Environmental Impact Statement

Once an environmental assessment has been completed, and federal projects have filed an approved EIS, the project or policy may proceed. When the development is completed, the associated environmental stresses begin to affect species, ecosystems, and socioeconomic systems. The actual effects of a project must then be monitored to ensure compliance with environmental regulations, to observe and mitigate any unforeseen consequences, and to compare real damages to predicted ones. Monitoring might include measuring levels of chemical emissions into the air, water, or soil, observing the response of plants and animals at the site, or surveying the health of employees and nearby residents of the site. Socioeconomic impacts, like increased traffic congestion, or water availability for surrounding agricultural and municipal interests, are also including in appropriate monitoring schemes. Predictions set out in the pre-development environmental impact assessment usually determine the structure of monitoring programs. Monitoring programs must be flexible and adaptive, because "surprises," or unpredicted environmental changes, often occur. In this sense, environmental impact assessment is an ongoing process that extends over the lifetime of a development.