port you may want to consider having one installed for service and occasional inspections.

Fore more information check:

Septic System Basics:
http://www.co.thurston.wa.us/health/ehoss/septic_basics.html

Maintaining your Septic System:
http://www.nesc.wvu.edu/pdf/ww/septic/pl_fall04.pdf

Environmental Protection Agency:
https://www.epa.gov/septic