The Associated Press reports that more than 300 oil pipeline spills have occurred in North Dakota in the past two years, but not one of them has been reported to the public.
Earlier this month, a massive leak was discovered in a wheat field in a rural part of the state. While the exact amount of oil spilled is not clear, it's been estimated to be more than 20,000 barrels. The AP said the leak was not revealed for 11 days and was addressed it only after the AP sought information.
Records obtained by the AP show that so far this year, North Dakota has recorded 139 pipeline leaks that spilled a total of 735 barrels of oil. In 2012, there were 153 pipeline leaks that spilled 495 barrels of oil, data show.
The AP report said that regulators are reviewing the policies about when to publicly report spills and leaks. The state also is reviewing a better system to track such incidents.
North Dakota now produces a million barrels a day and in the past year added nearly 2,500 miles of new pipelines to its existing 17,500 miles of pipelines.