Chemistry and discharge characteristics of Odukpani junction springs, Calabar Flank, south-eastern Nigeria

A 6-month study spanning the rainy and dry seasons was conducted on Odukpani Junction springs (Nigeria) to assess the variation in discharge and physico-chemical parameters. The study also evaluated the impact of geology and indiscriminate disposal of wastes on spring water quality. The results indicate a poor correlation between discharge (Q) and amount of rainfall (R). This is attributed to the distance of the meteorological station and the sampled localities, thus eliminating micro rainfall data. However, Q increased with an increase in R. The variation of ions with time was not large; however, concentrations were higher during the rainy season in most cases. Three major chemical facies (Ca-HCO₃, Ca-SO₄, K-HCO₃) identified show major relationship with lithology. Multiple regression equations have been developed to predict the total dissolved solids (TDS), electrical conductivity (EC) and discharge (Q). The level of nitrate is high (9-43 mg/l) compared with the World Health Organisation (WHO) limits of 10.0 mg/l. This is attributed to the indiscriminate dumping of domestic, human and animal wastes. Other parameters determined are within the limits acceptable for potable water by the Nigerian Federal Environmental Protection Agency (NFEPA) and WHO.