Abstract
Most rural communities in the Eastern Cape province of South Africa rely heavily on both surface and groundwater sources for domestic and agricultural uses. However, water service delivery and water resources quality are challenged by infrastructural and environmental issues. This study presents the results of a monitoring programme of both groundwater (via springs/ boreholes) and surface water (streams/river-linked points) in selected villages within King Sabatha Dalindyebo, Nyandeni, Mhlontlo, and Ntabankulu local municipalities. The objectives were to: (i) assess physicochemical parameters, major elements, and trace metals water quality status of the water sources, (ii) compare the water quality with the South African National Standard guideline for drinking and domestic use, (iii) investigate seasonal variation across local municipalities and risk assessment from water sources, (iv) provide baseline information to inform communities. Sampling campaigns covered four seasons (autumn, spring, summer, and winter) and measured parameters including pH, temperature, EC, TDS, turbidity, free chlorine, nitrate, phosphate, sulfate, COD, ammonia, total hardness, Mg, Ca, K, Na, Zn, Fe, As, Cd, Sb, Mn, Ni, Cr, and Cu. The quality of groundwater and surface water was assessed using the water quality index (WQI), while health risk assessment by trace metal contamination was determined using the trace metal evaluation index (TMEI), trace metal toxic load (TMTL), trace metal pollutant index (TMPI) and hazard index (HI). The turbidity values across sampling locations ranged from 0.41 to 117 NTU in May 2023 and from 0.16 to 116 NTU in September 2023, respectively. Results indicate that while groundwater and surface water sources met guideline limits for most major elements, several springs and surface water from Mhlontlo sites exhibited high turbidity in September 2023 (8.31 to 116 NTU) that led to high WQI values. In some cases, nitrate/or phosphate concentrations exceeding the recommended thresholds of 11 mg/L for nitrate and 1.0 mg/L for phosphate from streams (Gubevu, Lower Xhongora, Mavundleni, and Didi) and springs (Sikhobeni, Gubevu, and Ezinkonzweni) during the spring season. Surface water was more variable, reflecting influences from land use, agricultural runoff, sanitation infrastructure, and seasonal changes. Approximately 90% of the selected villages within the study municipalities exhibited a potential non-carcinogenic risk to children, women, and men, with a HI value exceeding 1. A rondom forest (RF) model have been developed for water quality prediction in real-time. The study findings suggest that water sources are not safe or clean for domestic use; therefore, continuous monitoring is necessary.