How are Water Quality Standards Developed in South Africa?

In a water-scarce nation like South Africa, the development of robust and effective Water Quality Standards is not merely a technical exercise but a critical component of national security, public health, and sustainable development. These standards, which define the desired state of water bodies and the quality required for various uses, are crucial for managing pollution, protecting ecosystems, and ensuring the availability of safe water for all. Unlike a one-size-fits-all approach, their development in South Africa is a multifaceted, scientific, legal, and consultative process, primarily driven by the Department of Water and Sanitation (DWS), as mandated by the National Water Act (Act 36 of 1998).

The process of developing and refining Water Quality Standards in South Africa can be understood through several key stages and considerations:

1. Scientific Research and Data Collection

The foundation of any credible water quality standard lies in sound scientific understanding. This involves:

• Understanding Contaminant Impacts: Extensive research is conducted to determine the effects of various pollutants (e.g., chemicals, heavy metals, pathogens, nutrients) on human health, aquatic organisms, and ecosystem integrity. This includes toxicology studies, epidemiological data analysis, and ecological risk assessments specific to South African conditions and biodiversity.
• Water Chemistry and Hydrology: Understanding the natural background water quality of different catchments, their hydrological characteristics, and how pollutants behave and transform in diverse aquatic environments (rivers, dams, groundwater, estuaries).
• Ecosystem Functioning: Research into the specific requirements of South Africa’s diverse aquatic ecosystems to maintain their ecological health, biodiversity, and the services they provide (e.g., purification, flood attenuation).
• Technological Feasibility: Assessing the availability and effectiveness of treatment technologies for both industrial effluents and municipal wastewater to remove specific pollutants to desired levels.

2. Identifying Designated Water Uses and Risk Assessment

South Africa’s approach to water quality is use-driven. The intended use of a water body significantly influences the stringency of the standards applied. This involves:

• Classification of Water Resources: The National Water Act requires the classification of water resources based on their “present and future uses.” This includes categorising water bodies for:
  • Domestic Use (Potable Water Supply): Requiring the most stringent standards, typically aligned with SANS 241 (South African National Standard for Drinking Water).
  • Agricultural Use: Including irrigation and livestock watering, with specific requirements to prevent harm to crops, animals, or human consumers of agricultural products.
  • Industrial Use: Varying widely depending on the industrial process (e.g., cooling, processing, waste disposal).
  • Recreational Use: Considering risks from pathogens for activities like swimming, boating, and fishing.
  • Ecological Reserve: Ensuring sufficient water quantity and quality to protect basic human needs and aquatic ecosystems, which is a fundamental right and responsibility under the National Water Act.
• Risk-Based Approach: For each designated use, a comprehensive risk assessment is conducted. This evaluates the likelihood and severity of adverse effects from specific pollutants, considering exposure pathways and the vulnerability of the receiving environment or human population.

3. Setting Resource Quality Objectives (RQOs)

A cornerstone of South Africa’s water quality management framework, RQOs are a departure from generic, nationwide numerical standards for all parameters. Instead, they are:

• Site-Specific Targets: RQOs are developed for specific water resource units (e.g., a particular river reach, dam, or aquifer). They define the desired state of the water resource in terms of its quality, quantity, and characteristics of its aquatic ecosystems.
• Reflecting Designated Uses and Ecological Reserve: The RQOs for a specific water resource are derived from its classification and the need to protect the ecological reserve. They ensure the water is “fit for purpose” for its various designated uses.
• Qualitative and Quantitative Statements: RQOs are not just numerical limits; they include qualitative descriptions of the desired ecological state (e.g., “healthy fish populations,” “clear water”) alongside quantitative parameters (e.g., chemical concentrations, flow regimes, turbidity levels).
• Informed by Stakeholder Engagement: The process of setting RQOs often involves extensive consultation with local communities, industries, environmental groups, and other water users in the catchment to ensure that the objectives are relevant, achievable, and supported by those directly affected.

4. Establishing Effluent Discharge Limits and General Authorisations

Once RQOs are set for a receiving water body, the DWS develops mechanisms to ensure that discharges from point sources (e.g., industries, wastewater treatment works) do not cause the water body to fall below its RQOs:

• Site-Specific or Industry-Specific Limits: Discharge limits for pollutants in treated wastewater are determined based on the assimilative capacity of the receiving water body and the established RQOs. These limits can be specific to a particular discharger or apply broadly to certain types of industries.
• General Authorisations (GAs): For common, lower-risk water uses or discharges, the DWS may issue GAs. These are published notices that specify conditions and water quality limits that must be met without the need for an individual water use license, provided the activity falls within the scope of the GA. This streamlines the regulatory process while still ensuring environmental protection.
• Waste Discharge Standards: These are a form of effluent limit, specifying the maximum permissible concentration of various substances in wastewater before it is discharged into a water resource.

5. Legal and Regulatory Framework

The development and enforcement of Water Quality Standards are underpinned by a robust legal framework:

• National Water Act (Act 36 of 1998): This is the primary legislation governing water resources in South Africa. It provides the legal basis for classification, setting RQOs, issuing licenses, and enforcing compliance.
• Water Services Act (Act 108 of 1997): Focuses on the provision of water services (potable water and sanitation) and ensures compliance with drinking water quality standards (SANS 241).
• Regulations and Guidelines: The DWS publishes specific regulations (e.g., for wastewater discharge, dam safety, water use charges) and guidelines that elaborate on the broad principles laid out in the Acts.
• SANS 241 (Drinking Water): While not developed by DWS directly, this standard is adopted and enforced by the DWS and local municipalities, setting the benchmark for potable water quality.

6. Public Participation and Consultation

Given the widespread impact of water quality standards, public and stakeholder participation is crucial:

• Transparency: The DWS typically makes proposed classifications, RQOs, and new regulations available for public comment.
• Stakeholder Engagement: Workshops, public meetings, and formal comment periods allow industries, environmental groups, local communities, water users, and experts to provide input, raise concerns, and contribute to the finalisation of standards. This ensures that the standards are technically sound, socially acceptable, and economically viable.

7. Review and Adaptation

Water quality standards are not static. The development process includes a commitment to continuous improvement:

• Monitoring and Assessment: Regular monitoring of water quality in rivers, dams, and estuaries, coupled with compliance monitoring of discharge permits, provides data on the effectiveness of existing standards.
• Scientific Advancement: New scientific understanding of pollutants, ecological processes, and treatment technologies may necessitate revisions.
• Changing Pressures: Population growth, industrialisation, climate change, and land use changes can introduce new challenges, requiring standards to be adapted to address emerging threats.
• Periodic Review: The DWS periodically reviews and updates water quality policies, classifications, and RQOs to ensure they remain relevant and effective in a dynamic environment.

In summary, the development of Water Quality Standards in South Africa is a complex, iterative process that balances scientific rigor, legal mandates, socio-economic considerations, and broad stakeholder engagement. It is a continuous endeavour to protect the nation’s vital water resources for current and future generations, ensuring they are fit for purpose and support a healthy and sustainable society. Sources