EPA plans ethanol air quality study

Source: Marc Heller, E&E News reporter • Posted: Tuesday, February 26, 2019

EPA will study the effect of ethanol emissions from vehicles on air quality as it seeks to settle a legal dispute with environmentalists who are skeptical of the environmental benefits of corn-based fuels.

The agency is planning a report on air pollution potentially tied to ethanol by March 30, 2020, according to a Federal Register notice last week. The information could ultimately affect the annual volumes of the alternative fuel that EPA mandates are included in the nation’s fuel supply under the federal renewable fuel standard.

The study, announced as a proposed consent decree, would partially settle a lawsuit the Sierra Club filed against EPA in 2017. The Sierra Club said EPA failed to do environmental reviews of the RFS as required by the Clean Air Act. That includes an “anti-backsliding study” to examine the effects on vehicle emissions and air quality.

The law requires that EPA either take measures to mitigate any negative air quality effects — which could include reducing renewable fuel volumes as part of a reset of the RFS — or determine that additional regulations aren’t necessary.

The Sierra Club’s fight against ethanol mandates is part of a broader concern among environmental groups over whether the measure has brought the benefits initially promised when RFS was established in 2005 and updated in 2007. Among other complaints, they say ethanol poses its own emissions challenges and that previously beneficial grassland has been converted to corn, which requires heavier use of farm chemicals.

The latest EPA notice refers to vehicle emissions, although other types of emissions — such as from plants that produce ethanol — are also at play as EPA examines the environmental effects of the law.

Past EPA studies have shown higher tailpipe emissions of nitrogen oxides from ethanol, but the agency said in a report to Congress last year that more study is needed on vehicle emissions, especially with fuel and engine technologies advancing.

The Renewable Fuels Association, an trade group representing the ethanol industry, has pointed to studies showing that higher-ethanol fuel such as E15 can improve air quality by creating less emissions tied to ground-level ozone and smog.