South Africa’s updated SANS 241 (the South African National Standard for drinking water quality) signals a fundamental shift in how potable water quality is managed, moving the sector away from tick box compliance towards a proactive, risk based approach.

SANS 241 defines the minimum requirements for potable water to be deemed safe for human consumption, covering microbiological, chemical, physical and aesthetic water-quality parameters. What this means in practice: water that complies with SANS 241 supports long-term health, reduces risks of waterborne diseases, and ensures that drinking water meets rigorous quality, safety, and taste standards. The standard is reviewed every five years.

“We initially revised the standard, went through two iterations, and circulated it for public comment. The volume of feedback (53 pages of 255 individual comments) received was so significant that we decided to redo the entire standard,” says Leanne Coetzee, specialist consultant, Waterlab.

Coetzee was the previous chairperson of the South African Bureau of Standards (SABS national committee – SABS/TC147, Water – that prepared the standard. Debbie Trollip is the current chair of the committee.

Home-grown

“SANS 241 is unique. While many South African standards are typically adopted from the International Organization for Standardization (ISO), often with minor adjustments for local conditions, SANS 241 is a distinctly home-grown standard. It is referenced in the Regulations relating to Compulsory National Standards and Measures to Conserve Water,” explains Coetzee.

Despite the existence of World Health Organisation (WHO) Guidelines for Drinking Water Quality, Australia Drinking Water Guidelines, the United States Environmental Protection Agency the Drinking Water Directive (European Union) Drinking Water Regulations, there has always been a need for an African drinking water standard. SANS 241 is often adopted by countries in the Southern African Development Community (SADC) region.

Unlike many international drinking water guidelines and directives, SANS 241 is a shorter document and frequent references the WHO Drinking Water Guidelines, particularly for health-based limits that are continuously updated by experts.

“We do not want to reinvent the wheel,” adds Coetzee.

Thinking risk

The latest version of SANS 241 puts an emphasis on proactive risk management. People using the standard need to shift from ‘following a table’ to placing risk at the centre of water quality management.

“One of the committee’s biggest concerns is getting people to think in terms of risk, rather than simply ticking off values in a table,” states Coetzee.

“Historically, many water providers have focused on meeting numerical limits in the standard’s tables. However, this approach often led to situations where critical non-compliance issues were masked by strong performance in less important parameters.”

The new approach challenges this mindset. Water service providers are now required to start with a comprehensive risk assessment. This includes analysing raw, treated and critical points within the distribution network, as well as onsite assessment of the catchment for potential contamination sources such as informal settlements, agricultural runoff or industrial activity.

“A proper risk-based assessment under SANS 241 is not confined to laboratory data alone, but combines analytical results with what is physically observed on the ground,” says Coetzee.

By physically inspecting upstream activities such as informal settlements, agriculture, industry or livestock, risks are identified that are not yet reflected in the water quality results. This ensures that monitoring programmes are proactive and tailored to the specific conditions of each water supply system.

“Monitoring programmes will change based on risk assessments as they must be specific to a water supply system including its catchment area. Table 2 in SANS 241 sets out the system-specific risk defined parameters that may need to be monitored in a drinking water supply. Unlike Table 1, which lists mandatory parameters that must always be tested, Table 2 is driven by risk. It includes a wide range of chemical, organic and aesthetic parameters that must be monitored as part of the risk assessment. If identified as a potential risk within a specific water supply system, the identified parameters must be included into the routine monitoring programme” explains Coetzee.

Limited resources

This shift comes at a critical time for South Africa, where constrained municipal resources, ageing infrastructure and declining raw water quality are placing increasing pressure on treatment systems. The revised standard acknowledges these realities and attempts to balance public health protection with what is practically achievable on the ground. Instead of conducting unnecessary tests, the risk-based approach forces entities to focus on the tests that are needed.

Coetzee gives a practical example: “As river systems become increasingly polluted, treating drinking water becomes more challenging, with a corresponding rise in organic contamination in drinking water plant catchment areas. While SANS 241 identifies the protozoan parasites that should be monitored, testing can be costly – a single Cryptosporidium analysis by a SANAS 17025 laboratory can cost a municipality up to R8 000. As a result, the standard emphasises the importance of maintaining low turbidity levels as a practical way to reduce the risk of pathogens entering drinking water.”

This pragmatic, risk-based approach also influenced decisions around the scope of the standard. The technical committee would have liked to include more organic contaminants into the standard (such as Haloacetic acids), but decided against this due to a lack of local laboratory capacity.

“An additional list of organic contaminants have been included in an annex, with the intention of incorporating them into the next revision once laboratories are better equipped,” states Coetzee.

She adds that sending water samples overseas or to distant laboratories with greater testing capacity offers limited value, particularly when results take weeks to return. While they may indicate, for example, what occurred in a catchment, the delay removes the opportunity for immediate response, by which time the water has already been consumed.

“There is ongoing concern around the financial burden these tests place on entities, and we have taken this into account by refining the standard to focus on what is truly necessary.”

“The intention is not to reduce oversight, but to prioritise meaningful monitoring that addresses real risks. However, public health remains non-negotiable, and the standard cannot be compromised at the expense of safe drinking water,” states Coetzee.

Important terms, definitions and clauses

When navigating the standard, it is critical that all definitions are read. Rural boreholes are no longer treated the same as a water treatment plant in terms of water quality monitoring requirements.

A water supply system (WSS) is defined as an asset system that includes the raw water abstraction point, the water treatment plant (WTP) up to the final water, and the distribution network up to the point of delivery to consumers. Within the same supply area, water quality can vary due to factors such as geographical location, infrastructure age, distance from the WTP, supply from multiple WTPs, or a combination of these. Each distinct water quality zone should therefore be managed as a separate WSS, with distribution network sample points selected to accurately represent each system.

A borehole system is an asset system that utilises groundwater of low water quality variability, where disinfection is practised, serving a maximum population of 5 000 people. Sampling points of a borehole system includes the final water and a limited number of distribution network sample points.

“SANS 241 makes provision for groundwater use in rural areas where water quality is generally unpolluted. In these cases, monitoring frequency and the number of required tests are reduced, with a focus on parameters specific to borehole systems. Every borehole system must have a comprehensive risk assessment of the raw water, final water, and key points in the distribution network. A full SANS 241 analysis is still required every second year with a reduced list of parameters required twice a year. Where several boreholes feed into one supply, the revised SANS 241 allows operators to monitor the combined water quality at the reservoir, rather than sampling every individual borehole,” notes Coetzee.

However, systems that utilise groundwater where water quality varies, or serves populations exceeding 5000 people, are classified as Water Supply Systems and should meet the standard requirements for a water supply system.

Additions and changes

Coetzee points out that when non-compliance occurs, there is often uncertainty around the appropriate response. To address this, the standard now includes a section on management of non-compliant results, providing more explicit direction on how to respond. When a water quality result is non-compliant, the non-compliant result must be investigated to determine the risk. The nature and urgency of the required investigation will vary depending on the risk posed, or indicated by, the non-compliant parameters.

One of the most notable technical changes is the tightening of limits such as in the case of turbidity. The turbidity standard used to be 5 NTU for aesthetic purposes and 1 NTU as the operational limit. Now the requirement is 1 NTU. This means municipalities should target much lower turbidity levels – around 0.5 NTU or even 0.3 NTU for the final water– to keep risk low and avoid drifting into non-compliance. In this framework, 1 NTU is treated as an incident threshold: if turbidity exceeds 1 NTU, it is classified as an incident and must be managed accordingly.

“Another important addition is the renewed emphasis on protecting infrastructure. Parameters such as alkalinity, hardness and calcium carbonate stability, previously excluded from the core standard, are now highlighted as essential for preventing corrosion and pipe damage. This reflects a broader understanding that water quality is not only about health, but also about maintaining the integrity of distribution systems,” notes Coetzee.

A number of new or expanded parameters have been introduced, largely to strengthen the risk-based approach and better reflect emerging contaminants and treatment realities.

One of the key additions is intestinal enterococci, which serves as an additional microbiological indicator, particularly in brackish or saline water systems. If water has a conductivity over 154 mS/m, intestinal enterococci must be tested. This complements E. coli and provides a more robust indication of faecal contamination risk in certain conditions. There is no longer a need to test for total dissolved solids as conductivity can be used to provide an estimate thereof.

Some new organics are included in the standard such as benzene, atrazine, and dichlorodiphenyltrichloroethane (DDT), all of which are linked to industrial activity or agricultural runoff or are classified as persistent organic pollutants and are assessed based on catchment-specific risk.

There has also been a refinement in how colour is measured, with the introduction of both apparent colour and true colour. Apparent colour reflects what the consumer actually sees at the tap (aesthetic risk), while true colour is measured after filtration and is more indicative of the dissolved components in the water(operational risk). This change recognises the importance of both aesthetic and operational water quality.

There is also increased attention on disinfection byproducts, such as bromate, particularly in systems using advanced disinfection methods like ozone or onsite hypochlorite generation. These compounds can form during treatment and pose long-term health risks if not properly managed.

Importantly, SANS 241 also introduces a list of parameters of concern in an annex. These are not yet mandatory but highlight emerging contaminants such as pharmaceuticals, pesticides, and PFAS. Their inclusion signals where the standard is likely heading and encourages utilities to start incorporating them into risk assessments where feasible.

Ultimately, the revised SANS 241 standard signals a maturation of South Africa’s water quality framework. It recognises that ensuring safe drinking water is not about blindly following a table, but about understanding and managing risk in a complex and evolving environment. Clean, safe drinking water isn’t just a regulatory box to tick – it’s a social imperative, a health necessity, and ultimately foundational to the dignity and well-being of every community.