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Federal
USGS Water-Quality Data for the Nation - National Water Information System (NWIS) 123 recent views
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
Map of Arsenic concentrations in groundwater of the United States 48 recent views
Department of the Interior —
The map graphic image at https://water.usgs.gov/GIS/browse/arsenic_map.png illustrates arsenic values, in micrograms per liter, for groundwater samples from about...