One size doesn’t fit all – especially when it comes to managing waste. In South Africa, where municipal infrastructure isn’t always available, many properties rely on off-grid sewage systems to manage household and commercial wastewater. Whether a home, lodge, or new development, choosing the right solution is essential for environmental compliance, cost control, and long-term functionality.
This blog compares two of the most common options for onsite wastewater management in SA: septic tanks and conservancy tanks. We’ll walk you through the core differences, legal requirements, and site suitability considerations so you can make the best decision for your property.
What Is a Septic Tank Used For?
A septic tank is an underground unit designed to process and partially treat wastewater on-site before safely dispersing it into the surrounding soil. It separates and breaks down solid and liquid waste through anaerobic digestion, reducing the organic load of the effluent before it’s released (i.e. lowering the amount of biodegradable material that could harm the environment).
The system typically features two chambers. In the first, solids settle into a sludge layer while fats, oils, and grease rise to the top. In the second chamber, the clearer effluent is drawn off and sent to a soakaway or leach field, where the soil provides final purification.
Calcamite’s septic tanks include an inner chamber that enhances this separation process, producing a cleaner discharge for improved soakaway performance. These systems are ideal for larger plots with permeable soils (like rural homes, lodges, or eco-estates) and are designed to comply with SANS 10400 Part P regulations. (More on that coming up.)
What Is a Conservancy Tank?
A conservancy tank is a sealed, watertight container used to collect and store all wastewater from a property until it can be pumped out and taken to a treatment facility. Unlike septic tanks, conservancy systems don’t treat wastewater on-site, they simply contain it. This makes them ideal in areas where soil conditions or environmental regulations don’t allow for drainage into the ground.
Because conservancy wastewater tanks don’t require a soakaway or filtration system, they’re often used on smaller plots, rocky terrain, or sites with high water tables, where wastewater absorption is not possible. They’re also a common choice where local by-laws prohibit effluent discharge into the soil.
Conservancy Tank vs Septic Tank in South Africa: Key Differences
Choosing between a conservancy or septic tank depends on your property’s soil type, size, location, and how often the system will be used. Here’s a quick breakdown of some important considerations:
Installation and Maintenance Costs
- Septic tanks have higher upfront installation costs due to the need for a soakaway system, but need minimal long-term maintenance (usually annual desludging).
- Conservancy tanks are cheaper to install, but come with ongoing pumping costs, especially in high-use settings.
Site Suitability Factors
- Septic tanks work best in rural or off-grid sewage systems with permeable soils and low water tables.
- Conservancy tanks are preferred in urban areas or in places with high groundwater levels where effluent can’t drain safely.
Usage Frequency and Volume
- A septic tank is ideal for permanent residences with consistent use.
- A conservancy tank suits holiday homes, small buildings, or part-time dwellings where water use is lower.
Environmental and Legal Considerations in South Africa
Onsite wastewater management in SA is governed by a combination of national standards, municipal by-laws, and environmental policies that aim to protect public health and water sources. Whether you’re installing a conservancy or septic tank, you’ll need to comply with SANS 10400 Part P. This outlines the technical requirements for drainage systems, including tank design, construction, and placement.
View the full SANS 10400-P document here
Learn more about non-waterborne sanitation requirements
- Septic tanks must be watertight, vented, and correctly sized to allow a minimum 24-hour retention time.
- Conservancy and wastewater tanks must meet minimum volume standards (typically 7,000 L for domestic use) and must be accessible to vacuum trucks for routine emptying.
- Soakaways and French drains typically require soil percolation testing and a safe distance from dwellings.
Depending on your location, you may also need approval from your municipality.
Installation guidance for sewerage tanks from SACAP
Open By-laws: Example sewage disposal regulations
Failure to comply may result in costly penalties or having plans rejected. To promote sustainable practices, the Department of Water and Sanitation (DWS) supports a National Faecal Sludge Management Strategy that emphasises containment, safe emptying, and proper treatment.
Explore the DWS Faecal Sludge Management Framework
Calcamite blog: Key specifications for compliant wastewater treatment
Summary Table: Septic vs Conservancy Tanks
| Feature | Septic Tank | Conservancy Tank |
| Treatment Type | Primary treatment + soakaway drainage | No treatment – sealed storage only |
| Cost Over Time | Lower (less frequent maintenance) | Higher (requires regular emptying) |
| Best For | Large rural plots with permeable soil | Urban, small, or rocky sites |
| Maintenance | Occasional desludging (annually or as needed) | Frequent emptying based on usage volume |
Partnering for Safe, Sustainable Sanitation
Septic tanks offer on-site treatment, and are a great solution for properties with permeable soil and space for a soakaway. Conservancy tanks provide secure, sealed containment where drainage isn’t possible. Whatever your site, Calcamite offers a wastewater solution for developers and individuals that meets regulatory requirements and supports long-term performance.
Explore Calcamite’s range of Septic Tanks and Conservancy Tanks
Contact us for guidance and expert installation
