Private Sewage Disposal Systems Flashcards
the final stage of the plumbing process;
where used water and water-carried wastes are brought to various disposal outlets
Disposal Phase
A watertight covered receptacle designed and constructed to receive the discharge of sewage from a building sewer, separate solids from the liquid, digest organic matter and store digested solids through a period of detention, and allow the clarified liquids to discharge for final disposal
Septic Tanks
solid organic matter that are denser than water
and settle at the bottom of the septic tank
Sludge
lighter organic material that rise to the surface of
the water
Scum
liquid content of sewage
Effluent
Bacteria in septic tank to encourage decomposition; relies on oxygen to survive
Aerobic bacteria
Bacteria in septic tank to encourage decomposition; can survive in places without oxygen
Anaerobic bacteria
minimum dimensions of a septic tank
L= 1500mm
W=900mm
D=1200mm
3 degrees or grades of waste water
Grey Water (or Area Water), Black Water, Storm Water
2 TYPES OF SANITARY SEWERS
Tributary Sewers, Intercepting Sewers
CLASSIFICATION OF SEWERS
Combination Public Sewers, Storm Sewers, Sanitary Sewers
Termination points of individual units or structures Usually round shaped, with diameters between 0.60 to 1.2 meters Made of vitrified clay or cement pipes; often installed by the curb line, before the street sewers Normally laid in the Northern or Eastern side of streets with east-west or north-south orientations
Tributary Sewers
a.k.a. ‘collecting sewers’ Termination points of tributary sewers Placed much lower in the ground, from 4 to 30 meters in depth Varies in shape but have a diameter or effective opening ranging from 0.60 to 3 meters Sloped at an angle of 1:50 or 2% Lifting stations are placed at certain intervals and pumps or sewage ejectors are used to lift the waste; sewers terminate at the disposal plant
Intercepting Sewers
Private sewage disposal system common in rural areas for structures with large adjacent open fields
DISPOSAL FIELDS
a loosely lined excavation in the ground, which receives the discharge of a septic tank; designed to permit effluent to seep through pit bottom and sides
SEEPAGE PITS