Groundwater provides more than 40 percent of California's drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. The Upper Santa Ana Watershed is one of the study units being evaluated.
Additional publication details
USGS Numbered Series
Groundwater quality in the Upper Santa Ana Watershed study unit, California