The California Council on Science and Technology, which authored the report on which the Bureau of Land Management based its decision to resume auctions of oil and gas leases on federal lands in California, has released the report online.
“Responsible decision making requires good science to balance economic potential with environmental concerns,” CCST Executive Director, Dr. Susan Hackwood said in a statement. “This report provides the most objective, up-to-date, peer-reviewed assessment available to inform thoughtful policy making in California, while also characterizing issues that require further study.”
The CCST released both the full 400-page report and a 32-page Executive Summary. Both can be downloaded via the links provided here, or from the CCST website.
The report, which took nearly a year to prepare, arrived at several key conclusions:
Well stimulation in California is different than in other states such as Texas and North Dakota due to differences in the geology of the petroleum reservoirs.
Future well stimulation in California will likely be quite similar to today’s practices, using relatively shallow rather than deep stimulation.
Sharply lower estimates of Monterey Shale reserves make large-scale production there, using deep wells, highly uncertain.
Fracking in California accounts for only a small fraction of statewide water use. Hydraulic fracturing operations in California consume 130,000 to 210,000 gallons of water per well, compared to about 4 million gallons in the Eagle Ford Formation in Texas.
There are no publicly reported instances of potable water contamination from subsurface releases in California. However, because more than half of the stimulated oil wells in California have shallow depth (less than 2,000 feet), shallow fracking does pose a potential risk for groundwater.
The toxicity of chemicals used in fracking fluids warrants further review. Most chemicals used in California well stimulations are not highly toxic, but a few biocides and corrosion inhibitors are acutely toxic, and information is lacking for about a third of the chemicals used.
Chemicals used for fracking may mix with produced water. Some produced water is diluted with fresh water and used in agriculture, and some is stored in unlined pits where it could seep into the groundwater.
Well stimulation technologies as practiced in California do not create a seismic hazard. The pressure increases from hydraulic fracturing are too small and too short in duration to produce a felt, let alone damaging, earthquake.
Overall, in California, the direct environmental impacts of well stimulation practice appear to be relatively limited. If stimulation activities increase, the main effects will be related to production activities, such as trucking traffic, rather than fracking.