Septic Tanks : The Last Days of Latrine Toilets

Solid and liquid waste disposal is a major challenge that we face today in most of our town and cities. We see rubbish all over, dumpsites within residential and commercial zones, noise pollution from all the “matatus” at the bus-stations etc., but the most challenging one is the sewerage disposal. People often say that the best invention that helped promote hygiene and improve human life, is actually the water-closet (WC). The arising need of a WC is a source of water, storage of that water and a space for disposing off the refuse. However, the only problem with it is that it only managed to travel half-way round the world.

As a young person, we used to play and walk along the main sewer line in town. It was about 3 to 4 feet in diameter, made of cast-iron, bolted at the ends with gasket. We walked on top till the next manhole, and followed it all the way to the then defunct sewer treatment plan, right there at the Kisumu Sewerage Waste Recycling Center. God forgive our innocence. I am told that not much has changed really.

In retrospect, the sewer line marked the end of the post-colonial planned town on one side and another world of civilization on the other. Unfortunately, this scenario is replicated all over the country, with distinct demarcating of municipal sewerage network system abruptly ending, and leaving other forms of civilization settlements at their own disposal. A civilization that sometimes hardly know nothing about piped water or WC, but predominately uses latrines as their main waste management system. But not anymore, because these are the last days of the latrine toilets. We are in the closing hour of the latrines era.

SEPTIC TANKS: Getting Started with Waste Management


Septic Tanks (ST) are essentially holding chambers for waste awaiting further processing and final disposal. Waste from buildings is either classified as black or grey: Black meaning toilet waste and grey all other waste. For the kitchen sink waste, it’s important to install a grease or cooking oil trap because grease interferes with the decomposition process of waste matter in the septic tank. The components of a ST include a holding unit, a distribution box, and leaching field or cesspool.


ST come in a variety of types and classification or categories. The major classification system of ST is the means or methods by which waste is decomposed in the tank. There are aerobic and non-aerobic ST. In non-aerobic tanks, bacteria breakdown the fecal matter in the absence of oxygen, and most of our existing ST are of non-aerobic type. For the aerobic type, an aeration component is added to introduce oxygen into the tank and help bacteria further decompose the matter in the presence of oxygen. An example of an aerobic type of ST in Kenya is the famous Bio-Digester.

Size Determination:

ST are determined by either the number of occupants or bedrooms in a building. By calculating and assigning a value to an occupant or a bedroom, the size of the ST is determined by considering the depth you intend it to be and the width you want, then only the length becomes the only variable.

Challenges of Septic Tanks (ST):

  1. Land requirement for ST, distribution field or cesspool
  2. The soil percolation rate
  3. How to dispose of the solid waste matter
  4. What to do with the liquid matter

Fortunately, innovation and advancement in sewerage waste management have produced many solutions that try to overcome these challenges.

WASTE MANAGEMENT BUSINESS: Getting Started in AEC in Kenya

Money has become an incentive to many people, and this makes it very easy to solve many of the problems we experience on day to day basis. In so doing, we shall say that “waste is money.” Surely, I am not crazy.

There are well established waste management businesses around the world and this is a living proof that indeed, waste is money, good and clean money. The genius, therefore, of solving a problem, is to make it an opportunity for people to exploit. And these is how we should try to run a waste management industry:

a) Education and Awareness:

Create a Septic Tank Institute or University to create, preserve, research and promote the best practices in and effective methods of handling waste in an environmentally responsible manner and create public awareness and also for all the stakeholders involved.

b) Organization

Identify business organization structures or formation and procedures for all sizes from small to large. For example, a small company (3 to 5 employees) can service 50-100 homes annually, a medium company (10-20 employees) can service 100 to 500 homes and a large company (25 to 50 employees) to serve over 500 homes annually. This will enable people to participate at different levels from the village to community level and even town to city level.

c) Products and Services

Set business products and services that are deliverable as chargeable or billed items. For example, services can be offered as Septic Tank Design and Planning and a product such as Septic Tank Construction and Installation. In so doing, assign relevant market values, that offer good rate of return, say 50,000/= per service etc.

d) Warranty and Renewal Services

Develop a warranty program that will mandate the septic tank or bio-digester to be at least inspected after 6 months or three times a year and assign a market value to the warranty service, say 10,000/= or 20,000/= depending on the size of the system and prevailing market conditions. Items included in the warranty may include, but not limited to, solid waste disposal, liquid waste inspection, maintenance and monitoring, servicing and repair, and so on.

With proper analysis and organization, a company may be in a position to get disposal trucks, acquire a dumping site or rights to one, acquire necessary additional equipment and constantly seek to improve to be a leader in the industry of waste management.

These surely are the last day of the latrine toilet.


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