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Federal
USGS Water-Quality Data for the Nation - National Water Information System (NWIS)
Department of the Interior —
The USGS compiles online access to water-resources data collected at approximately 1.5 million sites in all 50 States, the District of Columbia, Puerto Rico, the... -
Federal
Safe Drinking Water Information System (SDWIS)
U.S. Environmental Protection Agency —
The Safe Drinking Water Information System (SDWIS) contains information about public water systems and their violations of EPA's drinking water regulations. -
Federal
1/3rd arc-second Digital Elevation Models (DEMs) - USGS National Map 3DEP Downloadable Data Collection NGDA
Department of the Interior —
This is a tiled collection of the 3D Elevation Program (3DEP) and is 1/3 arc-second (approximately 10 m) resolution. The 3DEP data holdings serve as the elevation... -
Federal
ICLUS v1.3 Estimated Percent Impervious Surface for the Conterminous USA
U.S. Environmental Protection Agency —
Climate and land-use change are major components of global environmental change with feedbacks between these components. The consequences of these interactions show... -
Federal
Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: STATSGO Soil Characteristics
Department of the Interior —
This data set represents estimated soil variables compiled for every catchment of NHDPlus for the conterminous United States. The variables included are cation...