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Chemicals of Concern - Groundwater Information Sheets | Laws and Regulations | Groundwater Links

Chemicals of Concern (COC) - Groundwater Information Sheets

The Groundwater Special Studies Unit has compiled technical information on some higher profile Chemicals of Concern (COCs) that may pose a threat to groundwater quality in the State. Groundwater Information Sheets for each COC have been prepared and are periodically updated to reflect current knowledge and technology.

Groundwater Information Sheets include the following information

  • Chemical formula, aliases, and identification numbers
  • Regulatory and water quality levels
  • Summary information pertaining to detection in California’s groundwater
  • Analytical test methods, regulatory testing requirements, and known analytical limitations
  • Discussion of anthropogenic and natural sources
  • Environmental fate and transport characteristics
  • History of occurrence
  • Remediation/treatment technologies
  • Adverse health effects
  • Key references

COCs Groundwater Information Sheets

U.S. EPA List of Priority Drinking Water Contaminants for Regulatory Consideration

Related Laws and Regulations

AB 599 (Liu) - Groundwater Quality Monitoring Act of 2001

The Groundwater Quality Monitoring Act of 2001 - Assembly Bill 599 (AB 599 Liu) - was established to improve comprehensive groundwater monitoring and increase the availability of information about groundwater quality to the public. AB 599 specified that the comprehensive monitoring program integrate projects established in response to the Supplemental Report of the 1999 Budget Act (GAMA Program), strive to take advantage of and incorporate existing data whenever possible, and prioritize groundwater basins that supply drinking water.

AB 599 required that the SWRCB, in coordination with an Interagency Task Force and Public Advisory Committee integrate existing monitoring programs and design new program elements, as necessary, to establish a comprehensive statewide groundwater quality monitoring program.

This effort resulted in a Report to the Governor and Legislature (released November 2003) that describes the comprehensive groundwater quality monitoring program for the state. As part of the AB 599 effort, in collaboration with the SWRCB, the U.S. Geological Survey (USGS) prepared a plan to monitor California's groundwater quality. The report outlining the plan is entitled: “Framework for a Ground-Water Quality Monitoring and Assessment Program for California” as is included in Appendix E of the SWRCB’s Report to the Governor and Legislature.

AB 599 has affected all the GAMA Program’s Projects, including the Priority Basin Project.

Proposition 50 - Water Security, Clean Drinking Water, Coastal and Beach Protection Act

The Water Security, Clean Drinking Water, Coastal and Beach Protection Act of 2002 was a ballot initiative measure approved by voters in a statewide general election as Proposition 50. Proposition 50 provided funds for competitive grants for projects to protect communities from drought, protect and improve water quality, and improve local water security by reducing dependence on imported water. Under Proposition 50, these projects could include groundwater recharge and management projects.

Funding for the GAMA program is identified in Proposition 50, Chapter 8. Integrated Regional Water Management which added Section 79562 to the Water Code.

AB 1747 (Oropeza & others) – Bond Law for Proposition 50 Projects

AB 1747 includes requirements and regulations concerning the implementation of Proposition 50. Section 1(g) of the bill requires that groundwater projects, and projects that affect groundwater, shall include monitoring requirements consistent with the Groundwater Quality Monitoring Act of 2001 (AB 599).

AB 2222 (Caballero) – Groundwater Information Accessibility and Identification of Communities Reliant on Contaminated Groundwater

The Groundwater Quality Monitoring Act of 2001 (AB 599) requires the State Water Resources Control Board to integrate existing monitoring programs and design new program elements, as necessary, to establish a comprehensive monitoring program capable of assessing each groundwater basin in the state through direct and other statistically reliable sampling approaches.

AB 2222 (Caballero, Chapter 670, Statutes of 2008) required the State Board to identify, and recommend to the Legislature, funding options to extend the comprehensive monitoring program until January 1, 2024. The bill also required the State Board to make recommendations to enhance public accessibility of information on groundwater conditions. A report titled “Public accessibility to Information About Groundwater Conditions” was submitted to the legislature in 2010.

AB 2222 also requires that the State Board, on or before January 1, 2012 submit to the legislature a prescribed report that identifies:

  1. Communities that rely on contaminated groundwater as a primary source of drinking water.
  2. Groundwater sources for the communities identified in (1), identify the principal contaminants in that groundwater, and identify contamination levels.
  3. Identifies potential solutions and funding sources to clean up or treat groundwater or to provide alternative water supplies to ensure the provision of safe drinking water to communities identified in (1).

SBX2 1 (Perata) – Nitrate Pilot Projects in Tulare Lake and Salinas Basins

Under the Porter-Cologne Water Quality Control Act, the State and Regional Water Boards are the principal state agencies with authority over matters relating to water quality. SBX2-1 required the State Board to develop pilot projects in the Tulare Lake Basin and Salinas Valley focused on nitrate contamination. The bill authorized the creation of an interagency task force to oversee the pilot projects.

The State Board will submit a report to the Legislature on the scope and findings of the projects, and is required to implement recommendations for developing a groundwater cleanup programs in the areas identified above.

More information can be found on the Nitrate Project Website.

SB 1938 – Monitoring Components for Groundwater Management Plans

Existing law authorizes a local agency to prepare and implement a groundwater management plan. The Local Groundwater Assistance Fund provides money that may be used by the Department of Water Resources to assist local public agencies by awarding grants to those agencies to conduct groundwater studies or to carry out groundwater monitoring and management activities.

SB 1938 (Machado, Chapter 603, Statutes of 2002) required all groundwater management plans to include and implement certain monitoring components in order to be eligible to receive state funding for groundwater management projects.

SB 4: Oil and Gas: Well Stimulation

On September 20th 2013, the Governor signed Senate Bill 4 (SB 4) to establish a comprehensive regulatory program for oil and gas well stimulation treatments (e.g., hydraulic fracturing, acid well stimulation), which includes, a study into the environmental, occupational and public health hazards and risks, the development of regulations, a permitting process, and public notification and disclosure. SB 4 requires the Division of Oil, Gas, Geothermal Resources (DOGGR), in consultation with other state agencies, including the Water Boards, to create the regulatory program for areas where well stimulation treatments occur.

SB 4 also launches the development of a groundwater monitoring program for oil and gas production areas in California. The groundwater monitoring model criteria associated with the program must be developed by July 1, 2015. The model criteria will include, among other things, spatial sampling scales, methods of sampling, and methods for conducting a monitoring program.

Related Groundwater Links

Water Education Foundation

Division of Drinking Water (formerly California Department of Public Health)

Department of Water Resources (DWR)

Lawrence Livermore National Laboratory

United States Geological Survey (USGS)

United States Environmental Protection Agency (U.S.EPA)

State Water Resources Control Board

Department of Toxic Substances Control

Department of Pesticide Regulation

Miscellaneous Links

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State Water Resources Control Board
Division of Water Quality
Groundwater Ambient Monitoring & Assessment Program (GAMA)
1001 I Street, 15th Floor
Sacramento, CA 95814

Telephone: (916) 341-5577
Fax: (916) 341-5463