Groundwater Ambient Monitoring & Assessment (GAMA)


What is GAMA?

The Groundwater Ambient Monitoring and Assessment Program (GAMA) is a statewide, comprehensive assessment of groundwater quality designed to help better understand and identify risks to groundwater resources. GAMA is being implemented by the California Water Board.

The USGS is the technical lead for the Priority Basin Project (PBP), one of four GAMA components. The USGS is sampling groundwater at many locations across California in order to characterize its constituents and identify trends in groundwater quality.

The results of these tests will provide information for water agencies to address a variety of issues ranging in scale from local-water supply to statewide resource management.

Two aquifer depth zones are being studied: Deep aquifers and Shallow aquifers.

Where has GAMA been?

Select a Province to navigate to study unit. Klamath Mountains Modoc Plateau and Cascades Northern Coast Ranges Central Valley Sierra Nevada Southern Coast Ranges Transverse and Selected Peninsular Range San Diego Basin and Range Desert

Water Quality Results

Explore and download groundwater-quality results with the new webmap!

Screen shot of the groundwater quality results mapper

This interactive webmap plots water-quality data from domestic and public-supply wells sampled by the USGS for the California GAMA Priority Basin Project, and allows users to download datasets.

Go to the Webmap

Domestic Well Sampling

Well Owners Needed!

The Groundwater Ambient Monitoring & Assessment Priority Basin Project (GAMA-PBP) is conducting water-quality assessments of shallow aquifers, the groundwater resources typically used for private domestic and small system drinking-water supplies. We need wells to sample, and volunteer well owners who participate in the study will receive a free chemical analysis of their well water.


See if we have a study near you!