The government has failed to inspect thousands of oil and gas wells it considers potentially high risks for water contamination and other environmental damage, congressional investigators say.
The report, obtained by The Associated Press before its public release, highlights substantial gaps in oversight by the agency that manages oil and gas development on federal and Indian lands.
Investigators said weak control by the Interior Department's Bureau of Land Management resulted from policies based on outdated science and from incomplete monitoring data.
The findings from the Government Accountability Office come amid an energy boom in the country and the increasing use of hydraulic fracturing, or fracking. That process involves pumping huge volumes of water, sand and chemicals underground to split open rocks to allow oil and gas to flow. It has produced major economic benefits, but also raised fears that the chemicals could spread to water supplies.
The audit also said the BLM did not coordinate effectively with state regulators in New Mexico, North Dakota, Oklahoma and Utah.