Brackish Water Reverse Osmosis Desalination System – Cape Town Farm

Project Overview:
We designed, supplied, and installed a high-capacity brackish water reverse osmosis (RO) system for a borehole on a farm outside Cape Town, providing purified water for household use, livestock, and greenhouse irrigation.

The Challenge:
The borehole water had extremely high sodium, chloride, hardness, and iron, with TDS around 9000 mg/L—roughly one-third the salinity of seawater. Off-the-shelf commercial RO systems in South Africa handle a maximum of 3000 mg/L TDS, so a custom solution was required.

Solution – System Design & Pretreatment:

1. Ozone circulation: Oxidizes volatile constituents.
2. Activated filter media: Removes suspended solids.
3. Katalox iron removal: Eliminates dissolved iron.
4. Granular activated carbon: Absorbs tastes, odors, VOCs, and TOCs.
5. Scale inhibitor dosing: Protects membranes from hardness.

Reverse Osmosis System:

A. Two-stage pre-filtration down to 1 micron.
B. Low-pressure brackish water RO membranes for high TDS.
C. Stainless steel valves, gauges, and high-pressure pump.
D. ROC Smart RO controller with conductivity meter and automated tank level, pressure, and pre-filtration controls.
E. Self-backwashing on startup/shutdown.

Client Benefits:

*Reliable access to pure, potable water.
*Safe water for household, livestock, and irrigation.
*Reduced dependence on external water sources.
*Long-term, low-maintenance operation despite extreme TDS levels.

Key Achievement:
Successfully treated water with TDS of 9000 mg/L, exceeding conventional RO limits, delivering safe, versatile water for the farm.