HYDROGEOCHEMISTRY AND GROUNDWATER QUALITY OF MICHIKA AREA NE NIGERIA

Gabriel Ike Obiefuna, Peter Hassan Sini and AbubakarMaunde

Department of Geology

Modibbo Adama University of Technology, Yola, Nigeria

ABSTRACT

The aim of this study is to assess the quality of the shallow groundwater quality of Michika area of Nigeria for irrigation and domestic purposes. Geological mapping revealed the area is underlain by granitic rocks of Pan-African age. These rocks are grouped into three types: coarse grained biotite granites, coarse porphyritic granites and medium grained granites which are intruded by the new basaltic rocks of Tertiary age. Forty water samples collected from wells tapping shallow aquifer were used. Chemical analyses were performed in the laboratory employing standard methods viz Atomic Adsorption Spectrophotometry for cations and conventional titration for anions. In addition ions in milligram per liter were converted to mill equivalent per liter and anions balanced against cations as a control check of the reliability of the analyzed results. The analyzed chemical parameters were interpreted and the result revealed that most of the samples are slightly acidic to alkaline, largely soft with fairly low to moderate concentrations of dissolved solids that fall within the international limits for domestic purposes. However, the concentration of iron and nitrate in less than 1% and 25% respectively is higher than the maximum acceptable concentration of 0.3 mg/l and 10 mg/l respectively and should be treated before use. The hydro geochemistry of the study area indicate two water type that is Ca-mg-HC0₃ and Na-C0₃ for both hand dug well and boreholes Thus most of the samples will neither cause salinity hazards nor have an adverse effect on the soil properties and are mostly suitable for domestic and irrigation purposes.

Keywords; groundwater quality, geological mapping, chemical analyses, Michika Area, NE Nigeria