The peer-reviewed study from the California Council on Science and Technology was required as part of fracking legislation the state passed in 2013.
Jane Long was a lead author on the report. She says there’s no evidence of direct negative impacts on health or groundwater. But she says agencies haven’t been looking for such impacts. And she says there’s a lot still unknown about the chemicals involved.
"We should know what they are. We should know what their environmental characteristics are," Long said. "We only know the toxicity for example for about two-thirds of the chemicals that are used. A third of them we have no toxicity information."
The report finds fracking waste water is often not tested for chemicals and could potentially lead to contamination.
Democratic Senator Fran Pavley wrote the 2013 fracking legislation. She says she will incorporate some the report’s suggestions into a new bill she’s written that deals with oil and gas regulations.
In a statement, Pavley stressed the need for transparency around fracking.
"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," she said.
The Sierra Club lauded the report as confirmation of its view that fracking is dangerous.
"Today's California Natural Resources Agency report confirms what we already know: dirty oil and gas fracking poisons our air and water," said Sierra Club Executive Director Michael Brune.
But the oil industry took a different view. Sabrina Lockhart is with Californians for Energy Independence, an advocacy group.
"This sound science, coupled with the most comprehensive oil regulations in the nation, ensures California remains on a path of responsible production to secure our state's energy needs,” she said.