Associated Press:

North Dakota oil drillers are falling far short of the state’s goals to limit the burning of excess natural gas at well heads, five years after the state adopted the rules to reduce the wasteful and environmentally harmful practice.

The industry has spent billions of dollars on infrastructure but is at least two years from catching up, and regulators are projecting that the state’s increasing gas production will still outstrip that new capacity.

Environmentalists and even a key Republican say the problem will persist as long as the state doesn’t take a tougher approach with the industry, which has largely avoided financial penalties.

Flaring is the practice of burning off natural gas that is produced as a byproduct of oil drilling. It’s a picturesque feature of the oil patch, especially at night, but it means wasted money and unnecessary carbon dioxide emissions that worsen global warming.

In 2014, when more than one-third of that gas was being burned off, North Dakota began requiring oil companies to limit flaring to no more than 15 percent by 2016, and to 10 percent by 2020. The national average for flaring is less than 1 percent.

In March, drillers produced a record 2.8 billion cubic feet of natural gas per day, but about 20 percent of it went up in flames. That was well above the current limit of 12 percent — and was enough to heat all North Dakota homes for a month 10 times over, according to an analysis by the Legislature’s research agency. March also was the 13th month in a row that drillers missed the target.

More: As North Dakota oil soars, so does waste of natural gas