Groundwater quality evaluation: a case study of Igando waste dumpsite, southwestern Nigeria

Abstract The quality of groundwater samples around Igando area, Lagos State, Nigeria was investigated with the aim detecting possible influence dumpsites on nearby aquifers. Thirty-seven (37) were evaluated for their suitability in drinking and agricultural purposes. Physical parameters determined situ using portable multi-meter. Flame absorption used to determine concentrations major cations while ion chromatography titrimetry anions’ concentration. Bacteriological test conducted multiple tube technique. Results in-situ physical revealed pH range 7.01–7.79, EC 20–880 μS/cm TDS from 13–590 mg/L. Laboratory analyses showed Ca 2+ concentration ranging 1.60–72.80 mg/L HCO 3 − 19.52–204.96 as dominant ions. None ions’ exceed WHO limit. Water Quality Index (WQI) classification that all fall within good excellent water categories. majority are suitable irrigation indices such Sodium Adsorption Ratio (SAR), Kelly’s ratio (KR), Magnesium Hazard (MH). low total bacterial count E-coli absence making safe drinking. Piper diagram indicated two main water-facies (Ca–HCO Mixed Ca–Mg–Cl). Gibbs’s plots primarily influenced by rock weathering, precipitation also contributed. Chloro-Alkaline confirmed direct ion-exchange process. Cluster four groups: first anthropogenic activities study second third lithological origin ions group 4 dissolved waters. can be said fair-good, thus suggestive minimal interactions between area at time testing.