Environmental Forensics, 12:92–97, 2011 Copyright C  Taylor & Francis Group, LLC ISSN: 1527–5922 print / 1527–5930 online DOI: 10.1080/15275922.2011.547437 Contamination of Drinking Water Due to Coal-Based Thermal Power Plants in India Prashant Agrawal, 1 Anugya Mittal, 1 Rajiv Prakash, 2 Manoj Kumar, 1 and S. K. Tripathi 1 1 Instituteof Medical Sciences, Banaras Hindu University, Varanasi, India 2 Institute of Technology, Banaras Hindu University, Varanasi, India This study assessed the impact of an Anpara and Renusgar coal-based thermal power plants on drinking water sources. In this work, the concentration of trace metals such as Pb, Cd, Ni, and As in groundwater samples obtained from hand pumps located near these power plants were measured. The concentration levels of all the studied heavy metals in groundwater were found to be higher than the maximum acceptable limits of World Health Organization for drinking water. Keywords: power plant, groundwater, metals, contamination In recent years, cases related to surface and groundwater pol- lution have increased dramatically; therefore, investigation on this subject is gaining considerable interest. The water demand is mainly supplied by surface water and groundwater resources. Surface and groundwater sources are known to contain trace elements, some of which have been widely implicated in human health and disease (Demirak et al., 2005). Contamination of groundwater sources occurs in various stages. Discharge of contaminants from a polluting source, leaching of biological, chemical, or physical contaminants from soil to groundwater sources, are the main causes of groundwater contamination. The waste disposal from the use of fossil fuel as energy resource is one of the major sources of environmen- tal pollution in industrialized areas. The solid wastes produced by coal-based power plants mainly comprise slag, bottom ash, and fly ash. Due to its relatively small particle size and hence large surface area, fly ash has a greater tendency to adsorb trace elements on its surface; those elements are transferred from coal to fly ash during combustion (Klein et al., 1975; Campbell et al., 1978; Demirak et al., 2005). As a consequence of the substantial consumption of coal in thermal power plants (TTPs), a significant quantity and variety of trace elements, some of them potentially toxic, are transferred (after the combustion) to the surrounding environment through different pathways (Goetz and Sabbioni, 1981; Goetz and others 1981a; 1981b; Sabbioni and Goetz, 1983; Benson et al., 1994; Chow, et al., 1994; Plant et al., 1998). The major part of fly ash is disposed of in unmanaged landfills or lagoons, which serve as a major source of environmental pollution in the area through Address correspondence to Prashant Agrawal, Department of Forensic Medicine, Institute of Medical Sciences, Banaras Hindu Uni- versity, Varanasi, India. E-mail: prashantagrawala@gmail.com fly ash erosion and leachate generation (Gupta et al., 2002). Trace elements present on the surface of fly ash particles are readily leached from the soil and contaminate the groundwater resources (Shi and Sengupta, 1995; Fytianos and Tsaniklidi, 1998; Theis and Gardner, 1990; Theis et al., 1978; Carlson and Adriano, 1993). In this study, trace metal contents in the groundwater samples (drinking water) obtained from different locations surrounding Anpara and Renusagar TTPs were measured. This study is con- cerned with environmental effects on groundwater due to fly ash produced from these TTPs. The major aims of this study are (1) to determine the concentrations of trace elements in groundwa- ter, and (2) to compare the measured concentrations of the trace elements with drinking water quality standards of the World Health Organization. Materials and Methods Sonbhadra is one of the largest districts of Uttar Pradesh, India situated at longitudes 82.72 and 83.33 and latitudes 23.52 and 25.32. According to the 2001 census (Census of India, 2001), the district has an area of 6788 km 2 and a population of 1,463,468. The present study is limited to area surrounding coal-based Anpara and Renusagar TTPs and covered a diameter of 16 km around these TTPs. The population around both these power plants mainly consists of employees and workers of organiza- tions dealing with the power or coal industry. In addition to this population, staff members of various government agencies, such as hospitals and schools, and businessmen are major part of residents. Three cement factories, one aluminum plant, one carbon plant and one chemical factory are also situated in Sonebhadra district and are approximately 80 km away from studied 92