Study of quaternary aquifers in Ganga Plain, India: focus on groundwater salinity, fluoride and fluorosis.

In marginal and central alluvial plains (Ganga Plain) of India, the inland salinity is continuously increasing, canal network and arid to semi-arid climatic conditions that led to excessive evapotranspiration concentrates the salt in soil and thereby escalating the groundwater salinity. In Mat Tahsil, Mathura district (Ganga Plain) study on shallow and deep aquifer salinity and fluoride was carried out in August 2001 and 2004. Groundwater salinity in some parts is more then 4000 microOmega(-1)/cm. This region is severely affected by endemic fluorosis due to consumption of fluoride-contaminated water. Analysis of F(-), Na(+), K(+), Cl(-) and HCO(3)(-) was carried out at 30 sites of dugwells and borewells. Result shows that there is a variation and continuous escalation in the groundwater salinity and fluoride concentration in deep and shallow aquifers on the basis of analysis. Classification of salinity levels was carried out in 2001 and 2004. The deep aquifers (borewells) are found more saline as compare to the shallow aquifers (dugwells) while F(-), Na(+), K(+), Cl(-) and HCO(3)(-) shows high concentration in shallow aquifers. The fluoride concentration in the groundwater of these villages showed values from 0.1 to 2.5mg/l, severe enough to cause dental and skeletal fluorosis among the inhabitants, especially children of these villages. One of the major effects of inland salinity in this region is from saline groundwater, which is reaching the land surface and causing soil salinisations and water logging in the NE and SE parts of Mat block.