Minnesota Democratic U.S. Sen. Al Franken and U.S. Rep. Collin Peterson tell the federal Environmental Protection Agency to not require North Dakota electrical power plants to install “expensive and unproven” devices to curb pollution.

The pair wrote a letter to EPA saying the costs of the technology probably would be passed on to western Minnesota families, farmers and businesses who comes from North Dakota.

“We support the goal of the Clean Air Act to protect human health and the environment,” the two wrote to EPA. “It makes sense to invest in pollution control technologies when there is proven public health or environmental benefit. However, we have not seen assurances from EPA that SCR (selective catalytic reactor) technology is effective in reducing pollution from power plants burning North Dakota lignite coal.”