This page provides information and resources for the public regarding Well Stimulation Treatment (WST) in California.
Explore the sections below or use the links to the right for information about specific topics.
Effective July 1, 2015, there are new permitting requirements for well stimulation treatment (WST). Prior to performing WST, the operator must submit a permit application for DOGGR’s review and possible approval. WST cannot be performed on any well without a valid WST permit issued by DOGGR.
Well stimulation treatment permits will be posted within 5 business days of issuing the permit.
See the links on the right for WST permits issued by DOGGR.
Effective July 1, 2015, new disclosure reporting requirements are in place. Within 60 days following the cessation of a well stimulation treatment, operators must provide specified information regarding the composition and disposition of well stimulation fluids, including, but not limited to, hydraulic fracturing fluids, acid well stimulation fluids, and recovered fluids. This information is posted to a searchable WST Disclosure Index that is accessible to the public.
See the links on the right for public disclosure information provided by operators.
SB 4 required the preparation of an Environmental Impact Report (EIR) to analyze the statewide impacts of well stimulation treatments. Suggestions of the content and scope of the EIR were taken at several public scoping meetings around the state and the draft EIR was made available for public review and comment.
The Notice of Preparation for this EIR (required by CEQA) can be found here:
Notice of Preparation for SB4 Environmental Impact Report
Effective July 1, 2015, the Division of Oil, Gas, and Geothermal Resources certified the Final EIR mandated by SB 4.
Environmental Impact Report
Pursuant to Senate Bill 4, the California Natural Resources Agency (CNRA) commissioned the California Council on Science and Technology (CCST) and Lawrence Berkeley National Laboratory (LBNL) to conduct an independent scientific assessment of well stimulation, including hydraulic fracturing, in California. On January 14, 2015, CCST released Volume I of the assessment to the public.
Volume I, which is titled "An Independent Scientific Assessment of Well Stimulation Technologies in California: Well Stimulation Technologies and their Past, Present, and Potential Future Use in California", provides the factual basis describing what well stimulation treatments (WST) are, how they are conducted in general and practiced in California, and where they have been and are being used for oil and gas production in the state.
The full independent scientific assessment is issued in three volumes. As of July 9th, volumes II and III have been released. Volume II discusses how well stimulation could affect water, atmosphere, seismic activity, wildlife and vegetation, and human health. Volume II also reviews available data, and identifies knowledge gaps and alternative practices that could avoid or mitigate these possible impacts. Volume III presents case studies to assess environmental issues and qualitative hazards for specific geographic regions, based on findings in Volume I and Volume II.
Links to these volumes:
Volume I (Full PDF)
Volume II (Full PDF)
Volume III (Full PDF)
More links and information are available on the
California Council on Science and Technology (CCST) Project Description page regarding the study and the report volumes.
Wells require maintenance and cleanout operations. Information on these operations can be found here:
- Well Maintenance and Cleanout Index (Available soon!)
Chemical Index – The Common Chemistry searchable chemical index is provided by Chemical Abstracts Service (CAS) as a public service:
- Common Chemistry chemical index
SB 4 required DOGGR to prepare for the California Legislature a comprehensive report, submitted annually, on well stimulation treatments in the state.
The objective of the Well Stimulation Treatment First Annual Report is to provide aggregated information to the Legislature and public regarding WST in California. The report covers well stimulation and related activities performed in California from January 1, 2014 through September 30, 2015. These dates cover the implementation period of SB 4, authored and chaptered in 2013, through the first three months following the end of the interim period. Information about actual and specific WSTs performed during this period is derived from operator disclosures (post-WST job reports) received during these periods. (WST Disclosure Website)
The report can be found here:
- Well Stimulation Treatment First Annual Report - 2015
annual report satisfies the legislative report requirements of Senate Bill 4 (Pavley, Chapter 313, Statutes of 2013) regarding well stimulation treatment. Part 1 of the report summarizes the objective and scope of this report. Part 2 provides a response to each legislative reporting requirement. The appendices provide references and sources of the data, as well as a glossary of terms used. During the reporting period, 579 well stimulation treatments were performed, all but one in western Kern County in relatively mature oil fields.