660 Mine water quality and its management in Indian metalliferrous mines R.K. Tiwary, D.B. Singh, B.K. Tewary Central Mining Research Institute, Barwa Road, Dhanbad - 826 001. India, Fax : (0326) 202093 e-mail: tiwary_rk@yahoo.com Abstract: Surface mine development and underground mine working below piezometric level invariably change the hydraulic gradient, thus affecting ground and surface water flow and water quality. The presence of water in mining sites creates a range of operational and stability problems and requires a drainage plan to avoid slope stability problem, oxidation of metallic sulfides and corrosion of mining machinery and equipment. The quality of the drainage water depends on a series of geological, hydrological and mining factors which vary significantly from mine to mine. Water quality impacts are primarily due to the alteration of equilibrium in the underground water regime and the formation of acid mine water due to occurrence of pyritic ore impurities with parent metallic ores. In India there are approximately 9906 mining leases spread over an area of 7453 sq. kilometres covering 55 minerals other than fuel. 35% of the valid lease area are covered by iron and limestone. Major states having metal mining activities are Rajasthan (25%), Karnataka (15%), Orissa (14%) and Bihar (11%), covering 65% of the lease area. Predominantly copper, iron, lead zinc, chromite and manganese are extracted in India. The extraction of the metals is done by both opencast and underground mining methods. Large volumes of mine water are discharged in underground operations while minor volumes are discharged in hill mining. Some mine water, in the case of lead zinc, copper, manganese and chromite is slightly acidic and contains toxic heavy metals. In some cases, mine water is treated with lime to reduce acidity and finally discharged to the tailing dam for further settlement of suspended solids. Environmental legislation have been framed to control the discharge quality and appropriate guidelines have also been suggested for their treatment to avoid contamination of surrounding land and water resources. The paper discusses the detail study of mine water quality in metalliferrous mines of copper, lead zinc, manganese, iron and chromite and their treatment and disposal system for water quality management. 1 INTRODUCTION In the process of development, mining is one of the core industries contributing, knowingly or unknowingly, towards the deterioration of the environment in terms of air pollution, water pollution and land degradation. To achieve sustainable development, an environmental protection element should be introduced at the planning stage of the mining project itself. India is endowed with a wide range of mineral reservoirs. In the country there are approximately 9906 mining leases spread over an area of 7453 square kilometres covering 55 minerals other than fuel. 35% of valid lease area are covered by Iron and Limestone. These minerals are extracted from over 3200 operating mines out of which 30 minerals are produced exclusively through