The raw material for the new petrochemical plant proposed in North Dakota will be ethane that comes from natural gas, a resource North Dakota has struggled to effectively handle in the oil boom.

Natural gas is abundant in the same wells that produce oil in the Bakken, but it's not easily transported and prices for it slumped around 2007, removing some of the incentive for oil companies to find a way to get it to market.

As recently as September 2011, 36 percent of the natural gas produced in North Dakota was burned off ("flared") at the wellhead. The flaring lights up northwest North Dakota like a huge city at night, and the wastefulness and environmental impact have been a sore spot for North Dakotans

"When the field first started going, there was a lack of gathering systems and we did a lot of flaring, and that's not abnormal for immature fields," Andy Peterson, president of the North Dakota Chamber of Commerce, told me on Wednesday. "What is normal is that you start capturing some of the stuff and using everything. That's what industry wants – they want to use every little bit of the raw product that they can."

The proposal by Badlands NGL to build a $4 billion plastics factory in North Dakota is the latest in a series of announcements of new factories that will use various components of natural gas to make other products – fertilizer, in most cases. These proposals highlight one of the quiet changes in the oil patch in 2014: growth in the state's natural gas processing capacity.

With the expansion of the Tioga plant in Williams County, and Golden Creek II in McKenzie County, natural gas processing capacity rose this year from 1 billion cubic feet to 1.3 billion cubic feet per day – a 30 percent increase.

Natural gas flaring in absolute terms has continued to rise, to an all-time high of 10.8 billion cubic feet in August.

North Dakota still doesn't have quite the capacity to process all the natural gas that comes out of the ground, but as a share of all natural gas production, North Dakota and the oil industry have been making progress against flaring. They're now flaring 27.7 percent of what comes out of the ground – still more than the goal of 26 percent by the fourth quarter of 2014, but you can see improvement over the past few years.

The North Dakota Industrial Commission's goal is to capture 90 percent of all natural gas in the state by 2020. That's still a ways off, but projects like the petrochemical plant are what will help make it happen.

Peterson, the chamber president, progress will come as the oil industry becomes more sophisticated in its use of the natural resources it pulls from the ground, and the Badlands petrochemical plant is a good example of that.

"It really is a reflection of this oil industry starting to mature and become more than just pumping oil out of the ground," he said. "Now we're using some of the byproducts to do advanced processing of some of those chemicals here in North Dakota."