HOW DO SEPTIC SYSTEMS WORK?
A septic system uses natural processes to treat and dispose of the wastewater
generated in your home. It typically consists of a septic tank and a
drainfiled, or soil absorption field. The septic tank provides the first step
in treatment. As wastewater flows into the tank, the heavier solids settle to
the bottom to form a sludge layer, and the lighter solids, greases, and oils
float to the top to form a scum layer. The liquid wastewater (effluent) from
the tank flows into gravel-filled trenches in a typical drainfield where it is
distibuted via perforated pipes and then treated by the natural soil system.
The septic tank provides some biological treatment of the sludge and scum
layers that accumulate there. The majority of treatment occurs in the
drainfield where the effluent enters the soil and is treated as it percolates
to the groundwater. The soil acts as a biological and physical filter to remove
harmful substances, Including disease-causing bacteria and viruses, toxic
organics and other undesirable wastewater constituents remaining in the
Outlet filters or baffles are located in the tank and are designed to prevent
the sludge and scum from flowing into the drainfiled. if the tank is not pumped
regularly to remove the accumulated solids, The tank will fill with sludge and
the solids will be washed out into the drainfield, or clog the outlet filter.
If the solids reach the drainfiled or clog the outlet filter, they will quickly
clog the soil and eventually lead to system failure.