EPA urged to withdraw new transportation emissions model 

Source: Amanda Peterka, E&E reporter • Posted: Tuesday, March 17, 2015

Two states and two pro-ethanol organizations have petitioned U.S. EPA over what they call a “defective” model for determining ethanol’s air pollution contribution.

In their petition, Kansas, Nebraska, the Energy Future Coalition and the Urban Air Initiative say that the MOVES2014 model released in October incorrectly attributes harmful air emissions to ethanol in petroleum gasoline. They are asking EPA to withdraw both the model and an underlying study.

“The key fact obscured by the MOVES model is that blending ethanol into ordinary gasoline is good, not bad, for emissions,” said Dave Vander Griend, president of the Urban Air Initiative, in a statement today. “Ethanol does this by diluting the most harmful components of gasoline with its own clean octane.”

The states and organizations separately challenged the model in December in a lawsuit in the U.S. Court of Appeals for the District of Columbia Circuit. EPA’s response to the suit is due in August, according to the briefing schedule set by the court.

The computer model made available in October is an update to EPA’s Motor Vehicle Emission Simulator (MOVES), which was first released in 2009 and last revised in 2010.

The update is based on millions of emission test results and takes into account new data, including the air impact of adding ethanol gasoline, according to EPA. The agency says the model is the “most up-to-date assessment of on-road mobile source emissions” and the best tool for measuring the transportation sector’s greenhouse gas emissions.

EPA has encouraged all states except California — which uses its own model — to use the model for analyses needed to shape required Clean Air Act pollution control plans. In two years, EPA intends to require the model for certain types of air quality analyses (E&ENews PM, Oct. 7, 2014).

The majority of gasoline sold in the United States contains about 10 percent ethanol. According to the petition dated March 6, the model and the study of transportation emissions that serves as its basis “seriously mischaracterize” the air pollution impacts from adding ethanol to gasoline.

According to the petition, the model and study attribute emissions of particulates to ethanol instead of to the hydrocarbon aromatics added to gasoline.

“This is a story of data manipulated to produce a policy-driving scientific model whose results are precisely the opposite of what occurs in the real world,” the petition says.

The petition references studies done by the Urban Air Initiative — a pro-ethanol group focused on gasoline aromatic compounds — and auto engineers showing that adding ethanol to gasoline lowers harmful air emissions.

In the petition, Kansas and Nebraska argue that the model could lower their revenue from agricultural industries because it encourages them to write Clean Air Act plans that limit the sale and consumption of ethanol.