Determining the chemical and bacteriological quality of drinking water in the healthcare facilities storage tanks, city of Tshwane

Hunadi  Moloi

Access to safe drinking water at the point-of-use (POU) is a critical yet inequitably distributed determinant of public health in South Africa. This cross-sectional study examined the physicochemical parameters and heavy metal concentrations in drinking water at selected primary healthcare clinics within the City of Tshwane Metropolitan Municipality. The research utilized a purposive, vulnerability-focused sampling design, targeting fifteen (n=15) clinics characterized by older building infrastructure (66.7%, n=10) and locations within township areas (86.7%, n=13), predominantly in a single sub-district (93.3%, S1). Samples were collected across two temporal periods (pre- and post-seasonal rains) and analysed for compliance with the South African National Standard (SANS 241:2015) and World Health Organization (WHO) guidelines. The results revealed a bifurcated profile of water safety. Microbial risk from faecal contamination was effectively managed, with Escherichia coli not detected in any sample, and key operational parameters such as pH, chloride, and iron remained within regulatory limits across both sampling rounds. However, analysis of heavy metals indicated significant and stratified chemical hazards. Copper and lead were present in low concentrations across most samples, with a critical subset exhibiting sporadically elevated levels, a pattern indicative of localized corrosion and stagnation within aging premise plumbing. Statistical correlation analysis (Pearson’s r) further identified a very strong, significant positive relationship between arsenic and cadmium (r = 0.767, p < 0.001), strongly suggesting a common external source, such as industrial effluent or geogenic leaching. Metals including chromium, mercury, manganese, and nickel were detected at consistently low levels, indicating a pervasive, low-level background contamination. The study concludes that while the municipal supply maintains microbial integrity and general chemical stability, POU water quality in these high-vulnerability settings is compromised by a dual-threat model: (1) an infrastructure-dependent hazard from leaching lead and copper, and (2) a systemic, source-related burden of co-occurring toxic metals like arsenic and cadmium. The findings necessitate a paradigm shift in water safety management, moving from a sole focus on treatment works output to integrated POU protection. Key recommendations include the immediate implementation of point-of-use flushing protocols in older buildings, the initiation of targeted corrosion control programs, the amendment of monitoring regulations to include mandatory POU metal testing in public facilities, and a comprehensive source water investigation to identify and mitigate the origin of correlated toxic metals.