Groundwater Ambient Monitoring & Assessment (GAMA)
The Groundwater Ambient Monitoring and Assessment Program’s Priority Basin Project (GAMA-PBP) was established by the California State Water Resources Control Board (SWRCB) in response to the Ground-Water Quality Monitoring Act of 2001 (Sections 10780-10782.3 of the California Water Code). The USGS is the technical lead for the GAMA-PBP and between 2004-2012 focused on characterizing the quality of groundwater used by public water supply systems statewide. Beginning in 2012, the focus shifted to assessing groundwater quality tapped by domestic wells and small community-supply systems while continuing a long-term trend monitoring effort.
Public Supply Well Inorganic Constituent Data and Trends Map
This interactive web map plots trends in groundwater quality (inorganic constituents) at public supply wells from 1974-2019 using data from USGS GAMA-PBP and monitoring data reported to the California State Water Resources Control Board Division of Drinking Water.
GAMA-PBP Groundwater Quality Assessment and Trends Data
This interactive webmap plots and enables downloads of water-quality data from domestic and public-supply wells sampled by the USGS for GAMA-PBP. Data can be viewed and downloaded for study type, constituent groups, individual sites, and grid cells.
Modeling the dynamic penetration depth of post-1950s water in unconfined aquifers using environmental tracers: Central Valley, California
Effects of Imported Recharge on Fluoride Trends in Groundwater Used for Public Supply in California
Increased Pumping in California's Central Valley During Drought Worsens Groundwater Quality
See the new GAMA-PBP web application! Learn more about the program, see new science highlights, explore study areas using a map interface, and download publications and data.
The Groundwater Ambient Monitoring and Assessment Program’s Priority Basin Project (GAMA-PBP) was established by the California State Water Resources Control Board (SWRCB) in response to the Ground-Water Quality Monitoring Act of 2001 (Sections 10780-10782.3 of the California Water Code). The USGS is the technical lead for the GAMA-PBP and between 2004-2012 focused on characterizing the quality of groundwater used by public water supply systems statewide. Beginning in 2012, the focus shifted to assessing groundwater quality tapped by domestic wells and small community-supply systems while continuing a long-term trend monitoring effort.
Public Supply Well Inorganic Constituent Data and Trends Map
This interactive web map plots trends in groundwater quality (inorganic constituents) at public supply wells from 1974-2019 using data from USGS GAMA-PBP and monitoring data reported to the California State Water Resources Control Board Division of Drinking Water.
GAMA-PBP Groundwater Quality Assessment and Trends Data
This interactive webmap plots and enables downloads of water-quality data from domestic and public-supply wells sampled by the USGS for GAMA-PBP. Data can be viewed and downloaded for study type, constituent groups, individual sites, and grid cells.
Modeling the dynamic penetration depth of post-1950s water in unconfined aquifers using environmental tracers: Central Valley, California
Effects of Imported Recharge on Fluoride Trends in Groundwater Used for Public Supply in California
Increased Pumping in California's Central Valley During Drought Worsens Groundwater Quality
See the new GAMA-PBP web application! Learn more about the program, see new science highlights, explore study areas using a map interface, and download publications and data.