This document discusses the principles, purpose, objectives and procedural steps of environmental impact assessment (EIA). It begins by introducing the principle of sustainable development and defining EIA. It then discusses the National Environmental Policy Act which requires EIA for proposed actions. The purpose of an EIA report is to estimate environmental effects, present the report to authorities, and allow for improvements. The objectives are to ensure environmental effects of projects are considered before approval and to encourage relevant procedures. The procedural steps outlined are screening, scoping, impact prediction, mitigation, reporting, review, decision making, monitoring and post-development audit.