Oil and gas companies have injected more than 121 million litres of fluids containing diesel fuel underground without first getting Government approval, a report by congressional Democrats in the United States said.
Politicians said large companies, such as Halliburton and BJ Services Co, appeared to violate the Safe Drinking
Water Act because the companies never obtained permission from state or federal authorities to use diesel fuel.
The probe found no evidence that the use of diesel contaminated water supplies in the 19 states where it was injected in a procedure called hydraulic fracturing. But senior Democrat Harry Waxman said: "Our investigation showed this practice has been continuing in secret and in apparent violation" of the Safe Drinking Water Act.
None of the companies surveyed could provide data about whether they performed hydraulic fracturing in or near underground sources of drinking water, the panel said.
