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Federal
Map of Arsenic concentrations in groundwater of the United States
Department of the Interior —
The map graphic image at https://www.sciencebase.gov/catalog/file/get/63140561d34e36012efa2b7f?name=arsenic_map.png illustrates arsenic values, in micrograms per... -
Federal
Drainage Basins Used for Assessing Trends in Concentration of Pesticides in Streams of the United States, 1992-2010
Department of the Interior —
This dataset consists of drainage basin boundaries for 212 U.S. Geological Survey (USGS) stream sites sampled in the National Water-Quality Assessment (NAWQA)...