The Environmental Protection Agency is trying to keep these concerns in mind as it approaches a decision about whether to allow E15 blends (15 percent ethanol) at the pump for normal "gas" pumps (currently E85 is sold at select gas stations from non-gas pumps).  The EPA faces the noisy voice of midwest legislators (whose constituents profit from corn ethanol) and ethanol lobbyists.

Later today a final decision may be announced.  According to an EPA spokesperson, "EPA remains committed to making an announcement by the deadline of Dec. 1."

Most pumps are currently E10 (featuring 10 percent ethanol).  Still, this use pales in comparison to the 11 billion gallons of ethanol next year and 36 billion gallons by 2022 that Congress has required that the nation use.  The ethanol mandate was endorsed and signed into law by former President George W. Bush in 2007.  However, the initiative currently lacks teeth; with E10 pumps it is estimated that less than half of the 2022 usage goal will be reached.

Automakers generally oppose increasing the amount of ethanol at the pump.  They say that E15 blends will corrode the majority of current gasoline engines.  Industry advocates, though, admit that the past ethanol mandates aren't in line with current consumption.  Describes Mike Stanton, CEO of the Association of International Automobile Manufacturers, the trade group representing major foreign automakers, "We're on a collision course here."

Given that opposition, the EPA may punt and try to delay the decision, contrary to its comments.  That would give it more time assess the impact of higher-ethanol blends on engine longevity, or give automakers funding to carry out such an assessment.  Congress, however, is trying to force the agency's hand.  Four farm-state senators, led by Ben Nelson, D-Neb., have introduced a measure that would force the EPA to allow E15 blends.

The automakers aren't the only ones worried about such a measure.  The International Snowmobile Manufacturers Association wrote a letter to the EPA warning that allowing E12 or E15 blends could cause "irreparable harm" to the 1.8 million registered snowmobiles in the U.S. They warn that this, in turn, could lead to economic damage in northern U.S. states, such as Michigan.  Lobbies for the marine, small engine, and motorcycle industries have also voiced opposition to increasing the amount of ethanol at the pump.

Ethanol, in its current food-based form, seems to be a lose-lose situation for the consumer, driving higher prices both at the pump and on food; promoting carbon emissions (and possibly warming), in addition to other pollutants; and corroding engines.  However, given the fact that certain states in the midwest stand to profit substantially on ethanol, and give Congress's ethanol-friendly nature, one way or another the measure seems likely to be put into effect.  The likely result will be that E12 or E15 pumps will likely become the standard across the nation.

A new bill is also pending in the Senate, introduced by Sen. Sam Brownback, R-Kan., which would mandate that automakers make 50 percent of their fleets E85-compatible by 2012 and 80 percent by 2015.  Currently E85 sells for approximately $2.23 a gallon versus $2.63 a gallon for gas.  However, ethanol is practically 24.1 percent less energy intensive, so it's more expensive to the consumer to drive on ethanol fuel than gasoline.

Updated Tues, Dec. 1, 2009 12:03 p.m.:
The EPA indeed decided to punt and push back the decision, despite their previous comments.  The agency says it will decide sometime in the middle of next year.  It announced the decision in a letter to Growth Energy, an ethanol lobby.

Writes the EPA:

Although all of the studies have not been completed, our engineering assessment to date indicates that the robust fuel, engine and emissions control systems on newer vehicles (likely 2001 and newer model years) will likely be able to accommodate higher ethanol blends, such as E15. However, we continue to evaluate the question of component durability when E15 is used over many thousands of miles and there is an ongoing study being conducted by D.O.E. that will provide critical data on this issue.

Ethanol supporters are generally taking the response as a positive one. In particular, cellulosic ethanol firms like POET are happy with it as it will give them time to bring their facilities online.  Describes POET CEO Jeff Broin, "We were pleased that the EPA’s letter shows a clear path to E15. Without increasing the base blend of ethanol to E15, it will be impossible to achieve the targets set in the Renewable Fuel Standard and there will be no market for cellulosic ethanol. POET is spending tens of millions of dollars to commercialize the production of ethanol from harvest leftovers but needs E15 to be certain there will be a market for the product."

Corn ethanol lobbyists, though, are eager to cash in quickly and may push for Congress to pass legislation rushing the E15 blend into approval.