Moody's Investors Service yesterday affirmed its "Ca" rating and negative outlook on Alabama's bankrupt Jefferson County, sewer revenue warrants, Reuters reported yesterday. The rating, deep in junk territory, affects $3.1 billion of outstanding debt. Moody's said that its rating reflected an expectation that holders of the county's defaulted sewer debt would only recover between 35 percent and 65 percent of the bond's value. It said the county's plan of adjustment being considered by creditors would "lead to a recovery toward the high end of the Ca rating recovery."