A septic tank system is required if the building (with a plumbing facilities) is not on a city sewer system, than in most cases it has a septic tank system to dispose of the waste water. an on site wastewater disposal system avoids the spread of disease by preventing human sewage from contaminating the ground surface, well water supplies and streams.  The tank is primary horizontal continuous flow type of sedimentation tank having extra provision to digestion of settled sludge.

 
 

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