Tens of millions of people in south and southeast Asia routinely consume ground water that has unsafe arsenic levels. Using hydrologic and (bio)geochemical measurements, the researchers show that on the minimally disturbed Mekong delta of Cambodia, arsenic is released from near-surface, river-derived sediments and transported, on a centennial timescale, through the underlying aquifer back to the river.

South Asia's well-water is widely polluted with arsenic, but no one has located the source. A study on the Mekong River finds that contamination begins in pond sediments, and is spread by groundwater flow to wells.

Ground water samples from 83 villages in Honnali taluk of Davangere district were analyzed for their suitability for irrigation purpose with special reference to presence of fluoride content. Ground water in the study area was classified according to sodium adsorption ratio and electrical conductivity.

The ground water samples collected from different tehsils of Ujjain district were analysed in the laboratory for electrical conductivity (EC), pH, cations (Na+, K+, Ca2+ and Mg2+) and anions (CO32-, HCO3-, Cl- and SO42-). The ground water quality map of the district was generated using ERDAS-IMAGINE 8.7 software showing different categories.

Groundwater quality data on physico-chemical, bacteriological and heavy metal concentrations in three cities (Faridabad, Allahabad and Varanasi) in Ganga-Yamuna basin was subjected to multivariate analysis using SPSS. The factors extracted showed high loading (>0.3) of various parameters, such Cl, conductivity, TDS, hardness, Na, Mg and SO4 indicating contamination due to leaching of pollutants.