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Septic System Layout

Septic System: Domestic; Typical 

The diagram [below] shows the typical layout of a domestic Septic System; such as you would find in a farm, weekend cottage, or house in the country [outside an urban municilality].


The entire system works on gravSeptic Tank Schematicity [sewer ‘fall’ should be between 1:50 and 1:90]. It is cheap with no input of costly ‘energy’


It matters not how many bathrooms or loos, but it DOES matter how many residents [including staff] use the system. Upon these numbers, and the type of soil, the size of the septic tank and soakaway depend; and can be calculated.


It is good practice to size the [masonry] septic tank  at 1,000lt per resident + 20% for overnight guests and visiting friends .  Rather add 1,000lt capacity for families with teenage children. [regular ‘sleep-overs’].      Be ‘Green’


The only waste water entering the tank, should be from the kitchen: and that must go via a grease trap/gulley, [ we can advise], to protect the tank from the refined fats used in modern foodstuffs. It may be ‘heart &‘cholesterol friendly’ but that is because the natural bacteria in our digestive system are unable to degrade it: and that goes for the tank as well !. If ‘grey waste water [shower, bath & laundry] go to the tank, they will cause ‘hydraulic overload’ because the ‘bugs’ need 18 – 21 days to degrade the sewage they feed on, [scientific fact] otherwise the partially degraded ‘fats’ will spill over to the soakaway, and seal the minute gaps between the soil particles.


The tank ‘backs-up’, and overflows. You call the honey sucker, but all it does is remove the water [and the microbes]. The cloying fat remains, and the tank overflows again.


Each section of sewer [PVC 110mm pipe] should be in a straight line, with an inspection chamber at each turn.  Chambers should be a minimum of 30 m apart to facilitate rodding if a blockage occurs. If the sewer [or tank] leaks, it will attract tree roots which will, overtime, cause expensive trouble.


We design sized brick septic systems, for R285.00 incl Vat in email format. We must know:

1.    How many residents

2.    Soil type and Percolation Co-efficient [permeability of the soil – sandy loam is best]

3.    Municipal district: [regulations re distances of components vary]


Septic systems are the ideal rural digestor. There are thousands of homes in the world served by them, trouble free !  If the soil is unsuited to soakaways, we offer another plan !

Plastic tanks are not a good idea, they are usually the wrong shape, and far too small


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