System Components
A typical household sewage treatment system consists of a house sewer, septic
tank, distribution box and absorption field or seepage pit. All of this
information may or may not apply to the system at your home.
House Sewer - The pipeline connecting the house and drain to the septic
tank.
Septic Tank - Untreated liquid household wastes (sewage) will quickly
clog your absorption field if not properly treated. The septic tank provides
this needed treatment. When sewage enters the septic tank, the heavy solids
settle to the bottom of the tank; the lighter solids, fats and greases partially
decompose and rise to the surface and form a layer of scum. The solids that have
settled to the bottom are attacked by bacteria and form sludge. Septic tanks do
not remove bacteria and, therefore, what is discharged cannot be considered safe
to drink or handle.
Distribution Box - Serves to distribute the flow of liquid effluent from
the septic tank evenly to the absorption field or seepage pits. It is important
that each trench or pit receive an equal amount of flow. This prevents
overloading of one part of the system.
Absorption Field - A system of narrow trenches typically filled with a
bed of washed gravel or crushed stone into which perforated or open joint pipe
is placed. The discharge from the septic tank is distributed through these pipes
into the trenches and surrounding soil. The subsurface absorption field must be
properly sized and constructed to assure satisfactory operation and a long life.
Seepage Pit - A covered pit with a perforated or open-jointed lining
through which the discharge from the septic tank infiltrates into the
surrounding soil. It is generally installed in sandy or gravel-type soils. Like
the absorption field, the seepage pit also must be properly sized and
constructed. While seepage pits normally require less land area to install, they
should be used only where absorption fields are not suitable and well water
supplies are not endangered.
In most rural areas and in many suburban residential areas, individual household
sewage treatment systems are relied upon for the disposal of household wastes.
Wherever possible, sewage should be collected in community sewers connected to a
central treatment plant.
A household sewage treatment system will serve a home satisfactorily only if it
is properly located, designed, constructed and maintained. The purpose of this
brochure is to explain how your system works and how it should be operated and
maintained.
Operation and Maintenance
• The contents of the septic tank should be pumped every two to three years or
so; especially when the total depth of sludge and scum exceeds one-third of the
liquid depth of the tank. If the tank is not cleaned periodically, the solids
are carried into the absorption field; rapid clogging occurs; premature failure
follows; and finally, the absorption field must be replaced. Pumping your septic
tank is less expensive than replacing your absorption field.
• Detergents, kitchen wastes, laundry wastes and household chemicals in normal
amounts do not affect the proper operation of household sewage treatment
systems. However, excessive quantities can be harmful.
• Avoid the disposal of cigarette butts, disposable diapers, sanitary napkins,
plastics, trash, etc., into your household sewage system. These items are not
readily decomposed.
• Septic tank additives are not recommended. Additives are unnecessary to the
proper operation of household systems and may cause the sludge and scum in the
septic tank to be discharged into the absorption field, resulting in premature
failure. Some additives may actually pollute groundwater.
• Garbage grinders substantially increase the accumulation of solids in the
septic tank, as well as the solids entering the absorption fields and pits.
Their disadvantages outweigh the convenience they provide and are not
recommended for households with their own sewage treatment systems. If used, the
septic tank size should be increased. Most raw vegetables will not break down
completely, so accumulate more solids
within the septic tank — leading to more frequent pumping requirements OR
premature failure!
• Connecting your laundry wastes to a separate waste system (dry well or seepage
pit), while not normally necessary, will reduce the load on the regular system
and permit the survival of a marginal system.
• All roof, cellar and footing drainage, and surface water must be excluded from
the system. This drainage water can be discharged to the ground surface without
treatment; make sure it drains away from your sewage treatment system.
• Roof downspouts should not drain toward the absorption field.
• Backwash from water softeners and/or iron/manganese removal equipment may be
discharged to the septic tank and absorption system without damage or to a
separate system.
• Chemotherapy will normally kill ALL bacteria within the system, if anyone in
household undergoes that therapy check with your pumping company for suggestions
to preserve proper operation of septic system
• Roots from trees in the immediate area of the absorption lines may clog the
system.
• Keep swimming pools (above or in-ground) away from the absorption field.
• Check with your local septic system pumper to determine if periodic
maintenance had been performed! If not, we suggest pumping when you first take
possession of the home and start regular, periodic pumping
Septic Systems need regular maintenance (pumping) to function
properly.
The typical 1000-gallon size tank should be pumped according to household size:
3 people = 3.7 years / 4 people = 2.6 years / 5 people = 2 years -- Varies with size
of tank and # of occupants
Check with local pumping company to get their recommendations for your size tank
& system
Most raw vegetables will not break down completely, so accumulate more solids
within the septic tank — leading to more frequent pumping requirements OR
premature failure!
Caution
• Avoid entering your septic tank.
• Individuals have died from gas asphyxiation.
• Never permit heavy equipment to pass over the absorption field.
• Conserve your water usage; this can prolong the life of your sewage treatment
system. Check defective toilet tank valves, repair leaky fixtures, install
appliances and fixtures that use less water and always avoid wasteful practices.
• Your sewage treatment system is normally designed to accommodate two persons
per bedroom. If your household is larger than this, or if you add additional
bedrooms, enlarge the system.
• If surface water from higher ground is flowing onto your absorption field,
install a ditch or berm to intercept this surface water.
For more detailed information concerning special conditions in your area,
contact your local health department, or call 1-800-458-1158.