Hydrogeochemical assessment of groundwater in Kaltungo and Environs, northeastern Nigeria.

Abstract

Analytical results indicate that groundwater samples from kaltungo and environs are polluted due to high concentrations of iron, fluoride, nitrate, and coliform bacteria. Iron concentrations range from 1.9 mg/l to 4.8 mg/l, fluoride values range from 0.6 mg/l to 1.9 mg/l, and nitrate concentrations range from 46.8 mg/l to 164 mg/l while coliform number counts range from nil to 80 number counts. The results further reveal that the water is generally good for agricultural uses. The SAR values range from 0.003 meq/l to 0.38 meq/l, RSC values range from -6.20 meq/l to 4.97 meq/l, EC values vary from 160 1S/cm to 790 1S/cm, and TDS ranges from 80 mg/l to 400.5 mg/l. However, the water may not be suitable for some industries due to high concentrations of iron, bicarbonate, and total hardness. Bicarbonate values range from 206 mg/l to 612 mg/l, and total hardness range from 73.4 mg/l to 163.7 mg/l. Piper trilinear plots classified the water into Ca-(Mg)-HCO₃ which belongs to the normal alkaline fresh water type. Based on Mg²⁺/Ca²⁺ ratio, about 39% of water samples reveal water from silicate aquifer. Plots of logTDS against Na+/(Na+ + Ca²⁺) reveal that the groundwater chemistry is influenced by evaporation, weathering induced dissolution, and dilution effects. The water would require treatment for human consumption and for industrial applications. It is recommended that regular groundwater quality monitoring will ensure groundwater quality protection and conservation.

KEY WORDS: Groundwater chemistry, silicate aquifer, alkaline fresh water, kaltungo area, polluted.