urban and suburban areas, there are sewers to carry household waste to
municipal wastewater treatment plants. But in rural areas, the functions
of sewers and treatment plants are fulfilled by each residence's own septic
household drainage waste is disposed of through the septic system. The
quantity and composition of waste generated in the home varies according
to the number of residents, their personal water usage and the water-using
appliances in the home.
septic system is actually a small, on-site sewage treatment and disposal
system buried in the ground. The system is comprised of two parts: The
septic tank and the sail absorption area.
modern septic tank is a watertight box divided into two compartments and
usually made of precast concrete, concrete blocks or plastic. When household
waste drains into the box, several things take place.
- Organic solid material floats to the surface and forms a layer called
the "crust". Bacteria in the septic tank biologically convert this material
- Inorganic or inert solid materials and the by-products of the bacterial
digestion sink to the bottom of the tank and form a layer called "sludge".
Only fairly clear water should exist between the crust and sludge layers.
This clear water - and only this clear water - should overflow into
the second compartment and then out to the soil absorption area.
Septic Tank Bacteria
Septic Tank Bacteria must be present in the septic tank to digest the
organic solids. Normal household waste provides enough bacteria to keep
the digestive process working properly. A faulty system is the result
of solid material overflowing into the second compartment. It is the solids
overflow that clogs soil pores and causes septic systems to fail. Two
main factors cause solid material to build up to the point of overflow:
Lack of Pumping
Soil Absorption Area
field beds generally consist of a network of perforated pipes running
through layers of sand and crushed stone. They may be constructed above
or below ground. If solids are allowed to clog the pipe perforations or
the sand, drainage will begin to slow and eventually stop.
system maintenance means two simple things. First, sludge that accumulates
in the bottom of the tank must be pumped out at regular intervals. How
frequently your tank must be pumped depends on the size of the tank, the
use it gets and the condition of the system. There is no additive you
can put in the tank to get rid of the sludge.
A Septic System Must Be Pumped Out
the sludge in your system is not removed, it will eventually overflow into the second compartment.
This will clog the system and it will need to be replaced, at enormous
expense and inconvenience.
second part of septic system maintenance involves the bacteria necessary
for solids digestion. If bacteria-killing products - such as bleach, disinfectants,
drain openers, detergents, etc. - are used in the home, the bacteria must
be replenished, in order to avoid the disastrous build-up and overflow
Your septic tank could be overflowing solid material into the soil right
now, and you won't know until it blocks the soil so badly that no more
drainage is possible. This blockage takes varying periods of time depending
on soil structure. But these are the facts: a neglected system will get
blocked; it will overflow; it will have an obnoxious odour; it will contaminate
and pollute the surrounding area. It will probably have to be replaced.
The first septic system emergency usually marks the beginning of the end.