Physicochemical and Microbiological Qualities of the Sundays River Estuary in the Eastern Cape Province, South Africa

Freshwater scarcity is a major global issue faced by various regions, and the most common portable water sources globally are estuaries, canals, dams, lakes, and rivers. Existing water resources function as the best sinks for the frequent release of effluents from industrial and residential activities. This common practice often results in water pollution, a deterioration in marine biodiversity, and possible health risks for human populations. This study employed standard analytical methods in assessing the physicochemical and microbial characteristics of water samples collected from the Sundays River estuary in Eastern Cape Province (ECP), South Africa (SA). Microbiological assessment revealed that during the spring season, presumptive Escherichia coli (E. coli) colony counts were 1 cfu/100 mL, while total coliforms (TCs) and fecal coliforms (FCs) were recorded at 42.67 cfu/100 mL and 1 cfu/100 mL, respectively. In the summer season, fecal coliform (FC) counts reached 3.5 cfu/100 mL, while Enterococcus levels were higher, ranging up to 77.75 cfu/100 mL. Furthermore, the average standards of physicochemical parameters assessed in water obtained from both spring and summer seasons ranged as follows: pH (8.71–9.31), temperature (20.98–22.21 °C), turbidity (10–35.55 FNU), total alkalinity (22.25–94.00 mg/L), oxidation–reduction potential (ORP) (8.05–151.6 mV), electrical conductivity (EC) (13,915–40,260 uS/cm), salinity (8.07–25.78 psu), dissolved oxygen (DO) (6.79–7.39 mg/L), total dissolved solids (TDSs) (6960.6–20,125 mg/L), and biochemical oxygen demand (BOD) (0.11–2.94 mg/L). The levels of TDS, EC, turbidity, and salinity in the Sundays River estuary water exceeded the World Health Organization (WHO) guidelines of 2017, rendering the water unfit for even recreational purposes. Additionally, the bacterial levels identified in this study were above the values set by the South Africa Department of Water Affairs (SA-DWAF). The identified microorganisms are perceived as essential indicators of fecal contamination and have the potential to multiply in the environment. Possible pollution may be a result of various municipal effluents consistently discharged into the waterbody.