Multivariate statistical assessment and spatial distribution of groundwater contamination in Neke and its environs, South-Eastern Nigeria

Groundwater quality in Neke area of southeastern Nigeria was investigated applying multivariate statistical analyses using Statgraphics centurion XVII, ArcGIS 10.2.2 and Surfer 10 software on hydrochemical and bacteriological data from 25 groundwater samples over land cover of about 1283 km2 , in order to unravel the factors influencing ground water quality. From the correlation analysis, Ca2+, Mg2+, K+, and SO42- appear to be the main contributors of the ground water (Total dissolved solids, TDS), Ca2+ shows a high correlation (0.9998) with Mg2+, indicating that the two cation are from same source. Factor analysis and cluster analysis reflect faecal matter contamination through onsite sanitary sewage system, leaching of agricultural waste into the groundwater and weathering and dissolution of host rocks. Groundwater flow pattern is local and controlled by topographic highs, weathering and fracturing of the host rock in the study area. Three dominant factors extracted from the factor analysis were spatially distributed by their factor over the study area. From the calculated water quality index, the groundwater quality in the study area is poor and it was attributed to onsite sanitary sewage and agricultural waste contamination. Key words: Cluster analysis, correlation, Neke area, factor scores, groundwater quality.