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The metal pollution in water and sediment of the River Hindon in western Uttar Pradesh (India) was assessed for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. The metal concentrations in water showed wide temporal variation compared with bed sediment because of variability in water discharge and variations in suspended solid loadings. Metal concentrations in bed sediments provided a better evaluation of the degree and the extent of contamination in the aquatic environment, Santagarh and Atali being the most polluted sites of the river. The ratio of heavy metals to conservative elements (Fe, Al, etc.) may reveal the geochemical imbalances due to the elevated metal concentrations normally attributed to anthropogenic sources. Metal/A1 ratios for the bed sediments of the river Hindon were used to determine the relative mobility and general trend of relative mobility occurred Fe > Mn > Zn > Cr > Ni > Pb > Cu > Cd.

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The impact of untreated sewage disposal and sewage irrigation practice around Roorkee, Uttarakhand, India, on groundwater contamination is studied using surface geoelectrical techniques. Electrical resistivity tomography (ERT) and transient electromagnetic (TEM) soundings data were recorded in and around a sewage‐irrigated area in Saliyar and Khanjarpur and a remote site where groundwater contamination due to sewage was not expected. The sewage is mainly composed of domestic and municipal waste. Lithology data was used for correlating the resistivity values, which were derived from 2D inversion of resistivity and 1D Occam inversion of TEM data, with the subsurface formation. These two methods were used jointly to increase the reliability of the results in mapping of ground‐water contamination. It was thus observed that the sewage pollutants, infiltrated through the soil, reach the shallow unconfined aquifer in and around the polluted area, up to a limited distance from the existent waste disposal sites. The present study suggests that the groundwater present in the shallow unconfined aquifer (<10 m depth) close to waste disposal sites is contaminated. It was noticed that the decrease in the resistivity of a shallow unconfined aquifer is up to 50% in comparison with that of the shallow unconfined aquifer at a remote site located about 20 km north‐west of the disposal sites. The extent of the polluted aquifer zone was delineated by comparing its resistivity with that of the same aquifer at a point away from the disposal sites. Thus, the extent of groundwater pollution and relative direction of its flow were also determined qualitatively.

The river Hindon is one of the important tributaries of river Yamuna in western Uttar Pradesh (India) and carries pollution loads from various municipal and industrial units and surrounding agricultural areas. The main sources of pollution in the river include municipal wastes from Saharanpur, Muzaffarnagar and Ghaziabad urban areas and industrial effluents of sugar, pulp and paper, distilleries and other miscellaneous industries through tributaries as well as direct inputs. In this paper, chemical mass balance approach has been used to assess the contribution from non-point sources of pollution to the river. The river system has been divided into three stretches depending on the land use pattern. The contribution of point sources in the upper and lower stretches are 95 and 81% respectively of the total flow of the river while there is no point source input in the middle stretch. Mass balance calculations indicate that contribution of nitrate and phosphate from non-point sources amounts to 15.5 and 6.9% in the upper stretch and 13.1 and 16.6% in the lower stretch respectively. Observed differences in the load along the river may be attributed to uncharacterized sources of pollution due to agricultural activities, remobilization from or entrainment of contaminated bottom sediments, ground water contribution or a combination of these sources.