Abstract
Groundwater is the major supply of drinking water and other uses in the Great Kordofan states, Sudan. This study aims at evaluating the groundwater quality in that area through different approaches. The mean and standard deviation of the examined physiochemical parameters of 44 groundwater samples were found as follows: pH 7.3 +/- 0.3, temperature 31.2 +/- 8.4 degrees C, turbidity 19.5 +/- 69.1 nephelome-tric turbidity units, and electrical conductivity (EC) 1032.8 +/- 980.8 mu S/sec, while the contents (mg/L) of the other physiochemical parameters were found as follows: total dissolved solids (TDS) 686.5 +/- 689.9, total alkalinity (TA) 226.5 +/- 141.5, total hardness (TH) 267.2 +/- 450.6, chloride 47.6 +/- 81.5, fluoride 0.3 +/- 0.5, nitrate 35.5 +/- 46.4, nitrite 16.1 +/- 46.3, ammonia 0.3 +/- 0.7, iron 0.3 +/- 0.6, calcium 57.9 +/- 111.8, magnesium 17.3 +/- 14.3, and the total sodium and potassium 78.1 +/- 57.6. Wide variation was attributed to different natural and manmade factors. The maximum turbidity, EC, TDS, TA, and TH, besides all examined ions, exceeded the maximum permissible limits recommended by the World Health Organization. The physiochemical parameters were subjected to hierarchical cluster analysis and the K-means clustering methods followed by applying the Water Quality Index (WQI). Based on the Canadian guidelines, WQI showed that the distribution of the levels of the groundwater quality in the study area was as follows: 7% poor quality, 48% marginal quality , 29% fair quality, and 16% good quality. Moreover , the health risk from the exposure of nitrates through water ingestion was estimated. The hazard index of the mean and the maximum nitrates was > 1, indicating a high possibility to occur adverse non-carcinogenic health risk.