BISMARCK (AP) -- Gov. Jack Dalrymple, Attorney General Wayne Stenehjem and a group of energy executives argued with environmental activists Thursday about the best way to reduce haze from North Dakota's coal-burning electric power plants.
The federal Environmental Protection Agency has drafted rules that would require some North Dakota plants to use a method for reducing nitrogen oxide pollution that is costlier than a procedure favored by the state Health Department.
The Health Department normally administers federal clean-air rules in North Dakota. The EPA moved to override some of the state's authority after federal and state health officials could not agree on how some power plants should address federal restrictions on pollution-caused haze.
At an EPA hearing in Bismarck on Thursday, Dalrymple said the state's plan would cut nitrogen oxide pollution by about half by using technology that has been proven to work in North Dakota's power plants. Most of them use lignite, a type of low-quality coal.
The federal agency's proposal would require much most expensive technology. It estimates its plan could cut nitrogen oxide emissions by 90 percent, but Dalrymple and utility executives who spoke at Thursday's hearing said no company that sells the equipment would guarantee its success with North Dakota lignite.
In any case, the visual improvement would be barely perceptible to the human eye, the governor said.
Stenehjem said the EPA was illegally ignoring the state's own anti-pollution work, and said the state would challenge the agency in court if it pressed ahead to implement the proposed rules.
Stenehjem called the duel a "choice between an ill-considered and unnecessarily expensive EPA proposal that produces an inconsequential result, and ... a well-reasoned, scientifically based and economically sound North Dakota proposal that will continue our longstanding commitment to protecting our environment."
At a news conference before Thursday's hearing, environmental activists supported the EPA rules, saying the pollution-control approach the agency has advocated has been used successfully in a number of states.
"We have workable solutions here. This shouldn't be a matter of choosing between clean air and affordable energy," said Jeremy Nichols, a spokesman for WildEarth Guardians, a nonprofit environmental group based in Denver. "Let's not settle for a second-rate plan that does not cut the haze, and does not ensure adequate protection of public halth."
Nitrogen oxide can worsen the breathing problems of people who have asthma. However, the rules dispute is focused on reducing pollution-caused haze near some of western North Dakota's most environmentally sensitive areas, including the Theodore Roosevelt National Park and the Lostwood National Wildlife Refuge.
The agency says its preferred approach will also improve the view in the Boundary Waters wilderness area in northern Minnesota, and in South Dakota's Wind Cave and Badlands national parks.
The EPA's Bismarck rules hearing ends Friday. The agency is taking written comments on its proposal until Nov. 21.
Wayde Schafer, a North Dakota spokesman for the Sierra Club, said the EPA's move would freshen the state's air quality everywhere.
"If you can see the air," Schafer said, "how is that not a health problem?"
Executives for companies that own power plants and coal mines in western North Dakota testified against the proposed EPA rules. They included Basin Electric Power Cooperative, of Bismarck; Montana-Dakota Utilities Co., of Bismarck; Allete Inc., of Duluth, Minn.; Great River Energy, of Maple Grove, Minn.; and Minnkota Power Cooperative, based in Grand Forks.
For Minnkota's Milton R. Young power station in western North Dakota, the EPA rules would require the cooperative to spend $500 million to install "unproven" pollution-control equipment, compared with the $35 million the state Health Department's plan would require, Dalrymple said.
Robert "Mac" McLennan, Minnkota's president, said the 130,000 rural electric ratepayers who buy the cooperative's power have already seen their rates rise 34 percent this year to pay for a $425 million investment in pollution controls.
The latest EPA proposal would require another sharp increase in rates, McLennan said.
"The worst part of it is, I won't be able to rationally give (customers) an answer for why it's happening," McLennan said. "I can't guarantee them that what's being proposed, from a technological perspective, will even work ... We're not even sure that it's going to get visibility improvement for the average North Dakotan."