GAMA: Groundwater Ambient Monitoring & Assessment Program
Domestic Well ProjectQuestions About the Water in Your Well?
Current News
None at this time.
Project Description
The State Water Board GAMA Program’s Domestic Well Project (Domestic Well Project) samples for various chemicals commonly found in well water.
Domestic wells are for private use and consumption, typically for single family homeowners. The water quality information is provided to the well owners and users. The names and addresses of the well owners are maintained as confidential information.
Currently, the quality of domestic well water in California is largely unknown. Domestic well sampling programs in other states have detected chemical contaminants, such as nitrate, coliform bacteria and MTBE in wells.
The Domestic Well Project provides a public education component to aid the public in understanding water quality issues affecting domestic water wells. The Domestic Well Project has sampled in several focus areas of the state.
These focus areas have been chosen based upon existing knowledge of water quality and land use, in coordination with local environmental agencies. The State Water Board incurs the costs of sampling and analysis.
- Statewide Summary
- Tulare County (2006)
- Tehama County (2005)
- El Dorado County (2003 and 2004)
- Yuba County (2002)
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Tulare County Study Area (2006)
Description: During May through June 2006, Domestic Well Project staff sampled approximately 180 private domestic supply wells in Tulare County.
Table
Maps
- Sample Locations with Results Above MCL
- Sample Locations with Nitrate Results
- Sample Locations with Coliform and/or Nitrate
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Tehama County Study Area (2005)
Description: During April through June 2005, Domestic Well Project staff sampled approximately 220 private domestic supply wells in Tehama County.
Table
- Sample Results above DHS MCL (coming soon)
Maps
- Sample Locations with Nitrate Results
- Sample Locations with Coliform
- Sample locations with As detections
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El Dorado County Study Area (2003 and 2004)
Description: During February through May 2003 and April through June 2004, Domestic Well Project staff sampled approximately 400 domestic wells in Western El Dorado County.
- Draft El Dorado County Data Summary Report (includes text, maps, summary tables, and figures)
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Description: During April through June 2002, Domestic Well Project staff sampled 119 wells in Yuba County. Domestic Well Project staff provided the sample testing results and an explanation of the data, to the well owners.
Table
- Sample Results above DHS MCL (coming soon)
Maps
- Sample Locations with Results Above MCL (coming soon)
- Sample Locations with Nitrate Results (coming soon)
- Sample Locations with Coliform

