FUEL SPILL ONTO THE RAMP.

Narrative

I WAS NOTIFIED BY EVV GND THAT FUEL WAS VENTING OUT OF OUR L (UPWIND) WING. WE HAD DIVERTED FROM STL TO EVV DUE TO WX AND MISSED APCH. I ACKNOWLEDGED THE ADVISORY AND WAS UNCONCERNED SINCE IT WAS COMMON FOR MD-80/DC9 ACFT TO VENT FUEL ON SLOPING RAMPS. AFTER THE CALL; I LEFT THE ACFT TO PICK UP PAPER WORK AND WALKED UNDER THE L WING TO FIND FUEL OUT AT THE WINGTIP AND WATER DRIPPING FROM UNDER THE WING FROM MELTING FROST. UPON MY RETURN TO THE ACFT; I WAS STOPPED BY THE EVV ARPT SAFETY OFFICER WHO EXPRESSED CONCERN ABOUT 'ALL' THE FUEL. I TOLD HIM THAT THERE WAS SOME FUEL; BUT MOST OF IT WAS WATER AND THAT ANY FUMES FROM THE FUEL WERE MOVING IN AN UPWIND POS; AWAY FROM THE ACFT. HE FELT THAT WE SHOULD GET THE PAX OFF THE ACFT AND CLEAN UP THE SPILL. I TOLD HIM THAT IT WOULD BE THE CAPT'S DECISION. I DID TELL THE CAPT OF HIS CONCERNS AND WE BOTH FELT THAT IT WOULD BE SAFE TO MOVE THE ACFT. WE MOVED THE ACFT WITHOUT ANY INCIDENT. SUPPLEMENTAL INFO FROM ACN 301627: SIZE OF SPILL WAS ESTIMATED BTWN 5-10 GALLONS. I FELT IT WAS NOT A FIRE HAZARD AND THAT IT WAS SAFER TO START UPWIND (R) ENG AND TAXI AWAY FROM SPILL RATHER THAN WAIT UNTIL CLEAN-UP EQUIP ARRIVED AND CLEANED FUEL. THERE WERE NO TUGS AVAILABLE TO MOVE ACFT.