Evaluation of hydrochemical characteristics and flow directions of groundwater quality in Udi Local Government Area Enugu State, Nigeria

A hydrogeological study was conducted at the Udi Local Government Area in south-eastern region of Nigeria to examine the hydrochemical constituent of groundwater and determine the quality for drinking and agricultural purposes. Results show that groundwater in the area is slightly acidic to slightly basic, soft and potable, when compared with the World Health Organisation standards for drinking water, and is suitable for agricultural purposes. The groundwater flow direction was determined to establish the implications of pollution from any water contamination. Twenty-one groundwater samples from existing boreholes were collected and analysed for various physicochemical parameters using standard field and laboratory techniques. Distribution of major ions was plotted on a Trilinear Piper diagram. Ajali Sandstone, known as major aquiferous layer in the area, outcrops predominately in sandy bed with medium to coarse-grained sediments. The aquifers are unconfined, semi-confined and with hydraulic conductivity values ranging from 9.0 × 10−2 to 8.5 × 10−2 m/day indicating medium transmissivity of groundwater in some areas and a flow net south to northward groundwater flow towards the coast. This explains why the aquifer does not appear to be very permeable and only provides a medium yield of good quality water in some regions of the study area.