Welcome to the State Water Resources Control Board Welcome to the California Environmental Protection Agency
Governor's Website Visit the Water Board Members Page
My Water Quality
Performance Report

GAMA – Groundwater Ambient Monitoring & Assessment Program

The GAMA Program is California's comprehensive groundwater quality monitoring program.

GAMA collects data by testing the untreated, raw water in different types of wells for naturally-occurring and man-made chemicals. GAMA compiles these test results with existing groundwater quality data from several agencies into a publicly-accessible internet database, GeoTracker GAMA.

GAMA - Providing a Better Understanding of California’s Groundwater

Over 95 percent of the 38 million California residents get their drinking water from a public or municipal source – these supplies are typically treated to ensure that the water is safe to drink.

However, up to 2 million California residents are served either by the estimated 250,000 to 600,000 private domestic wells or by water systems serving fewer than 15 service connections. The California Department of Public Health (CDPH) does not regulate the quality of water from either of these sources. Private domestic well owners are responsible for maintaining their well and are encouraged to test their well water quality. Please visit Concerned About Your Well’s Water Quality for more information.

Californians served by a public water system should also be concerned about groundwater quality since nearly nine out of ten systems rely on groundwater for at least a portion of their supply. Contaminated groundwater results in treatment, well closures, or new well construction, which increases costs for consumers.

A large portion of California is in a semi-arid climate and as a result more reliant on groundwater. Having clean water is critical to sustain society and the environment, as well as business, industry, and agriculture. Comprehensively monitoring groundwater is critical in managing our water resources.

GAMA Program Background

The GAMA Program was created by the State Water Board in 2000. It was later expanded by Assembly Bill 599 – the Groundwater Quality Monitoring Act of 2001. Major groundwater supply basins are a specific focus of the GAMA program. The legislatively mandated program (AB 599) is funded by Proposition 50 and from special fund fees.

The main goals of GAMA are:

  • to improve statewide groundwater monitoring
  • to increase the availability of groundwater quality information to the public.

There are four active GAMA projects:

Visit the links on this page to learn more about groundwater quality.

Fact Sheets

Recent Reports to Legislature

PAC Meeting - April 30, 2013
Summary and Action Items

PAC Meeting - April 20, 2012

Where Does My Water
Come From?

More Information on Water Quality in your Area

Hydrogeologically Vulnerable Areas
Map and Table