Rural sewage treatment
Essentially this is the same procedure as within a municipal
district. The one major difference being that there is no 'make-it-all-ok' treatment
plant. We are in the hands of nature and we have to be sensitive to the natural
phenomena or things can go horribly wrong (i.e. the simple systems fail, and we’re
quite literally in the pooh!).
The three types of rural sewage systems
- Pit latrines or long drop toilets, which are just holes dug in the ground with a privacy shed.
- Septic tanks with their soakaway drain or leach field - rudimentary, time-tested, usually single-house 'sewage plants'.
plants compact treatment works, which may serve one large home or country
lodge up to a cluster of neighbouring residences or public facilities.
The Pit latrine or 'long drop' is probably the most numerous group of toilet type worldwide. Usually found in sub-economic, primitive or socially disadvantaged communities, it is essentially what its name implies: a hole in the ground. A pit toilet will last until it fills. This is infinitely variable and a factor of size combined with frequency of usage. Diet also pays its part, the higher the 'fibre' the quicker it fills. Read more on Pit latrines.
Septic tanks are believed to be invented over 150 years ago in France when peasants flocked together swelling townships at the commencement of the Industrial Revolution. Septic tanks consist of two separate parts:
- A pair of in-ground digestion tanks that receive and break down water-borne faecal material from the dwelling;
- A soakaway (French drain, seepage drain or leach field) where the transporting water containing dissolved/emulsified COD is progressively 'cleaned' and 'polished' by slowly soaking over a wide surface area into the surrounding soil.
Sewage treatment package plantsThese are relatively new innovations, replacing the soakaways in sensitive or crowded areas. Generally additions to the 'biodigesting' septic tanks, they can be designed to produce final effluent of good (re-usable) quality. Learn more about Sewage treatment package plants.
Managing rural sewage
There are DWAF regulations regarding the proximity of sewage disposal systems to natural water courses. As a general rule, there must be at least 100m from the discharge point (your soakaway, for example) to the centre of the water course/river in upper/inland catchment areas. The soakaway must also be above the highest flood line recorded in the last 50 years.
An existing septic tank may be granted special dispensation. But if it is a new construction, it may be necessary to catch the sewage in a small wet-well and pump it back to a point where a tank and/or soakaway can be placed outside the influence of the water course. If in doubt ask your local catchment manager as the goal posts are often moved.
BIO-SYSTEMS products that aid rural sewage disposal include:
We supply drawings for both septic tanks and soakaways and
can advise on the sizes necessary if you let us know the number of residents
and the soil type. There is a small fee for this, usually around R250 + Vat for
the full package, which we can send to you via email. For more details and
publications on septic systems please ask us on firstname.lastname@example.org.
Rural sewage disposal