Environmental Impact Assessment
Environmental impact assessment (EIA) is a tool that seeks to ensure sustainable development through the evaluation of those impacts arising from a major activity (policy, plan, program, or project) that are likely to have significant environmental effects. It is anticipatory, participatory, and systematic in nature and relies on multidisciplinary input (Glasson et al. 1994). 

The phrase Environmental Impact Assessment comes from Sec. 102 (2) of the National Environmental Policy Act (NEPA), 1969, USA. Some rudiments of EIA are implicit even in early examples of environmental legislation. Napoleon in 1910 issued a decree which divided noxious occupations into categories: those which must be far removed from habitations, those which may be permitted on the outskirts of towns, and those which can be tolerated even close to habitations, having regard to the importance of the work and the importance of the surrounding dwellings. Now the EIA has become a requirement in more than 100 countries (Canter 1996). In many European countries, it came into vogue with the introduction of the concept of sustainable development after the World Commission of Environment in 1987. In India, though EIA came into existence around 1978-79 , it was made mandatory only in 1994.
Following sections will give more detailed information on EIA :

Legal Provisions of the Environmental Impact Assessment
Administrative Arrangements for Implementing Environmental Impact Assessment
The EIA Procedure - Phases involved for getting an EIA Clearance
Guidelines for obtaining Environmental Impact Assessment Clearance
Role of different actors during the Environmental Impact Assessment Process
Projects which are subject to Environmental Impact Assessment
Public Participation in Environmental Impact Assessment
Useful links on Environmental Impact Assessment
http://coe.mse.ac.in 2003-09. Madras School of Economics - Systems Department