9 February 2011

The US Environmental Protection Agency (EPA) recently released a draft report on the environmental and conservation impacts of biofuels production and use. The report—titled “Biofuels and the Environment: The First Triennial Report to Congress”—is the first of the EPA’s triennial reports to Congress required under the 2007 Energy Independence and Security Act (EISA). EISA requires EPA to revise the Renewable Fuel Standard (RFS) program to increase the volume of renewable fuel blended into transportation fuel from 9 billion gallons per year in 2008 to 36 billion gallons per year by 2022.

The report reviews impacts and mitigation tools across the entire biofuel supply chain, including feedstock production and logistics, and biofuel production, distribution, and use. The report focuses on:

  • Six feedstocks: The two most predominantly used (corn starch and soybeans), and four others (corn stover, perennial grasses, woody biomass, and algae) that represent a range of feedstocks currently under development. Because the RFS2 limits the amount of corn starch-derived biofuel that counts toward the volume requirement in 2022 to 15 billion gallons, an increased reliance on other feedstocks is predicted.
  • Two biofuels: Ethanol (both conventional and cellulosic) and biomass-based diesel, because they are the most commercially viable in 2010 and/or projected to be the most commercially available by 2022.

The EPA life cycle assessment—in agreement with the earlier conclusions published in the RFS2 Regulatory Impact Analysis—shows that some segments of the biofuel life cycle result in greenhouse gas (GHG) emissions; however, when the entire biofuel life cycle is considered, the EISA-mandated revisions to the RFS2 program are expected to achieve a 138-million metric ton reduction in CO2-equivalent emissions by 2022 compared to continued reliance on petroleum-based fuels.

While upholding its conclusion on the overall positive GHG impact of biofuels, the EPA identified a number of potential negative environmental effects from cultivation of biofuel crops. The analyzed environmental impacts include effects on water quality (e.g., erosion and runoff of fertilizers), water quantity, soil quality (increased soil erosion, decreased soil organic matter content, increased soil GHG emissions), air quality, and ecosystem (biodiversity loss). International effects were also analyzed, as increases in US biofuel production and consumption would affect many different countries due to the change of trade patterns and prices in response to global supply and demand.

To further address adverse impacts from biofuels, EPA recommended a number of actions, such as developing Environmental Life Cycle Assessments for biofuels and engaging the international scientific community in cooperative efforts to identify sustainable biofuel practices. Because biofuel impacts cross many topics and agency responsibilities, EPA intends to work in cooperation with other federal agencies and international partners, including the US Departments of Agriculture and Energy.

EPA will accept public comments on the draft report through February 28, 2011. An independent peer review meeting, open to the public, by a panel of experts convened by EPA will be held on March 14, 2011 in Arlington, VA. The final report will be published in 2012 on the EPA Biofuels web site.

The draft report has been criticized by US ethanol trade groups, including the Renewable Fuels Association and Growth Energy.

Source: US EPA