The Institute of the Environment and Sustainability at Western Michigan University recommends the following governmental data sites.
Energy Information Administration
Published by the U.S. Department of Energy, the Energy Information Administration site maintains a vast database of energy production and consumption figures from all energy sectors, on a domestic and global basis.
Surf Your Watershed
Published by the U.S. Environmental Protection Agency, Surf Your Watershed is a searchable database of information for most watersheds in the United States, including reported water quality and hydrologic data.
National Atmospheric Deposition Program
The National Atmospheric Deposition Program organizes and publishes data and maps of atmospheric pollution in the United States. Types of pollution covered by the NADP database include rainfall, major dissolved ions, pH, and pollutant NOx and SOx concentrations. The NADP is a cooperative research-support program of the US Department of Agriculture and state cooperative research and extension services.