A321
Aircraft Equipment Problem Less Severe
Flight Crew Returned To Gate
MEL
On taxi out after crossing runway 27R on the way to 27L we got an ECAM fault that said 'RIGHT WING OVERFLOW.'  We did the procedure and the overflow still existed. We verified this by looking out the cockpit window as well as ATC relaying visual confirmation from other aircraft. I shut down the right engine hoping this would stop the leak. I quickly called Mainteneance to ask their advise and they said taxi it back in on one engine if I felt comfortable. Unfortunately even with the right engine shut down the overflow still existed although it had diminished. At this point I knew that I could not taxi an aircraft spewing fuel back to the gate so I started the APU and shut down the left engine along with all the fuel pumps. This finally seemed to bring the overflow to a slow drizzle and it eventually stopped. My First Officer was a great help throughout this ordeal with good insight and advice as we needed to keep a lot of people in the loop: Maintenance; Ground; Operations; Flight Attendants; passengers; ETC. Firetrucks were dispatched and an airport fuel clean-up crew also came. The fuel clean-up was started and it was decided by the Airport Authority that the tug would make a practice pull to see if we could be towed without any fuel sloshing out of the wing. We were tugged a few hundred feet and unfortunately fuel overflowed from the wing. Airstairs and 3 busses were called to remove the passengers from the aircraft while we sat on the holding area next to the departure end of 27L. We all deplaned without an further issues and the passengers were taken to the terminal. I don't know exactly why the right wing was overflowing but I do know that an MEL had just been removed concerning a fuel pump or valve. (I don't remember which) I believe this maintenance that had just been done must have had something to do with the overflow.
On taxi out; A321 crew received 'RIGHT WING OVERFLOW' ECAM message. After completing the QRH procedure and visually confirming the venting fuel; crew shut down both engines to stop the fuel venting and the aircraft was towed to the gate. Cause of fuel venting was not reported. MEL for fuel pump or valve had been cleared before the flight.