Industry brief 2020 Reusing wastewater

The document argues that on-site wastewater treatment is a key intervention to mitigate South Africa's projected 30% water supply deficit by 2030. It details the processes for treating organic wastewater (greywater and blackwater) to non-potable standards for uses such as toilet flushing and irrigation. The brief outlines three technology variants—tank assemblies, pre-fabricated systems, and brick-and-mortar constructions—while highlighting operational risks like bacterial die-off due to variable loading. It also maps the regulatory landscape, including the National Water Act (1998) and SANS 30500:2019, and provides case studies from the Western Cape demonstrating cost savings and regulatory compliance.

• South Africa is facing significant water scarcity and is expected to experience a 30% water supply deficit by the year 2030.
• On-site treatment of organic wastewater—specifically greywater (lightly contaminated) and blackwater (containing human excrement)—can provide non-potable water for applications such as irrigation, vehicle washing, and toilet flushing.
• Biological treatment of organic wastewater typically involves a four-step process: screening, primary settling (anaerobic digestion), secondary settling (aerobic treatment via methods like Activated Sludge or Sequential Batch Reactor), and final clarification/disinfection using UV, ozone, or chlorination.
• On-site wastewater systems face several operational barriers, including the risk of killing treating bacteria through inorganic contaminants, bacterial die-off during periods of low organic loading, and high upfront costs.
• The regulatory framework for wastewater in South Africa includes the National Water Act (1998), which regulates environmental discharge, and the National Environmental Management Act (1998), which triggers Basic Assessments or Scoping/EIA processes based on throughput capacity (e.g., 2,000 to 15,000 kl/day for Basic Assessment).
• SANS 30500:2019 provides voluntary standards for non-sewered sanitation systems, but these apply only to pre-fabricated products and do not supersede the mandatory requirements of the National Water Act.
• Case studies in the Western Cape indicate that on-site treatment can be more cost-effective than centralized systems; for example, a study on informal settlements found decentralized treatment to be the lowest cost technology option compared to centralized connections or chemical toilets.

APA

Kruger, R. (2020). Industry brief 2020 Reusing wastewater. GreenCape. https://greencape.co.za/assets/WASTEWATER_TREATMENT_INDUSTRY_BRIEF_WEB-13-11-2020.pdf

Chicago

Kruger, Raldo. Industry brief 2020 Reusing wastewater. GreenCape, 2020. https://greencape.co.za/assets/WASTEWATER_TREATMENT_INDUSTRY_BRIEF_WEB-13-11-2020.pdf.

Wikipedia

{{cite report |last1=Kruger |first1=Raldo |title=Industry brief 2020 Reusing wastewater |publisher=GreenCape |date=2020 |url=https://greencape.co.za/assets/WASTEWATER_TREATMENT_INDUSTRY_BRIEF_WEB-13-11-2020.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{kruger2020industry, author = {Kruger, Raldo}, title = {{Industry brief 2020 Reusing wastewater}}, institution = {GreenCape}, year = {2020}, url = {https://greencape.co.za/assets/WASTEWATER_TREATMENT_INDUSTRY_BRIEF_WEB-13-11-2020.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }