The TransCanada Keystone Pipeline is designed to deliver 590,000 barrels of crude oil each day. The pipeline's route would go through ten counties in the eastern part of South Dakota affecting about 600 landowners.
The PUC decision comes after many public hearings and debates on the project. The commission added 57 conditions before approving the construction permit.
Steve Kolbeck, a Public Utilities Commissioner, said there are limits to their authority.
"I understand the fear, and I understand the love of the land. I understand that no one knows what will happen in 50, 10 or 5 years from now... but I do feel comfortable with the conditions we have put on this pipeline and I feel it will be held to a safe and accountable manner," Kolbeck said.
But for landowners concerned about their drinking water, the conditions did not go far enough.
Kent Moeckly farms near Britton, South Dakota. He describes his land as wet and sandy soil that runs very close to the rural water aquifer.
"So they're attempting to lay that pipe right down in the surficial water, and if there would be a break in that area it would be just horrible what it would do it would just be a calamity," Moeckly said.
Moeckly refused to sign TransCanada's easement offer. The company would have paid him about $8,000 to cross one portion of his land. He said the agreement didn't protect him or the water if there was a spill. So now the company is taking him to court.
"Yes, we're being sued under the eminent domain statutes by the Transcanada Keystone Pipeline Company. I assume our case will go to trial this summer," Moeckly said.
Moeckly said he'd feel guilty if he didn't fight the project. He said TransCanada needs to route the pipeline away from the aquifer.
Originally the route was to follow Interstate 90 and use the state easements. Moeckly said the route has moved so many times the commission didn't have enough information about the acquifer near his home.
But PUC Chirman Gary Hanson said they have plenty of information and faith in other state regulatory agencies that are part of the permitting process, including agencies like the Department of Environment and Natural Resources. Hanson said between the state departments and the federal permitting process, there is enough oversite in the case of a spill or leak.
"This commission in working through this process does set precedent for future pipelines and with the proposed refinery there will no doubt be pipelines with that. So it is especially important we get this right the first time," Hanson explained.
That refinery Gary Hanson is talking about, is an oil-related project in the planning stages for eastern South Dakota.
County commissioners in Union County in the southeastern corner of South Dakota, have approved rezoning 3,000 acres for construction of what could be the country's first new oil refinery in decades. However there are many more hurdles for the project located in Elk Point, called the Hyperion Oil Refinery.
The TransCanada Keystone Pipeline said it's not planning to feed the proposed refinery with crude oil. But the maps show it runs close to Elk Point before cutting east through Nebraska toward southern Illinois.
TransCanada still needs federal approval for the pipeline to cross the border into the United States. Officials say they'll start construction through North Dakota in the spring of this year.