AN EMB145 DEVELOPED A FUEL LEAK OR SPILL AT THE GATE. THE ACFT WAS EVACUATED; BUT AN EMER WAS NOT DECLARED.

Narrative

WHEN PARKED AT GATE IN ZZZ; COCKPIT CREW WERE DOING NORMAL PREFLT ACTIVITIES WHILE BOARDING ACFT. FLT ATTENDANT WAS LOOKING OUTSIDE TO SEE IF EVERYONE WAS ON BOARD AND NOTICED A MASSIVE FUEL LEAK OUT OF THE L WING! NO ONE HAD SAID ANYTHING ABOUT THIS TO US PRIOR TO THE FLT ATTENDANT EVEN THOUGH THERE WERE SEVERAL GND PERSONNEL AROUND THE ACFT. THIS INCLUDED THE BAGGAGE LOADERS CURRENTLY LOADING BAGS AND THE GATE AGENT WHO WAS BOARDING THE ACFT. AS SOON AS THE FLT ATTENDANT INFORMED ME OF THIS SITUATION WE STARTED DEPLANING THE ACFT AS A PRECAUTION. I THEN PULLED OUT THE GOM AND FOLLOWED PROCS EXACTLY AS SPELLED OUT (FUEL SPILLS). THE PROB THAT I HAD WITH THE SITUATION WAS THAT THE GATE AGENT; AFTER THE FLT ATTENDANT AND I HAD TOLD THE PAX TO DEPLANE; TOLD THEM TO GO BACK ON BOARD AND GRAB THEIR BAGS AND LET THEM JUST MILL AROUND THE ACFT. I THEN WENT AND TOLD THE PAX TO GO INSIDE THE TERMINAL AND INFORMED THE GATE AGENT THAT THEY WERE NOT ALLOWED BACK ON THE ACFT. THE FUEL TRUCK WAS LEFT RUNNING NEXT TO THE ACFT AS WELL AS SEVERAL BAGGAGE CARTS AND THE BAGGAGE LOADER INSTEAD OF BEING DRIVEN AWAY FROM THE SPILL PER OUR PROCS DESPITE ME TELLING THEM TO DO SO.