Borehole water treatment

Borehole supply carries risk that municipal water does not: the water is untreated, quality varies seasonally, and a pump failure or fouled filter stops the whole site. Most Southern African boreholes present some combination of suspended solids (drilling fines, sand), dissolved iron and manganese, hardness, and in coastal or deep aquifers elevated TDS. A water analysis is the non-negotiable first step — treating an unmeasured supply is guesswork, and equipment selected on guesswork gets replaced twice.

Sediment comes out first. For sand and grit at the wellhead, a string-wound or washable pleated cartridge ahead of everything else protects downstream equipment; for sustained solids loading, a backwashing media filter with graded sand or clinoptilolite carries far more capacity between service events than any cartridge. Size media vessels on linear velocity — 10–25 m/h service flow for sand — not on tank volume.

Dissolved iron above roughly 0.3 mg/L stains fittings and fouls membranes and resin. Catalytic manganese-dioxide media oxidise and trap iron and manganese in one vessel, but demand a genuine backwash rate of 30–35 m/h; an undersized valve or pump is the usual cause of a failed iron filter. Where hydrogen sulphide gives the water a characteristic odour, the same catalytic bed handles moderate levels.

Hardness scales geysers, elements and RO membranes. A softener sized on measured hardness and real daily consumption — with a volumetric valve so regeneration follows actual use — protects the installation at predictable salt cost. Where TDS itself is the problem, reverse osmosis is the correct tool; see the brackish water RO application for staging and pretreatment rules.

Every category this application needs is stocked in Cape Town and Johannesburg, with lead-time bands and stock status shown on every line.