An investigation by the Government Accountability Office (GAO) found that significant amounts of natural gas on federal lands are being wasted each year at the expense of taxpayers and the environment.

The natural gas waste is adding harmful methane gasses to the atmosphere and costing taxpayers more than $23 million annually in lost sales, reported The Associated Press.

The GAO said the Bureau of Land Management (BLM) didn't conduct necessary production inspections on hundreds of high-priority oil and gas wells to ensure that the federal government was receiving the correct amount of royalties from the gas extraction companies. It didn't complete inspections on 19 percent of those wells in 2013, according to GAO.

The GAO also said it had advised BLM since at least 2010 that 40 percent of burned or vented natural gas could be captured economically and sold, but the agency never updated its guidelines to facilitate the recommendation.

Capturing that gas would be the equivalent of removing 3.1 million cars from the road, or shutting down four coal-fired power plants, according to GAO and Environmental Protection Agency estimates.

"The Interior Department has known for at least a decade that companies have been wasting natural gas from oil and gas wells on public lands," said Sen. Ron Wyden, D-Ore, reported AP. "Venting and flaring natural gas from these wells hurts the environment and speeds up global warming, and it shortchanges the taxpayers."

The department acknowledged that it has a responsibility to recover lost taxpayer revenue and protect the environment, and said it is working on updating its rules and is taking significant steps to improve its data on venting, AP reported.