V. RAJANI
Abstract
There is growing concern throughout India about the contamination of groundwater as a result of geogenic and human activities. In India, groundwater resources are being utilized for drinking, irrigation and industrial purposes. The groundwater is estimated to provide about 80 percent of water for domestic use in rural areas and about 50 percent of water for urban and industrial areas. With the rapid growth in population, urbanization, industrialization and other developmental activities, groundwater resources have become vulnerable to depletion and quality degradation. The causes of groundwater contamination include use, spillage, or disposal of pesticides, fertilizers, petroleum hydrocarbons, industrial chemicals, and waste products. The contamination can also result from geologic sources and changes in the existing land use. Kerala is strongly dependent upon groundwater and has considerable value both for its economic and social uses (i.e. drinking water, water supply system, agriculture, industry, and recreation), and for its role in maintaining a range of ecosystems at the surface and below ground. The contamination of groundwater can have adverse effects on these uses, ultimately leading, as water quality deteriorates, to the groundwater being unable to support or maintain these beneficial uses. In most cases this degradation is irreversible. Remediation is very expensive and is often unsuccessful. Consequently, adequate protection of groundwater quality must be a primary aim. Groundwater and surface water are often closely linked, and changes to quality or quantity in one resource frequently creates an impact on the other. Groundwater contributes to streams, lakes and wetlands and is particularly significant in maintaining these surface water ecosystems in dry periods. Furthermore, surface water quality can affect groundwater quality through seepage and where surface water directly enters into groundwater. Protection of surface water quality is often considered to be of paramount importance because impacts of contamination or poor water quality are readily observed. Additionally, there is a need for a greater awareness of groundwater, its key role in supporting a range of economic, social and environmental values, its significance in the hydrological cycle and the need to protect these valuable but invisible resources.