WHAT IS A SEPTIC TANK SYSTEM?
- A septic system consists of your plumbing fixtures and pipes in your house,
the sewer service lines running into your septic tank, an air vent, a
septic tank with an outlet discharging wastes into an effluent soil absorption
drain field.
- A maintenance program is the key to extending the life of your septic
system and preventing damage to your property, which can be very costly
when trouble occurs.
- It is recommended that the tank be cleaned (pumped) through the manhole
(removing all solids) every 1 to 3 years depending on the number of people
in the home, size of the tank and use of a garbage disposal.
WARNING SIGNS OF A CONTAMINATED TANK
- Sluggish drains
- Plumbing backup in your bathroom and kitchen
- Awful odor in your drains or yard
- Mushy ground or greener grass in septic tank area Your system should be
pumped out every 1 to 3 years. This will help you avoid the disasters
that will and do occur.
HOW THE TANK WORKS: The contents of the septic tank separate into three
layers:
- Floating scum layer - soaps, greases, toilet paper, etc.
- Liquid layer - water, liquid, and suspended solids.
- Sludge - heavy organic and inorganic materials at the bottom of the tank.
Naturally occurring bacteria in the sewage begin to break down organic materials
in the tank. This is often referred to as primary treatment. Pathogens (biological
agents that can cause disease) in the waste are NOT destroyed in the septic tank.
Bacteria in the septic tank prepare the wastewater for final treatment in the
drain field.
The septic tank is the first step of the wastewater treatment process. The septic
tank is a solid tank designed specifically to accept all wastewater from the home.
Some installations may have two tanks in a row or one large tank with two compartments.
The INLET BAFFLE forces wastewater entering the tank to be mixed with the
liquid contents to begin bacterial breakdown of organic materials and separation
of solids. The inlet baffle also prevents the floating scum layer from floating
back and clogging the inlet pipe.
The OUTLET BAFFLE prevents scum from leaving the tank. If the scum layer
reaches the outlet pipe, the pipe will become plugged. Scum in the drain field
will clog soil pores and destroy its ability to treat wastewater. Filtering devices
can be installed at the outlet of new or existing tanks to prevent solids from
reaching the drain field. Regular maintenance is required to keep the filters
from clogging and causing backups. Filters are not a substitute for proper operating
or maintenance practices!
INSPECTION ACCESS, pipes of 4- or 6-inch PVC (plastic) material should
be located above the inlet and outlet baffles to allow for inspection of pipes
and baffles. Clogs in the inlet or outlet pipes can be unplugged through the inspection
pipes. When operating properly, the septic tank is always "full" to the level
of the bottom of the outlet pipe. Inspection pipes must always be capped. They
may be cut off flush with the ground to ease lawn care; however, the pipes should
be left "long" until the final grade on a new site is determined.
The MANHOLE is the large entrance (20"-24") through which allows proper
cleaning and inspection of the tank. The manhole is often buried below ground
level. It may be raised from the cover of the tank with concrete or plastic rings
for easier access. It is usually located in the center of the tank; however, some
manufacturers locate it closer to the inlet end of the tank. There may be more
than one manhole, in which case they are usually located at the ends of the tank.
The manufacturer or installer may be able to tell you where it is.
The following suggestions are designed to increase the useful life of your septic
system. Their effectiveness will vary depending on the age and condition of your
septic system.
A. Minimize the Liquid Load - The less wastewater you produce, the less
the soil will have to absorb. Water conservation is the cheapest and easiest way
to protect your septic system. Remember, the gallonage of the septic tank must
not be exceeded in any one day. This can be achieved by:
- Repairing leaky fixtures.
- Washing clothes only when you have a full load. Avoid doing several loads
in one day. The septic system design includes the average use of the clothes
washer (definition of average use--three to four loads per week).
- Take short showers instead of baths. Don't turn the shower on all the
way and turn off the water while lathering. Install a water-saving device
in the shower system.
- Use a water-saving device in your toilet tank and don't flush unnecessarily.
- Don't let water run while washing teeth, hands, vegetables, dishes, etc.
Use a stoppered basin.
- Many other ways of conserving water exist. Use water-saving devices where
feasible. Be alert and institute other water-saving ideas.
B. Minimize the Solids Load - Do not use your septic system for anything
that can be disposed of some other way. The less material you put into your septic
tank, the better the quality of the effluent going to the leaching system.
- Minimize or avoid using the garbage disposal unit. Remove scraps with
the garbage or properly compost them.
- Collect grease in a container near the sink rather than pouring it down
the drain.
- Minimize the discharge of paper products. Non-degradable items, such as
disposable diapers, sanitary napkins, Kleenex, kitty litter and paper
towels are especially harmful. Use a good quality approved toilet tissue
that breaks up easily when wet.
- Basically three products should go into the septic tank: human wastes,
toilet paper, and water from toilets, bathing fixtures, kitchen sinks
and laundry washers.
- Ordinary use of household chemicals will not affect the bacteria in your
system if not used in excessive amounts. Do not use your tank to get rid
of oils, paints, insecticides or other poisonous liquids.
C. Additional Means to Protect the Installed Septic System
- Do not plant large trees over the absorption system. Small feeder roots
will enter the drain holes of the leachfield drain lines and form a mat
within the drain line. This mat blocks the flow in the level drain line
rendering the remainder of the line unusable. Large roots may displace
the drain line. As a general rule, large trees must be as distant as possible
from any trenches. Trees with a trunk diameter of nine inches should be
at least ten feet distance from any trenches.
- Ideally the leach line/bed systems should be left in uncovered open sunny
areas so as to be provided maximum evaporation. This is an important factor
in these systems, but not applicable to seepage pits or dry wells.
- Do not allow rainwater or drainage water to pond over the leach field.
Maximum saturation and temporary failure may occur until the ponding dissipates.
- Do not construct walkways, patios, swimming pools, permanent structures
or parking lots, over or within the leach line/bed areas. This would prevent
maximum evaporation, may cause damage to the system and may cause a premature
failure.
- Keep vehicles off your leach line/bed system; driving over them repeatedly
can damage underground pipes and soil porosity.
- Before purchasing a house, you should request a "Septic Certification".
- Your tank should be routinely pumped at least every three years or once
a year if a commercial establishment.
For more information:
University of Minnesota Extension Services:
