California Council on Science and Technology and Berkeley Lab Release Scientific Assessment of Hydraulic Fracturing in California
July 9, 2015
SACRAMENTO - In collaboration with the Lawrence Berkeley National Laboratory (Berkeley Lab), the
California Council on Science and Technology (CCST) today released a peer-reviewed independent
scientific assessment that discusses how hydraulic fracturing and acid well stimulation could affect
water, atmosphere, seismic activity, wildlife and vegetation, and human health in California. The
report also identifies knowledge gaps and alternative practices that could avoid or mitigate these
The report was prepared for the California Natural Resources Agency in response to Senate Bill 4.
Issued today are the second and third volumes in a three-volume CCST study of hydraulic fracturing
and acid well stimulation in California. Volume I was released in January 2015.
"We applaud state leaders for seeking an independent scientific assessment to inform policy
choices about hydraulic fracturing and acid stimulation. CCST was created as an independent
organization via the Legislature to do exactly this kind of careful scientific evaluation," said
CCST Executive Director Dr. Susan Hackwood.
A science team composed of Berkeley Lab researchers and subcontractors developed the findings
based on publically available data, original analyses, and a review of relevant literature.
CCST appointed members of a steering committee based on technical expertise and a balance of
viewpoints. "CCST assembled a steering committee for this report from some of the finest experts on
oil and gas production, environment, water, risk assessment and geology," said CCST's Dr. Jane C. S.
Long, the Steering Committee Chairman and science lead of the assessment.
Dr. Jens Birkholzer, the Principal Investigator of the assessment and Division Deputy of Berkeley
Lab's Earth Sciences Division, added, "A highly qualified group of scientists with many years of
research experience worked intensely for over a year to collect, analyze and interpret a wide
variety of available information on hydraulic fracturing and acid stimulation in the state. " Dr.
Long adds, "This study would not have been possible in this short timeframe without the expertise
and Herculean effort of the Berkeley Lab team."
The steering committee in collaboration with the science team developed conclusions and
recommendations under seven major principles designed to improve the safety of hydraulic fracturing
and acid stimulation in California:
Maintain, expand and analyze data on the practice of hydraulic fracturing and acid stimulation
Based on a review of published literature and official and voluntary databases,
one-fifth of oil and gas production in California over the last decade came from wells that had been
subject to hydraulic fracturing. Compared to practices in other states, current hydraulic fracturing
in California tends to be performed in shallower vertical wells as opposed to horizontal and
requires much less water per well. Operators in California use about 800 acre-feet (about a million
m3) of water per year for hydraulic fracturing. This does not represent a large amount of freshwater
other human water use. Depending on the local scarcity of water, recycling the water
used to create hydraulic fractures may have modest benefits. Far more water is used for enhanced oil
recovery using water or steam flooding in the same fields, and large volumes of water of various
salinities and qualities get produced along with the oil. Produced water from oil and gas
production, appropriately tested and treated, has potential for beneficial reuse. The report
recommends identifying opportunities for water conservation and reuse in the oil and gas industry as
The report also points out the need for improving and modernizing public record
keeping for oil and gas development.
Prepare for potential future changes in hydraulic fracturing and acid stimulation practice in
Near-term expanded production in the Monterey Formation seems unlikely, but the
state should request a reliable, scientific assessment of this potential. The report identifies the
footprint of potential production in the Monterey Formation and none of this geography is more than
20 km from existing oil and gas production. The state should monitor drilling into this formation
as an indication of potential new production. Use of hydraulic fracturing will most likely continue
in and near
existing oil fields in the San Joaquin Basin and to a lesser extent in other areas of
Account for and manage both direct and indirect impacts. Direct
impacts of hydraulic fracturing are caused by the activity of hydraulic fracturing itself. All the
major potential direct
impacts identified in this study (such as potential contamination of
groundwater) are due to the use of hazardous chemicals. The report recommends full disclosure of
chemicals used, disallowing the use of any chemical that has unknown environmental properties, and
limiting the use of hazardous chemicals to avoid some of the potential impacts.
fracturing enables oil and gas development where it would otherwise not occur. The impacts of this
development are indirect impacts of hydraulic fracturing. The report recommends evaluation of
indirect impacts of concern (such as disposal of produced water, habitat disruption, emissions,
health impacts, oil spills etc.) for all oil and gas development, rather than just the portion of
development enabled by well stimulation.
Manage water produced from hydraulically
fractured or acid stimulated wells appropriately.
The report finds that operators dispose of
over half of the produced water from hydraulically fractured in pits which allow water to percolate
into the ground and thus could contaminate groundwater. The report recommends phasing out disposal
in percolation pits unless appropriate testing, treatment and regulatory oversight are implemented.
The report also concludes that, to date, there have been no recorded cases of induced seismicity
linked to disposal of produced water by underground injection in California, but given the risks
seen in other regions and California's propensity for earthquakes, more research and monitoring is
Add protections to avoid groundwater contamination:
This assessment did not find recorded
negative impacts from hydraulic fracturing chemical use in California, but no agency has
systematically investigated possible impacts. The report does identify a few locations in the San
Joaquin Valley and Los Angeles Basin where shallow hydraulic fracturing occurs near protected
groundwater. This presents the possibility that groundwater may be at risk and recommends that
these situations get closer attention, monitoring and oversight.
One important possible pathway for hydraulic fracturing chemicals to leak is through hydraulic
fractures intersecting other nearby wells. The report recommends a review of the effectiveness of
regulations designed to prevent these potential subsurface contamination pathways.
Understand and control emissions and their impact on environmental and human health:
California, oil produced from hydraulically fractured reservoirs emits fewer greenhouse gases per
barrel than oil produced in other ways, such as steam injection.
The report also notes that toxic air pollutant concentrations may be more elevated near active
oil and gas development than regional averages. The report recommends measuring toxic air
contaminant concentrations and monitoring health risks and impacts near all oil and gas wells to
assess the need for further controls. Such controls may include emissions controls and limits on the
proximity of oil and gas development to human populations to protect human health.
Take an informed path forward:
The report identifies a set of important data gaps and
detailed research priorities to address many remaining unanswered questions about the impacts of
well stimulation-enabled oil and gas production in California, and recommends establishing a
standing scientific advisory committee to inform decisions on the regulation of oil and gas
The full three-volume report, a summary report and an executive summary can be viewed at: http://ccst.us/publications/WST
Volume I, which was released in January 2015, describes how well stimulation technologies
work, how and where operators deploy these technologies for oil and gas production in California,
and where they might enable production in the future.
Volume II, issued today, discusses how hydraulic fracturing and acid stimulation could
affect water, atmosphere, seismic activity, wildlife and vegetation, and human health in California.
Volume III, also released today, presents four case studies that assess environmental
issues and qualitative risks for specific geographic regions: Offshore, the Los Angeles Basin, the
Monterey Formation, and the San Joaquin Basin.
The Summary Report summarizes the issues in all three volumes and provides all the
conclusions and recommendations for the series.
The California Council on Science and Technology is a nonpartisan, not-for-profit corporation
established in 1988 via a unanimous vote of the California Legislature. Bringing together
world-class expertise from academia, the national labs, companies and a broad array of Senior
Fellows who are distinguished scientists and technical experts, CCST offers expert advice to the
Governor, the Executive Branch and the Legislature on science and technology-related policy issues.
In recent years, CCST has produced a series of reports on California's technical innovation, water,
energy, STEM and digitally enabled education.
Lawrence Berkeley National Laboratory addresses the world's most urgent scientific challenges by
advancing sustainable energy, protecting human health, creating new materials, and revealing the
origin and fate of the universe. Founded in 1931, Berkeley Lab's scientific expertise has been
recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S.
Department of Energy's Office of Science. For more, visit www.lbl.gov. The Office of Science is the
single largest supporter of basic research in the physical sciences in the United States, and is
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