Data Analysis Tools

This focuses on how we use groundwater age to predict changes in nitrate concentrations over time. Typically, deep public supply wells draw from deeper parts of the aquifer where water is decades, centuries, or even millenia old.

The USGS first identified uranium as a potential issue in California's groundwater during studies conducted in the Modesto area funded by the USGS National Water Quality Assessment Program. Subsequently, the GAMA program undertook a broader analysis of uranium concentrations across the State.

Arsenic is known to be a problem in groundwater used for drinking water supplies in the San Joaquin Valley. About 10% of the are of groundwater resources used for public supply contain more than the USEPA MCL of 10 µg/L. Most public-supply and domestic wells currently yield groundwater with arsenic levels below 3 µg/L and do not exhibit trends in concentration.

This water-use data-gap analysis analyzed the differences between the current state of the Nation's water-use data and the data needed to achieve the long-term goals of the USGS Water Availability and Use Science Program.

The purpose of this database is to provide a publicly available and spatially referenced national dataset of natural gas geochemistry.

This website provides visualizations of population change for North American birds using data from the North American Breeding Bird Survey (BBS). The BBS is analyzed for a "core" area (contiguous United States and southern Canada, results available from 1966-present), and for an "expanded" survey area (including portions of Alaska and northern Canada with results from 1993-present).