What was found
BLUE RESOVOIR LO LEVEL AT FL 310/ BLUE PUMP OFF REMAINDER OF FLIGHT. PRIOR TO PUMP SHUTDOWN, PRESSURE 450 PSI. ECAM ALERT AT RED DOT ON OVERHEAD. CREW DECLARED AN EMERGENCY BUT TAXIED TO RAMP/GATE UNDER ACFT ENGINE POWER. AT BLOCK-IN THERE WAS NO SIGNS/EVIDENCE OF FLUID LEAKAGE ANYWHERE FROM ACFT. ALL INDICATORS COCKPIT AND EXTERIOR SHOW NEAR EMPTY INDICATIONS. STILL INVESTIGATING PROBLEM. DRAINED BLUE SYS RVSR, MEASURED OUT 2.5 GALLONS OF HYDR FLUID. INSTALLED BLUE SYS QTY TRANSMITTER I/A/W M/M 29-31-11-04 LEAK AND OPS CHECKS GOOD ACFT OK FOR SERVICE.