Hydrogeochemical Evaluation of Groundwater Quality in Eku, Delta State, Nigeria

Groundwater is the principal source of drinking water for millions of rural and peri-urban dwellers in Nigeria, yet its quality remains largely unmonitored. This study evaluates the hydrogeochemical quality of groundwater in Eku, Ethiope East Local Government Area, Delta State, Nigeria, and its suitability for human consumption. Groundwater samples were collected from five hand-dug wells and subjected to physicochemical and bacteriological analyses following American Public Health Association (APHA, 2020) standard methods. Parameters assessed include pH, temperature, dissolved oxygen, total dissolved solids, turbidity, hardness, cyanide, nitrate, chloride, sulphate, bicarbonate, calcium, magnesium, heavy metals (cadmium, copper, lead, zinc), and total coliform counts. Results were compared against World Health Organization (WHO, 2021) guideline values. Total dissolved solids (68.10–123.50 mg/L), turbidity (2.0–3.8 NTU), and total hardness (47.0–56.0 mg/L) fell within permissible limits. However, pH values (4.00–6.30) were below the recommended range (6.5–8.5), lead concentrations exceeded the 0.01 mg/L WHO limit across all sites, and coliform counts surpassed the zero-threshold standard. Groundwater in Eku requires pH correction, heavy metal remediation, and disinfection before safe consumption. Periodic monitoring, improved sanitation infrastructure, and community education are urgently recommended.