WILLISTON, N.D. (AP) _ North Dakota Water Commission officials say the state's oil industry used at least 5.4 billion gallons of water in 2012, an increase of 75 percent from 2011.
About 70 percent of the water was used for hydraulic fracturing, with at least 2 million gallons of water pumped into the ground at each well.
Hydraulic fracturing, also known as fracking, involves pumping water, sand and chemicals underground to break up shale rock and allow the oil to flow.
The water commission has approved permits for the oil industry to use 18.9 billion gallons of water. Hydrologist Bob Shaver says while it might seem like a lot of water, the state is being careful to make sure water sources are not being depleted.