Two years ago, the state of California (USA) ordered oil companies to test fracking wastewater for harmful chemicals. The results are in. A key finding from this research is that fracking wastewater contains high levels of benzene. "Data culled from the first year of those tests found significant concentrations of the human carcinogen benzene in this so-called 'flowback fluid.' In some cases, the fracking waste liquid, which is frequently reinjected into groundwater, contained benzene levels thousands of times greater than state and federal agencies consider safe," the Los Angeles Times reported.