Abstract:
Increased population and increasing demands for food in the Indo-Gangetic plain are
likely to exert pressure on fresh water due to rise in demand for drinking and irrigation water. The
study focuses on Bhojpur district, Bihar located in the central Ganga basin, to assess the
groundwater quality for drinking and irrigation purpose and discuss the issues and challenges.
Groundwater is mostly utilized in the study area for drinking and irrigation purposes (major crops
sown in the area are rice and wheat). There were around 45 groundwater samples collected across
the study region in the pre-monsoon season (year 2019). The chemical analytical results show that
Ca2+, Mg2+ and HCO3− ions are present in abundance in groundwater and governing the
groundwater chemistry. Further analysis shows that 66%, 69% and 84% of the samples exceeded
the acceptable limit of arsenic (As), Fe and Mn respectively and other trace metals (Cu, Zn, Pb, Cd)
are within the permissible limit of drinking water as prescribed by Bureau of Indian Standard for
drinking water. Generally, high as concentration has been found in the aquifer (depth ranges from
20 to 40 m below ground surface) located in proximity of river Ganga. For assessing the irrigation
water quality, sodium adsorption ratio (SAR) values, residual sodium carbonate (RSC), Na%,
permeability index (PI) and calcium alteration index (CAI) were calculated and found that almost
all the samples are found to be in good to excellent category for irrigation purposes. The
groundwater facie has been classified into Ca-Mg-HCO3 type.
