ABSTRACT
The study is aimed at determining the hydrogeology of Umuawa area, Southeastern Nigeria. The mapped area covers an extent of about 245 km2 located in Ameki geological Formation of the Anambra Basin. The study area is bounded by the longitude 7º27’0”E to 7º29’0”E and latitude 5º33’0”N to 5º34’40”N. The area is underlain by Nanka sands of the Ameki Formation. The lithology consists of mainly coarse grained sands with abundant intercalations of calcareous shales and thin shelly limestone below and of loose cross bedded white or yellow sands. Ten water samples were collected from the study areas. They include five river samples from River Obowu, River Ikwu, River Obia, River Iyi-ama, River Nkpuru and five groundwater samples. Physico-chemical and microbial analysis were carried out to determine water quality. The result of the samples analyzed showed the variations of the investigated parameters as follows; pH (5.3 to 6.3), EC (13.4 to 155.1)µS/cm, Sal. (0.006 to 0.07)g/l, Col. (ND to 0.7)Pt.Co, Turb. (ND to 1.5)NTU, TSS (ND to 3.2)mg/l, TDS (6.2 to 77.2)mg/l, COD (0.8 to 36.0)mg/l, HCO3 (18.3 to 73.2)mg/l, Na (0.081 to 0.214)mg/l, K (0.037 to 0.089)mg/l, Ca (0.702 to 2.140)mg/l, Mg (0.221 to 0.941)mg/l, Cl (35.5 to 88.6)mg/l, P (0.254 to 0.651)mg/l, NH4N (0.231 to 0.774)mg/l, NO2 (0.015 to 0.077)mg/l, NO3 (0.021 to 0.781)mg/l, SO4 (0.074 to 0.981)mg/l, Fe (0.101 to 2.581), Mn (0.033 to 0.633)mg/l, Zn (0.061 to 0.901)mg/l, Cu (0.027 to 0.378)mg/l, Cr (0.015 to 0.101)mg/l, Cd (0.005 to 0.033)mg/l, Ni (0.003 to 0.033)mg/l. Pb (0.01 to 0.071)mg/l, V (0.001 to 0.01)mg/l, no THC was detected and Coliform (0 × 103)cfu/ml. The analyzed parameters were generally within WHO permissible limits. The result showed that water quality in this area is generally not polluted, and is safe for drinking and for other domestic purposes with only very little water treatment required especially in location 6 (River Nkpuru) where some of the analyzed parameters were slightly above the standards set by the World Health Organization (WHO).
