Senators Chuck Grassley and Joni Ernst of Iowa joined bipartisan colleagues in demanding answers from the Environmental Protection Agency regarding used cooking oil imports. The lawmakers want information on the agency’s process for verifying the authenticity of the imports. Responding to a congressional probe, Senior Customs and Border Protection official Troy Miller says the CBP considers UCO imports as pure even when co-mingled with virgin vegetable oil, such as palm oil. Based on that admission, the senators are slamming the EPA’s existing verification process as meaningless. “Without a robust verification process, the credibility of the Renewable Fuel Standard is at risk, and American farmers are likely missing out on key market opportunities,” the legislators said in a letter. “Through August, the U.S. has imported a historic 3.2 billion pounds of UCO this year, which is enough product to displace about 270 million bushels of soybeans. American farmers should be first on the list.”