Long-Term Viability of Underground Natural Gas Storage in California: An Independent Review of Scientific and Technical Information

Release Date: January 18, 2018 | Last Updated Date: February 5, 2018

In response to Governor Brown’s January 2016 state of emergency proclamation regarding the Aliso Canyon gas leak, SB 826 (Leno, 2016) requested that the California Council on Science and Technology (CCST) provide the State with up-to-date information on all currently operating underground natural gas storage fields in California. CCST was instructed to provide an independent technical assessment answering three key questions about:

  • The risks California’s underground gas storage facilities pose to health, safety, environment, and infrastructure;
  • Whether California needs underground gas storage to provide for energy reliability through 2020; and
  • How implementation of California’s climate policies changes the future need for underground gas storage.

From a statewide field of leading energy researchers, CCST selected Jens T. Birkholzer, PhD, and Jane C.S. Long, PhD, to serve as co-chairs of the 12-member CCST Report Steering Committee – which supervised 21 Report Authors with expertise spanning hydrogeology and reservoir engineering, risk assessment, public and occupational health, greenhouse gas (GHG) emissions, and energy analysis and economics. Each report chapter was subject to a peer review process by independent experts, while another independent expert served as Report Monitor to oversee the process, ensuring that peer review comments were sufficiently addressed in the final report. An additional Oversight Committee reviewed the entire process, including conflict-of-interest declarations.

The report’s findings and conclusions are based on a review of published literature and official and voluntary databases, which the Report Authors compiled between January through September 2017, and delivered to the California Public Utilities Commission in January 2018. Key findings and conclusions include:

  • Safety: The risks associated with underground storage (UGS) facilities can be managed, and, with appropriate regulation and safety management, may become comparable to risks in other types of energy facilities found acceptable in California, such as oil refineries and natural gas power plants. At each UGS facility, the State should ensure timely and thorough implementation of the new regulations coming into force in 2018 set by the California Department of Conservation’s Division of Oil, Gas, and Geothermal Resources (DOGGR). Those regulations emphasize new and safer well completions, risk and safety management plans, and requirements for well integrity testing and monitoring. The report recommends that the State go further and require more quantitative risk assessment activities, including consideration of human and organizational factors affecting risk. The State should also implement an independent and mandatory review program to evaluate the effectiveness of these new regulations and the rigor of their application in practice, with opportunity for public comment and public dissemination of the review results.
  • Facility-by-Facility Evaluation: Any industrial operation involves some risk to health, safety, and environment. This report assessed various risk-related characteristics across UGS facilities in California, and found a small list of facilities had relatively higher potential risk compared to others.
  • Reliability of Natural Gas Supply: California’s energy system currently requires natural gas and UGS facilities to run reliably, primarily because many residential and commercial buildings in California rely on natural gas for heating during the winter, and because natural gas provides electricity when solar and wind power are not available. The peak demand for natural gas during the winter currently exceeds the ability of pipelines to bring natural gas into the State of California, so natural gas must be stored during periods of low demand in order to have it available to meet peak demand.
  • Near-Term Alternatives to UGS: Closing any or all UGS facilities in the near term would involve replacing UGS facilities with new pipelines or natural gas storage capacity, and require very large investments. Such new natural-gas-related infrastructure would bring its own risks and would further obligate the State to the use of natural gas for decades. The risks, costs, and benefits associated with alternatives to UGS storage should be evaluated accordingly.
  • Long-Term Need for Underground Gas Storage: California’s climate policies in future decades could still necessitate the continued use of natural gas. Also, energy systems that meet the climate goals may require underground storage of natural gas, biogas, or hydrogen, as well as sequestration of carbon dioxide. The State should develop a more complete and integrated plan to understand how the role of natural gas might evolve; assess possible energy portfolios that both meet GHG emission constraints and achieve energy reliability; and consider the potential need for UGS facilities in the future.

Additional Downloads

Executive Summary

Download

Summary Report

Download

CCST One-Pager

Download

Public briefing PPT presentation

Download

Front Matter

Download

Chapter 1 Abstract

Download

Chapter 1 Section 1.0: Introduction

Download

Chapter 1 Section 1.1: Characteristics of California’s underground natural gas storage facilities

Download

Chapter 1 Section 1.2: Failure modes, likelihood, and consequences

Download

Chapter 1 Section 1.3: Effects of age and integrity on underground gas storage capacity

Download

Chapter 1 Section 1.4: Human health hazards, risks, and impacts associated with underground gas storage in California

Download

Chapter 1 Section 1.5: Quantification of greenhouse gas emissions from underground gas storage in California

Download

Chapter 1 Section 1.6: Risk mitigation and management

Download

Chapter 1 Section 1.7: Summary and Conclusions

Download

Chapter 1 Section 1.8: References

Download

Chapter 1 Appendix 1.A: California gas storage and geologic trap type

Download

Chapter 1 Appendix 1.B: Dispersion modeling

Download

Chapter 1 Appendix 1.C: Air Pollutant Emission Inventory Assessment

Download

Chapter 1 Appendix 1.D: Human Population Proximity analysis

Download

Chapter 1 Appendix 1.E: Efforts to Seek Information on Stored Gas Composition

Download

Chapter 1 Appendix 1.F: Operator Response Letters

Download

Chapter 1 Appendix 1.G: Best Practices in Occupational Safety and Health

Download

Chapter 2: Does California Need Underground Gas Storage to Provide for Energy Reliability through 2020?

Download

Chapter 3: How will implementation of California’s climate policies change the need for underground gas storage in the future?

Download

Appendices

Download

Related Publications

Biomethane in California Common Carrier Pipelines: Assessing Heating Value and Maximum Siloxane Specifications
Page from biomethane report
A study analyzing regional and gas-corporation-specific issues relating to the minimum heating value and maximum siloxane specifications.
California Public Interest Energy Research (PIER) Independent PIER Review Panel Interim Report
PIER 2004 Interim Report Cover
This report is the interim report responding to Senate Bill 1038, requiring that the California Energy Commission (CEC) convene an independent review and critique of the Public Energy Interest Research (PIER) Program.
The Legacy of Project California: Closeout Report
The Legacy of Project California: Closeout Report
Launched in the summer of 1992, Project California was a visionary effort that brought together leaders in industry, government, labor, and academia to mobilize the unique resources of this state in addressing the challenges of economic restructuring.