Topeka ? Kansas Attorney General Derek Schmidt filed suit in federal court this week challenging the U.S. Environmental Protection Agency’s new system for calculating motor vehicle fuel emissions.

Schmidt filed the challenge Monday with the Washington, D.C., Circuit Court of Appeals, which handles direct challenges to federal agency actions.

The battle is over how states document their compliance with federal clean air policy for reducing air pollution and greenhouse gas emissions. That, in turn, determines whether states can qualify for various types of federal funding, including highway and transportation funds.

But Schmidt says the new model, the 2014 version of EPA’s Motor Vehicle Emissions Simulator, or MOVES2014, which states and urban communities use to calculate fuel emissions being generated in their territory, particularly fine particle emissions that contribute to respiratory illness and other diseases.

One of the biggest changes in the 2014 model is how it calculates emissions from ethanol-blended gasoline. The previous model, adopted in 2010, only considered 10 percent ethanol blends, or E-10 gasoline.

Two outside groups that promote the use of ethanol, the Urban Air Initiative Inc. and the Energy Future Coalition, which have joined Schmidt’s challenge of the EPA rule, say the new model also takes into account blends of higher concentration such as E-20 and E-85 and assumes that the higher concentrations produce more harmful emissions.

“It is wrong not just as a matter of degree, but of polarity, such that positive has become negative,” those groups wrote in a joint letter to EPA Administrator Gina McCarthy in October, shortly after the new emissions model was published in the Federal Register.

Schmidt also argues that EPA adopted the new model improperly.

“EPA’s requirement that states use this faulty model was unlawfully adopted without notice and opportunity for comment,” Schmidt said in a news release announcing the challenge.

“This is an example of the EPA imposing its will on the states rather than working cooperatively toward the shared goal of cleaner air. We are asking that this model be rejected and replaced with a model that more accurately reflects the true emission effects of ethanol.”

The concern is that using the new model could show states and metropolitan areas out of compliance with clean air rules and thus force them to adopt strategies to reduce the use of ethanol.

In their joint letter to EPA, the two pro-ethanol groups argued that the MOVES2014 model is based on a study by the Coordinating Research Council, a nonprofit organization they say is supported by the American Petroleum Institute and a group of auto manufacturers.

EPA spokeswoman Christie St. Clair said the agency could not comment on the lawsuit because it had not yet received the legal complaint. But she strongly defended the new model and flatly denied Schmidt’s charge that it was adopted without scientific evidence or public input.

“MOVES2014 is the best available tool for estimating mobile source emissions,” St. Clair said in an email. “It is based on extensive data and technical analysis related to emissions of cars, trucks, and nonroad engines and equipment.”

“The fuel effects study was subjected to review and comment by many technical experts external to EPA during its design, and it underwent a rigorous independent peer review after data analysis was completed,” she continued. “We are confident that the results of the fuel effects study and its application in MOVES2014 represent the best fuel effects modeling information available.”

EPA officially released the MOVES2014 model in October and gave states a two-year grace period before they have to begin using it. One of the biggest changes in the 2014 version is a method for calculating emission of toxic pollutants from ethanol.

In addition to the two pro-ethanol groups, the state of Nebraska, a major producer of corn and ethanol, has also joined the challenge.