Hydraulic fracturing uses a host of highly toxic chemicals — the impacts of which are for the most part unknown — that could be contaminating drinking water supplies, wildlife and crops, according to a report released Thursday by a California science panel.
The long-awaited final assessment from the California Council on Science and Technology said that because of data gaps and inadequate state testing, overwhelmed regulatory agencies do not have a complete picture of what oil companies are doing.
The risks and hazards associated with about two-thirds of the additives used in fracking are not clear, and the toxicity of more than half, the report concluded, remains "uninvestigated, unmeasured and unknown. Basic information about how these chemicals would move through the environment does not exist."
Jane Long, the report's co-lead, said officials should fully understand the toxicity and environmental profiles of all chemicals before allowing them to be used in California's oil operations.
Recycled oil field wastewater used for crop irrigation may contain chemicals used during fracking and other well stimulation procedures, the report said. While treatment of that water is required, the testing is not adequate, the report said. Long said researchers did not find strong evidence of fracking fluids in irrigation water but added: "What we did find was that there was not any control in place to prevent it from happening."
The probability of toxic exposure to humans and the environment is low, but no studies have been conducted assessing the risk, the report's authors said.
Sen. Fran Pavley (D-Agoura Hills) said that she planned Monday to propose amendments to legislation she already had introduced, based on some of the report's findings. They include the development of an approved list of chemicals, with known toxicity, for use in oil development as well as the phasing out of the use of unlined pits to dispose of oil field waste.
"Government agencies, the public in general and residents living near well sites need to know in detail about the presence of dangerous chemicals mixed in water used in fracking and then pumped to the surface as byproducts," Pavely said in a statement.
The potential for contamination linked to fracking, according to the report, demands that the state conduct more thorough studies in order to close significant data gaps.
For example, there is little evidence to show that oil activities are contaminating groundwater, Long said, but little analysis has been done.
"We think the fact that we haven't looked for it is an issue," Long said. "You can't find what you don't look for."
Seth Shonkoff, lead author on the public health sections of the report, said he was surprised to learn during his research that recycled wastewater from oil fields was being used on crops.
"We've got to know what to test for … to know that what we are putting onto the crops is safe," he said. "Until we have that data, I don't know how we can assure farmers and consumers that their food is safe."
Among the findings of the report, commissioned by the California Natural Resources Agency and written by the California Council on Science and Technology and Lawrence Berkeley National Laboratory:
-- Injection wells that the state is allowing to dispose of oil field wastewater into federally protected aquifers may have received water containing fracking fluids.
-- Oil operations in federal waters offshore are discharging wastewater directly into the ocean, against EPA regulations.
-- More than half the produced water from fracked wells is disposed of in unlined pits. "We do not know how long hydraulic fracture chemicals persist in produced water or at what concentrations or how these change in time, which means that hazardous levels of contaminants … cannot be ruled out."
-- About one-third of the oil field wastewater pits in the Central Valley are operating without proper permits.
-- About 1.7 million people in Los Angeles live or work within one mile of an active oil or gas well, and atmospheric concentrations of pollutants near those sites "can present risks to human health." The report recommended an extensive epidemiological study of residents living near oil production sites. California does not regulate how close oil operations can be from residences, schools or hospitals. The report recommends that California adopt a setback requirement.
-- Oil and gas development causes habitat loss and fragmentation in ecologically sensitive areas of Kern and Ventura counties.