Six U.S. refineries ravaged by Hurricane Katrina remain down on Wednesday and at least four of these facilities could be out of operation "for months," Energy Information Administration chief Guy Caruso told a House panel on Wednesday. EIA is the statistical arm of the Energy Department. Those refinieres still out "will probably take longer" to restore, Energy Undersecretary David Garman told the House Energy and Commerce Committee. The Energy Department expects one of the six refineries to be fully operational by the end of Wednesday and another to take up to two weeks, according to an assesment released Wednesday