A septic tank is one of the most common ways to treat wastewater where a property is not connected to municipal sewerage. Looked after properly, a septic system is reliable and cost-effective for decades. This guide covers everything you need to know about septic tanks: how a septic tank works, the main types, how to maintain one, and the South African regulations that apply.
What is a septic tank?
A septic tank is a watertight underground chamber that holds and partially treats household wastewater using natural processes. Wastewater from toilets, sinks, showers, washing machines and dishwashers flows into the tank and separates into three layers: solids sink to the bottom as sludge, fats and oils rise to the top as scum, and the clarified liquid in the middle (the effluent) flows out for further treatment in the drainfield.
How does a septic tank work?
A septic system works without oxygen, so anaerobic bacteria can break down the organic matter in the waste. Separation happens inside the tank: solids and liquids settle out, and the partially treated effluent then flows through an outlet pipe into a distribution line or soakaway. From there it filters down through the soil of the drainfield, where natural organisms remove the remaining contaminants before the water safely re-enters the groundwater. Our detailed explainer on understanding how septic tanks work breaks the process down step by step.
Types of septic tanks and systems
Septic tanks come in several materials and designs to suit different sites and household sizes. Traditional tanks are made from concrete, fibreglass or polyethylene. Where soil conditions or space are limited, alternative systems such as aerobic treatment units or sand-filter systems may be more suitable. Choosing the right type, and sizing it for your household, is essential for reliable performance. See our guides to the types of septic tanks and to septic tank construction, materials, design and installation for help deciding.
Maintaining your septic system
Regular maintenance keeps both the tank and the drainfield working. Have the tank pumped every three to five years depending on its size and the number of people in the home, and arrange periodic inspections to check for leaks and to make sure effluent is not seeping to the surface. Avoid flushing fats, chemicals, wet wipes and other non-degradable items, all of which shorten the life of the system. When it is time for a service, book a septic tank cleaning in Cape Town with our honeysucker team. If problems do appear, our guide to common septic tank problems will help you identify the cause.
Septic tank regulations in South Africa
Septic systems in South Africa must comply with the National Building Regulations and the relevant SANS standards, as well as local municipal by-laws that govern where a tank may be sited and how effluent must be disposed of. If you are installing, moving or decommissioning a tank, check the requirements first; some municipalities require the tank to be pumped and inspected before any work. Our overview of septic tank regulations in South Africa explains the essentials, and the Wikipedia entry on septic tanks offers useful general background.
That covers the essentials of how a septic tank works and how to look after it. For a pump-out, inspection or advice on a new system, contact Drain Blasters anywhere in the Western Cape.
