Using Groundwater Options for managing saline wastewater/brine

This 2019 industry brief by GreenCape examines the challenges and options for managing brine—highly concentrated saline wastewater—produced when companies in Cape Town treat saline groundwater using technologies like reverse osmosis (RO). The document outlines direct discharge and treatment methods, noting that high costs and strict regulatory requirements often make these solutions financially unviable.

• Companies in Cape Town have increased groundwater exploration due to recent droughts, but geohydrologists have identified industrial areas with a high risk of saline groundwater, defined as having a conductivity greater than 170 mS/m or a salts concentration exceeding 1200 mg/l.
• Brine management is categorized into direct discharge and brine treatment. Direct discharge options include sewer discharge (which may require blending with process water to lower salinity), evaporation ponds, and sea outfalls. Treatment options focus on volume minimization or resource recovery through technologies such as multi-stage membrane filtration, eutectic freeze crystallization, and evaporative crystallization.
• Direct disposal of brine to landfills in the City of Cape Town is limited to the Vissershoek hazardous Class A landfill, with costs between R1 500/kl and R2 550/kl. However, a liquids-to-landfill ban effective August 2019 prohibits wastewater discharge, though almost-solid brine waste is permitted until 2021.
• The financial and technical barriers to brine management are significant. Sea outfall pipelines have high capital costs of approximately R10 million/km and strict conductivity limits of 500mS/m. Treatment technologies also face high costs: multi-stage membrane filtration costs R1.5–3 million/MLD per stage, while eutectic and evaporative crystallization require R80-100 million/MLD in capital and high energy costs of approximately R100-150/kl.
• Because brine treatment is often too costly, GreenCape suggests that businesses extracting saline groundwater should use the water in a 'fit-for-purpose' manner (e.g., for cooling or general cleaning) to avoid generating brine via RO systems. Additionally, companies are encouraged to partner and invest in decentralized treatment solutions to improve the business case.

APA

Fundikwa, B. (2019). Using Groundwater Options for managing saline wastewater/brine. GreenCape. https://greencape.co.za/wp-content/uploads/2022/10/Brine-Industry-Brief-WEB-12-4-2019-3.pdf

Chicago

Fundikwa, Bridget. Using Groundwater Options for managing saline wastewater/brine. GreenCape, 2019. https://greencape.co.za/wp-content/uploads/2022/10/Brine-Industry-Brief-WEB-12-4-2019-3.pdf.

Wikipedia

{{cite report |last1=Fundikwa |first1=Bridget |title=Using Groundwater Options for managing saline wastewater/brine |publisher=GreenCape |date=2019 |url=https://greencape.co.za/wp-content/uploads/2022/10/Brine-Industry-Brief-WEB-12-4-2019-3.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{fundikwa2019using, author = {Fundikwa, Bridget}, title = {{Using Groundwater Options for managing saline wastewater/brine}}, institution = {GreenCape}, year = {2019}, url = {https://greencape.co.za/wp-content/uploads/2022/10/Brine-Industry-Brief-WEB-12-4-2019-3.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }