There are as many as 2 million water wells in California, with approximately 10,000 to 15,000 new wells constructed each year. They range from hand-dug, shallow wells to carefully designed large-production wells drilled to great depths.
Under the California Water Code Sections 13700 to 13806, we have the responsibility for developing well standards. We maintain these standards to protect groundwater quality. California Well Standards, published as DWR Bulletin 74, represent minimum standards for well construction, alteration, and destruction to protect groundwater. In California, cities, counties, and water agencies have regulatory authority over wells and can adopt local well ordinances that meet or exceed the statewide Well Standards.
The State Water Resources Control Board has authority to adopt DWR well standards into a statewide model well ordinance. Cities, counties, or water agencies have authority to adopt a local ordinance that meets or exceeds DWR well standards. If no local ordinance is adopted, the model well ordinance takes effect in that jurisdiction. Well ordinances are enforced by local enforcing agencies (see the Permitting Agencies tab for more information).
- 1. Bulletin 74-2: Recommended Minimum Water Well Construction and Sealing Standards for the Protection of Ground Water Quality, Alameda County. Preliminary Edition, 1962
- 2. Bulletin 74-3: Water Well Standards Del Norte County, 1966
- 3. Bulletin 74-4: Water Well Standards. Central, Hollywood, Santa Monica Basins, Los Angeles County, 1974
- 4. Bulletin 74-5: Water Well Standards: San Joaquin County. Final Supplement, 1969
- 5. Bulletin 74-5: Water Well Standards: San Joaquin County. Appendix E: Formation Testing. Preliminary Editon, 1965
- 6. Bulletin 74-6: Water Well Standards: Fresno County, 1968
- 7. Bulletin 74-7: Water Well Standards Arroyo Grande Basin San Luis Obispo County, 1971
- 8. Bulletin 74-8: Water Well Standards Shasta County, 1968
- 9. Bulletin 74-9: Water Well Standards Ventura County, 1968
- 1. California Laws for Wells, October 2016
- 2. Statewide Advisory: Sealing Materials for Water Wells, Monitoring Wells, Cathodic Protection Wells, and Geothermal Heat Exchange Wells, September 2015
- 3. Bulletin 74-90: California Well Standards, June 1991
- 4. Bulletin 74-81: Water Well Standards - State of California, December 1981
- 5. Geothermal Heat Exchange Wells
- 6. Water Facts 5. California Well Standards Questions and Answers, June 1992
Submit a Well Completion Report
California Water Code Section 13751 requires that anyone who constructs, alters, or destroys a water well, cathodic protection well, groundwater monitoring well, or geothermal heat exchange well must file with the Department of Water Resources a report of completion within 60 days of the completion of the work. Drillers submit their well completion reports with the Online System of Well Completion Reports (OSWCR, say "Oscar"). OSWCR users create an account based on their C-57 license that DWR will validate. Upon approval users will be able to submit Well Completion Reports.
Public Access to Well Completion Reports
California Water Code Section 13752 allows for the release of copies of well completion reports to governmental agencies and to the public. DWR has redacted the personal information from the approximately 800,000 reports on file. They are available online at no charge via a web mapping application here:
If you are unable to find reports of interest using this application, Department staff can process your request, but a fee may be charged as provided by the law. If you are interested in requesting well completion reports instead of using the free online access, please fill out and submit a Well Completion Report Request Form.
In California, regulatory authority over well construction, alteration, and destruction activities rests with local jurisdictions (cities, counties, or water agencies), who have the authority to adopt a local well ordinance that meets or exceeds DWR Well Standards. Permitting and enforcement are carried out by the local enforcing agency (LEA), such as the County Department of Environmental Health. LEAs are listed below alphabetically by county; cities and water agencies are listed under the counties they reside in. Please help us keep this list up to date.
(Eastern Alameda County including Dublin, Pleasanton, Livermore and Sunol
Alameda County Flood Control and Water Conservation District)
City of Santa Cruz
Construction of a water well begins with making a hole, using 1 of the 3 methods shown in Figure 1. As the hole is excavated, the licensed well driller logs the depths at which water is produced. This information is used to design the well. Read about each method and view the most common drilling methods at WellOwner.org.
Figure 2 is an example of typical water well construction.The well "casing" is a metal or plastic pipe that is centered in the hole. The "well screen" is the perforated section of casing next to the aquifer. The remainder of the casing is "blank" with no perforations. Once the casing is inserted, a "filter pack" of sand and/or gravel is placed around the well screen to filter fine soils from water entering the well. The rest of the space between the hole and the blank casing (annular space), is sealed with highly waterproof materials to prevent contaminants from flowing through the space. Finally, the well is completed when the pump is placed and the wellhead features are constructed, including a concrete pad which slopes away from the well.
Protect Your Water Well
Proper design and construction are key to a well's success. The well should be carefully located away from septic systems and other pollutant sources to minimize potential for contamination. The annular space should be sealed with materials that meet statewide minimum well standards and local well ordinance requirements.
Simple preventative measures can ensure your well water stays clean:
- Establish zones of protection around your well, limiting low, medium, and high impact activities as shown in A Guide for Private Domestic Well Owners.
- Perform routine maintenance and testing: Inspect the well for cracks or other possible sources of contamination and test water quality on a regular schedule as described in A Guide for Private Domestic Well Owners.
Properly Seal Abandoned Wells
Abandoned wells can be pathways for pollutants to enter the groundwater. They also pose a threat to public health and safety – children, animals, or even adults can fall into abandoned wells, causing injury or death. Well Decommissioning...There's a Plan for That (video, 3:18 minutes) by the Natural Resources Conservation Service of California provides important information for all landowners to recognize and address abandoned wells with footage from an actual well destruction in Sacramento County in this brief video, Well Decommissioning...There's a Plan for That . If you know or suspect of an abandoned well, contact your local enforcing agency.
- 1. A Guide for Private Domestic Well Owners, State Water Resources Control Board, March 2015
- 2. Guía para los Dueños de Pozos Domésticos , Junta Estatal de Control de los Recursos de Agua de California, Marzo de 2015
- 3. Abandoned Wells, Natural Resources Conservation Service, Davis, CA, January 2010
- 4. Water Well Design and Construction, University of California, Davis with Natural Resources Conservation Service, 2003
- 5. Drinking Water From Household Wells , U.S. Environmental Protection Agency, January 2002
- 6. Water Facts 5. California Well Standards Questions and Answers DWR, June 1992
- 7. Water Wells... and What You Should Know About Them , DWR, October 1977
Local & Regional Resources
- 1. Well Permitting Agencies are the local agencies responsible for issuing well construction, modification, and destruction permits.
- 2. Groundwater Sustainability Agencies are the local/regional agencies being formed under the 2014 Sustainable Groundwater Management Act to manage groundwater.
- 3. Regional Water Quality Control Boards are responsible for developing basin plans for their hydrologic areas, issuing waste discharge permits, taking enforcement action against violators, and monitoring water quality.
- 1. Contractors State License Board licenses water well drilling contractors under the C-57 license designation.
- 2. State Water Resources Control Board has broad regulatory authority to protect water quality.
- 3. Department of Toxic Substance Control provides information on hazardous waste disposal and reporting spills or illegal dumping.
- 4. California Groundwater Association is a non-profit organization representing all segments of the groundwater industry in California.
- 5. Groundwater Resources Association of California is a professional association dedicated to resource management that protects and improves groundwater supply and quality through education and technical leadership.
- U.S. EPA - Private Drinking Water Wells provides information to help homeowners care for their private wells and protect their health.
- Natural Resources Conservation Service provides leadership in a partnership effort to help people conserve, maintain, and improve our natural resources and environment. Financial and technical assistance for well decommissioning may be available.
- National Groundwater Association is a national non-profit organization for the groundwater industry.
- The Groundwater Foundation is a national nonprofit charitable organization dedicated to educate people and inspire action to ensure sustainable, clean groundwater for future generations.
North Central Region
Water Resources Engineer
Groundwater Supply Assessment & Special Studies Section
3500 Industrial Blvd
West Sacramento, CA 95691
Well Completion Reports/OSWCR
901 P Street
P.O. Box 942836
Sacramento, CA 94236
Senior Engineering Geologist
901 P Street
P.O. Box 942836
Sacramento, CA 94236