WASHINGTON, D.C. – A letter of concern has been sent to the U.S. Treasury Department by a bipartisan group of U.S. senators who are calling for guidance in the area of alternative-fuels policy, according to the Web site www.calstart.org/. The Alternative Fuels Infrastructure Tax Credit was enacted in the Energy Policy Act of 2005, with provisions for tax credits for properties becoming effective as of Jan. 1, 2006. The letter says there has been an increasing demand for alternative fuels, such as E-85 ethanol and B-20 biodiesel, and calls for preliminary guidance and rules to encourage those who provide feed stocks and build fueling stations. The letter, sent last week under the letterhead of Sen. Barack Obama (D-Ill.), was co-signed by 10 others from both parties, including Senators Sam Brownback (R-Kans.) and Joseph Lieberman (D-Conn.).