Jim Hoy, of Cassoday, Kan, left, and his son Josh Hoy watch prairie grasses burn on the younger Hoy's Flying W Ranch near Clements, Kan. Saturday, April 16, 2011. (AP Photo/Charlie Riedel)

Topeka ? When ranchers in the Flint Hills region of Kansas burn grasslands in the spring, people as far away as Omaha and Lincoln, Neb., know about it.

Nebraska officials say the density of smoke and fine particles in the air sometimes gets so heavy that it poses a health risk to the public, especially for people with asthma or other respiratory ailments.

Now, a Kansas environmental group is urging the Environmental Protection Agency to step in and order Kansas to impose tighter controls on grass burning.

Earlier this week, the Kansas chapter of the Sierra Club wrote a letter to the EPA’s regional administrator in Kansas City, Kan., urging the agency to order the Kansas Department of Health and Environment to adopt a mitigation plan to protect air quality in the region.

But the action comes with just four weeks remaining before President-elect Donald Trump’s new administration takes the reins of the federal government, including the EPA, and while Republicans in Congress are urging the Obama administration not to enact any new regulations before the Trump administration takes office.

“We think there’s a better chance of Region VII to do the right thing now rather than wait for whatever comes afterwards,” said Craig Volland, who chairs the Kansas Sierra Club’s Air Quality Committee. “It really comes down to whether EPA, at any level, is going to address this problem in any way.”

Volland said the state’s current “Smoke Mitigation Plan” dates back to December 2010, in the final weeks of then-Gov. Mark Parkinson’s administration. It was aimed at reducing the number of days when levels of ozone and other pollutants exceed federal health guidelines.

Prescribed burning of grasslands in the spring is considered vital to the Flint Hills ecosystem because it kills off invasive weeds and shrubs before they take root in the ground and promotes growth of native grasses that ranchers depend on to feed cattle and other livestock.

But depending on weather conditions and the number of acres being burned at any one time, those controlled burns can have a serious impact on air quality in surrounding areas.

In the first five years after the state plan took effect, Volland said, communities in Kansas actually had more days in which air pollutants exceeded federal limits than it had in the five years before the plan took effect.

And because the winds in Kansas tend to come from the south during the months when burning occurs, communities as far away as eastern Nebraska sometimes feel the heaviest brunt.

“It can be a pretty significant problem for us,” said Gary Bergstrom, senior environmental health specialist for the Lincoln-Lancaster County Health Department. “We’ve seen some funky stuff happen.”

One of the biggest public health concerns, Bergstrom said, is what’s known as “fine particulate matter,” tiny particles of ash and soot in the air that can can cause short-term health problems even for healthy people, and which can severely aggravate chronic health problems such as asthma and heart disease.

In April 2014, air quality monitors in Lincoln recorded four days when fine particulate matter exceeded the EPA’s recommended levels, including one day when it surpassed 150 parts per billion, the point considered to be “unhealthy” air quality, and more than three times the limit for what is considered “good” air quality.

“We’ll field phone calls from people who call and ask why air is so bad, where is smoke coming from,” Bergstrom said.

The EPA requires states and many municipalities to monitor air quality on a regular basis, and areas that routinely exceed federal pollution limits can be ordered to take corrective action.

Until recently, though, Volland said Kansas could ask for exemptions for what are called “exceptional events,” essentially deleting them from the data because they don’t necessarily occur on a regular basis.

But in October, Volland said, EPA tightened its rule so that when pollution levels exceed federal limits three or more times in three years, they are considered “historically documented or known seasonal events” that can trigger a requirement for a new mitigation plan.

Officials at the Kansas Department of Health and Environment and the Kansas Department of Agriculture did not respond to requests for comment Tuesday.

Volland said it’s possible that the EPA won’t issue any orders for Kansas in the waning days of the Obama administration. But he said he does think the regional office, which has jurisdiction over both Kansas and Nebraska, still has plenty of time to initiate discussions between the two states to come up with a better plan.

“I think this thing is going to be pretty much under the radar for the first year when there’s going to be a long confirmation hearing for the new EPA administrator,” Volland said. “Even under other new administrations, it takes a long time to get around to assigning the regional administrators. I think they’re going to be arguing about so many things (at the national level), they won’t get around to this for quite a while.”