Jill Schramm/MDN Trucks create a plume of dust as they travel up Ward County Road 18 Wednesday. The Ward County Highway Department wants to use oil-field produced water to settle dust on its graveled haul roads.

Oil-field brine might be low risk for metals and gases, but does it contain radiation?

The Ward County Commission determined to find out Tuesday after receiving a letter from a Minot couple questioning the oil-field brine that the county wants to use on certain roads for dust control.

“The question is about the radiation. That’s what the biggest concern is,” Commission Chairman Alan Walter said. “I think we need answers.”

The commission had voted July 3 to approve a request from the county highway department to purchase a fiberglass storage tank and distribution equipment for a program using produced water from a Renville County oil well in the Madison Formation to control dust on gravel roads heavily used by county trucks, such as in hauling gravel.

Walter, who had voted against acquiring the equipment, had stated he was hearing from people concerned about the application of corrosive chemicals on the roads. Chlorides, such as the magnesium, calcium and sodium chlorides in produced water, have corrosive qualities. Magnesium and calcium chlorides are commonly used in dust control, and salts are used in de-icing roads too.

Well brine must be tested and permitted by the North Dakota Health Department as environmentally safe for use on roads. The test measures hydrogen sulfide and heavy metals, for instance. The analysis does not include testing for radiation.

“We have looked at that concern previously,” said Karl Rockeman, director of water quality at the department, contacted in Bismarck by the Minot Daily News. “It’s something we are going to keep an eye on and probably do some on-going checking for.”

However, he said, tests currently don’t routinely check to see if oil-field brine contains radiation at levels higher than typically found in the natural environment. Should radiation exist, it would be a concern once the product dries because radioactive particles could become airborne, he said.

Rockeman said the state’s analysis compares the safety and effectiveness of brine samples to commercial products for dust control. Whether using oil-field brine or commercial products, there are necessary protocols for application to avoid risk to the environment, he said.

Older wells, like the one being considered by Ward County, are more likely to pass testing than newer wells in the Bakken, which are deeper. Over the years, various counties and the state have used brine on certain roads.

“A lot of them have found that some of the commercial products can be more effective,” Rockeman said.

The commission plans to check with the North Dakota Transportation Department regarding its past experience with produced water and decision to switch to other products.

The Ward County Highway Department wants to try oil-field brine as a cost-saving measure. Assistant county engineer Travis Schmit said the county could obtain the brine at no cost but would be responsible for its transportation.